Application for the Reassessment of a Hazardous Substance under ...
Application for the Reassessment of a Hazardous Substance under ...
Application for the Reassessment of a Hazardous Substance under ...
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<strong>Application</strong> <strong>for</strong> <strong>the</strong> <strong>Reassessment</strong> <strong>of</strong> a<strong>Hazardous</strong> <strong>Substance</strong> <strong>under</strong> Section 63 <strong>of</strong><strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s and NewOrganisms Act 1996Name <strong>of</strong> <strong>Substance</strong>(s):Dichlorvos<strong>Application</strong> Number:HRC08004Applicant:Chief Executive ERMA New ZealandNovember 2010
ContentsExecutive Summary 5SECTION 1 – THE APPLICATION 141.1 Applicant details 141.2 Background to <strong>the</strong> application 141.3 Preparation <strong>of</strong> <strong>the</strong> application 151.4 Notification and Consultation 16SECTION 2 - THE RISK MANAGEMENT CONTEXT 182.1 Risk management context 182.2 Consideration <strong>of</strong> Outcome Scenarios 182.3 Identification and assessment process 192.4 Consideration <strong>of</strong> uncertainty 202.5 Ethical considerations 202.6 Principles <strong>of</strong> <strong>the</strong> Treaty <strong>of</strong> Waitangi (Te Tiriti ō Waitangi) 21SECTION 3 – THE SUBSTANCE AND ITS LIFECYCLE 223.1 Identification <strong>of</strong> <strong>the</strong> substance 223.2 Regulatory History in New Zealand 223.3 International regulatory position 233.4 Mode <strong>of</strong> action 233.5 Review <strong>of</strong> hazardous properties 233.6 Classification 253.7 Lifecycle 303.8 Use Scenarios 343.9 Existing Controls 39SECTION 4– IDENTIFICATION AND ASSESSMENT OF ADVERSE ANDBENEFICIAL EFFECTS (RISKS, COSTS AND BENEFITS) 404.1 Introduction 404.2 Incidents 404.3 Environment 414.4 Human health and safety 444.5 Summary <strong>of</strong> exposure risks to <strong>the</strong> environment and human health. 544.6 Society and communities 574.7 The market economy 584.8 Māori interests and concerns 644.9 International obligations 65SECTION 5 – LIKELY EFFECTS OF DICHLORVOS BEING UNAVAILABLE 665.1 Introduction 665.2 Comparative hazard assessment <strong>of</strong> alternative plant protection products 69SECTION 6 – PROPOSALS TO MANAGE RISKS 76Dichlorvos reassessment – application Page 2 <strong>of</strong> 436
6.1 Evaluation <strong>of</strong> options to streng<strong>the</strong>n existing controls 766.2 Evaluation <strong>of</strong> options to reduce risk by restricting use 816.3 Effect <strong>of</strong> proposed additional controls on <strong>the</strong> level <strong>of</strong> risk 81SECTION 7 – OVERALL EVALUATION 1057.1 Evaluation <strong>of</strong> options to reduce risk by restricting use 1057.2 Overall Evaluation 1077.3 Proposed additions and modifications to controls <strong>under</strong> section 77A 1107.4 Preliminary Recommendations 116Appendices 117Appendix A:Chemical and physical properties <strong>of</strong> <strong>the</strong> active ingredient andmethods <strong>of</strong> analysis 117Appendix B: Environmental Fate <strong>of</strong> dichlorvos 121Appendix C: Environmental Exposure modelling 124Appendix D: Ecotoxicity <strong>of</strong> dichlorvos 139Appendix E: Risk Assessment: Environment dichlorvos 145Appendix F: Human Toxicity <strong>of</strong> dichlorvos 155Appendix G: Human Health Risk Assessment 276Appendix H: Qualitative Descriptors <strong>for</strong> Risk/Benefit Assessment 381Appendix I: Data from which classifications derived by mixture rules were derived 385Appendix J: Current Controls 392Appendix K: Overseas regulatory action 411Appendix L: Parties consulted during <strong>the</strong> preparation <strong>of</strong> <strong>the</strong> application 421Appendix M: ACVM and o<strong>the</strong>r NZFSA administered legislation 422Appendix N: Plant & Food Research Report on Use 434Appendix O: References 435List <strong>of</strong> TablesTable 1. Dichlorvos-containing substances covered by this application 1 . 17Table 2. Identity <strong>of</strong> dichlorvos. 22Table 3. Classification <strong>of</strong> dichlorvos. 25Table 4. Classification <strong>of</strong> dichlorvos-containing substances. 26Table 5. Label rates and uses <strong>for</strong> dichlorvos-containing plant protection products. 30Table 6.Label rates and uses <strong>for</strong> dichlorvos-containing products <strong>for</strong> non-plantprotection uses. 32Table 7. Dichlorvos outdoor and indoor plant protection Use Scenarios. 35Table 8. Dichlorvos non-agricultural Use Scenarios. 36Table 9. Identification <strong>of</strong> potential sources <strong>of</strong> risk. 40Table 10.Summary <strong>of</strong> occupational risk quotients <strong>for</strong> <strong>the</strong> Use Scenarios <strong>of</strong>dichlorvos usage. 46Dichlorvos reassessment – application Page 3 <strong>of</strong> 436
Table 11.Table 12.Table 13.Table 14.Summary <strong>of</strong> Restricted Entry Intervals (REI) and restrictions <strong>for</strong> use <strong>of</strong>dichlorvos-containing substances. 52Summary <strong>of</strong> <strong>the</strong> level <strong>of</strong> risk posed by use <strong>of</strong> dichlorvos-containingsubstances. 55Identification <strong>of</strong> beneficial effects on society and <strong>the</strong> economy fromimportation and use <strong>of</strong> dichlorvos 59Comparative <strong>of</strong> hazard classifications <strong>of</strong> o<strong>the</strong>r insecticide activeingredients applied to products on which dichlorvos is used. 70Table 15. Summary <strong>of</strong> Use Scenarios. 81Table 16. Effect <strong>of</strong> additional controls on <strong>the</strong> level <strong>of</strong> risk. 82Table 17.Summary <strong>of</strong> risks <strong>for</strong> Use Scenarios and Outcome Scenarios <strong>for</strong>dichlorvos-containing substances. 107Table 18 Summary <strong>of</strong> benefits associated with scenarios. 108Table 19. Overall evaluation – summary <strong>of</strong> combined non-negligible effects. 109Table 20.Table 21.Table 22.Outcome Scenarios <strong>for</strong> approvals. ―Restricted use‖ includes withdrawal<strong>of</strong> specific Use Scenarios. 110Summary <strong>of</strong> <strong>the</strong> proposed variations to approvals <strong>for</strong> dichlorvos anddichlorvos-containing substances. 111Summary <strong>of</strong> proposed hazard classifications <strong>for</strong> dichlorvos anddichlorvos-containing substances. 114Dichlorvos reassessment – application Page 4 <strong>of</strong> 436
EXECUTIVE SUMMARYIn briefERMA New Zealand proposes that <strong>the</strong> approvals <strong>for</strong> dichlorvos and dichlorvos-containingsubstances be modified to restrict <strong>the</strong> way <strong>the</strong> substances are used, by prohibiting outdooragricultural or public area use, and applying additional use restrictions <strong>for</strong> o<strong>the</strong>r uses. ERMANew Zealand also proposes to modify <strong>the</strong> hazard classifications <strong>of</strong> dichlorvos anddichlorvos-containing substances.This is only a preliminary recommendation by ERMA New Zealand. A final decisionwill be made by members <strong>of</strong> <strong>the</strong> Authority itself, after consideration <strong>of</strong> publicsubmissions and evidence provided at public hearings.The Authority‘s decision will be based on whe<strong>the</strong>r or not <strong>the</strong> positive effects (benefits) <strong>of</strong>using dichlorvos outweigh <strong>the</strong> negative effects (risks and costs) <strong>of</strong> its use – after takingaccount <strong>of</strong> all safety precautions that might be imposed and <strong>the</strong> likely effects <strong>of</strong> <strong>the</strong> substancebeing unavailable. If <strong>the</strong> benefits outweigh <strong>the</strong> risks and costs, <strong>the</strong> Authority may approve <strong>the</strong>continued use <strong>of</strong> dichlorvos in New Zealand <strong>for</strong> some or all <strong>of</strong> its current uses (possibly withstricter controls or with fur<strong>the</strong>r restrictions on use). If <strong>the</strong> benefits do not outweigh <strong>the</strong> risksor costs <strong>the</strong>n <strong>the</strong> Authority may decide to revoke <strong>the</strong> approval <strong>for</strong> substances containingdichlorvos.The applicationThis application is made by <strong>the</strong> Chief Executive <strong>of</strong> ERMA New Zealand <strong>for</strong> <strong>the</strong> reassessment<strong>under</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s and New Organisms Act 1996 <strong>of</strong> dichlorvos and <strong>of</strong>substances containing dichlorvos.To assist in preparing this application, ERMA New Zealand has obtained in<strong>for</strong>mation from avariety <strong>of</strong> sources in New Zealand:Adria Crop Protection (Len Stulich)Auckland Regional Council (Sandi Murray)BOCEcolab (Eric Van Essen)Environment Bay <strong>of</strong> Plenty (David Phizacklea)Environment Canterbury (Ron McCraw)Fonterra (Roger Andela)Foundation <strong>for</strong> Arable Research (Nick Pyke)Greater Wellington (Ray Clarey)Horticulture New ZealandMAF Biosecurity (Vivien Thompson)Meadow Mushrooms Ltd (Gill Hoglund)Nor<strong>the</strong>rn Distributors (Les Bryant)Northland Cymbidium Grower‘s AssociationOrion Crop Protection (John Hicking)Dichlorvos reassessment – application Page 5 <strong>of</strong> 436
Rentokil (Jon Thompson)Precautionary approach to determining risksIn <strong>the</strong> absence <strong>of</strong> New Zealand-specific exposure data, <strong>the</strong> assessment largely usesenvironmental and human health models to estimate exposure. These models useconservative assumptions and may overestimate risks.This precautionary approach is consistent with <strong>the</strong> HSNO Act and regulations. These providethat where <strong>the</strong>re is scientific and technical uncertainty, <strong>the</strong> Authority must consider <strong>the</strong>materiality <strong>of</strong> <strong>the</strong> uncertainty and if <strong>the</strong> uncertainty cannot be resolved to its satisfaction, musttake into account <strong>the</strong> need <strong>for</strong> caution in managing <strong>the</strong> adverse effects <strong>of</strong> <strong>the</strong> substance.Use <strong>of</strong> dichlorvos in New ZealandFormulations containing dichlorvos have been registered <strong>for</strong> use in New Zealand since 1968.In New Zealand dichlorvos is used <strong>for</strong> <strong>the</strong> control <strong>of</strong> crawling and flying insects. Dichlorvosis used in agricultural and non-agricultural situations (Table ES. 1). This in<strong>for</strong>mationsummarises known use or label use patterns.Table ES. 1Summary <strong>of</strong> use <strong>of</strong> dichlorvos in New Zealand.Agricultural useVegetablesCerealsFruit (including tamarillo, persimmon, berries,passionfruit)Glasshouse crops (capsicum, cymbidium)Non-agricultural useIndoor/enclosed space treatment:Industrial, public access buildingsDomestic useOutdoor treatment <strong>of</strong> public areasUse in biosecurity fruit-fly monitoring.Mushroom houses8 substances containing dichlorvos are currently approved <strong>for</strong> use in New Zealand (TableES. 2). Only those substances used in agricultural situations require registration <strong>under</strong> <strong>the</strong>ACVM Act.Table ES. 2<strong>Substance</strong>s containing dichlorvos approved <strong>for</strong> use <strong>under</strong> <strong>the</strong> HSNO Act.<strong>Substance</strong> descriptionApproval numbersHSNO ACVMTrade namesDichlorvos [CAS #62-73-7] HSR002838 - -DDVP Insecticide Strip HSR000126 P007362 DDVP Insecticide StripFlammable aerosol containing 3.1g/litre dichlorvos and 8.7 g/litrepropoxurReady to use liquid containing 4.4g/litre dichlorvos and 9.6 g/litrepropoxurEmulsifiable concentrate containing1000 g/litre dichlorvosHSR000207 - BV2 Surface InsecticideHSR000209 - BV2 Surface Insecticide BulkHSR000211 P001132 NuvosDichlorvos reassessment – application Page 6 <strong>of</strong> 436
Aerosol containing 50 g/kgdichlorvosEmulsifiable concentrate containing1140 g/litre dichlorvosHSR000212- InsectigasP005877HSR000213 P006080 DivapJ72.03 [insecticide <strong>for</strong> export-only] HSR001757 - -ClassificationArmourCrop-InsecticideAs a result <strong>of</strong> <strong>the</strong> review <strong>of</strong> <strong>the</strong> hazard classifications as part <strong>of</strong> this reassessment, ERMANew Zealand proposes that dichlorvos and dichlorvos-containing substances are classified asdetailed in Table ES. 3.Table ES. 3Summary <strong>of</strong> <strong>the</strong> revised classifications <strong>for</strong> <strong>for</strong> dichlorvos and dichlorvoscontainingsubstances (shaded cells indicate changes to existing classifications).Hazard ClassDichlorvosReady touse liquidcontaining4.4 g/ldichlorvos& 9.6 g/lpropoxurHSR000209Emulsifiableconcentratecontaining1000 g/ldichlorvosAerosolcontaining50 g/kgdichlorvosEmulsifiableconcentratecontaining1140 g/ldichlorvosFlammableaerosolcontaining3.1 g/ldichlorvosand 8.7 g/lpropoxurHSR000207DDVPinsecticidestripHSRHSR HSR HSRHSRApproval #002838000211 000212 000213000126Flammability No No No No 2.1.2A No No NoJ72.03HSR001757Acute toxicityN/A,N/A,6.1B 6.1D 6.1C6.1C(oral)aerosolaerosol6.1D 6.1CAcute toxicity(dermal)6.1B 6.1E 6.1B 6.1D 6.1B No 6.1E 6.1CAcute toxicity(inhalation)6.1B No 6.1B 6.1C 6.1C No 6.1C 6.1BSkinirritancy/corrosion6.3B 6.3B 6.3B No 6.3B 6.3B 6.3B 6.3BEyeirritancy/corrosion6.4A 8.3A 6.4A No 6.4A 6.4A 6.4A 6.4AContactsensitisation6.5B 6.5B 6.5B 6.5B 6.5B 6.5B 6.5B 6.5BMutagenicity 6.6B No 6.6B 6.6B 6.6B ND 6.6B 6.6BCarcinogenicity 6.7B 6.7B 6.7B 6.7B 6.7B 6.7B 6.7B 6.7BReproductive/developmentalNo No 6.8A No ND ND ND NotoxicityTarget organsystemic toxicity6.9A 6.9B 6.9A 6.9B 6.9A 6.9B 6.9A 6.9AAquaticecotoxicity9.1A 9.1A 9.1A 9.1A 9.1A 9.1A 9.1A 9.1ASoil ecotoxicity 9.2D No 9.2D No 9.2D ND ND NDTerrestrial vert.ecotoxicity9.3A 9.3B 9.3A 9.3B 9.3A 9.3B 9.3B 9.3BTerrestrial invert.ecotoxicity9.4A 9.4B 9.4A 9.4A 9.4A 9.4B 9.4A 9.4ADichlorvos reassessment – application Page 7 <strong>of</strong> 436
Overseas regulatory status <strong>of</strong> dichlorvosDichlorvos-containing substances have been reviewed in a number <strong>of</strong> countries: United States<strong>of</strong> America (USEPA), Australia (APVMA), Canada (PMRA) and Europe (EU). Thesereviews have resulted in restrictions, prohibitions or voluntary removal from <strong>the</strong> market.Risks, costs and benefits <strong>of</strong> use in New ZealandThe risks, costs and benefits <strong>of</strong> <strong>the</strong> use <strong>of</strong> dichlorvos in New Zealand have been assessed.Exposure is based on how a substance is used. ERMA New Zealand carried out its exposuremodelling based on Use Scenarios detailed in Table ES. 4:Table ES. 4Use scenarios evaluated in this application.UseOutdooragricultural useUse Scenarios 1 – 8Indoor agriculturaluseUse Scenarios 9 –16Indoor nonagriculturaluseUse Scenarios 17 –25Domestic useUse Scenarios 26 –29Outdoor use inpublic areasUse Scenario 30Biosecurity useUse Scenario 31Manufacture <strong>for</strong>exportUse Scenario 32<strong>Application</strong> detailsUsed on variety <strong>of</strong> crops (including berries, vegetables, cereals, fruit);800 – 2052 g a.i. / ha, up to 2 times per year, low boom application <strong>of</strong> EC <strong>for</strong>mulation.Variety <strong>of</strong> glasshouse crops and in mushroom houses;0.05 g a.i. / m 3 , up to 2 times per year, automatic fogging application <strong>of</strong> RTU gas orEC <strong>for</strong>mulation;1800 g a.i. / ha, up to 2 times per year, manual hand-held spray application <strong>of</strong> EC<strong>for</strong>mulation.Enclosed space (industrial) usage;0.05 g a.i. / m 3 , up to 2 times per year, automatic fogging application <strong>of</strong> RTU gas orEC <strong>for</strong>mulation;0.1 g a.i. / m 2 , up to 2 times per year, manual hand-held spray application <strong>of</strong> EC<strong>for</strong>mulation.Indoor and outdoor use on surfaces, cracks, crevices;0.25 g a.i. / m 2 , up to 2 times per year, aerosol application <strong>of</strong> RTU gas.0.3 g a.i. / m 2 , up to 2 times per year, manual spray application <strong>of</strong> RTU liquid.1000 g a.i. / ha, 1 time per year, manual fogging application <strong>of</strong> EC <strong>for</strong>mulation.DDVP strips used in biosecurity fruit fly monitoring programme;Up to 90 DDVP strips placed per operator per day, at upto 0.033 g a.i. / ha.<strong>Substance</strong> exported from New Zealand prior to use.Risks and benefits to <strong>the</strong> environment and human healthERMA New Zealand did not identify any beneficial effects to <strong>the</strong> environment or humanhealth from <strong>the</strong> use <strong>of</strong> dichlorvos.ERMA New Zealand‘s interim evaluation indicates that <strong>the</strong> risks range from negligible tohigh to <strong>the</strong> environment and human health associated <strong>for</strong> use <strong>of</strong> dichlorvos in New Zealand.Dichlorvos reassessment – application Page 8 <strong>of</strong> 436
ERMA New Zealand‘s recommendations include measures that it considers will reduce <strong>the</strong>levels <strong>of</strong> risk to negligible, which include use restrictions or <strong>for</strong> some Use Scenarios,prohibition <strong>of</strong> use <strong>for</strong> that purpose.The risks to consumers exposed to dichlorvos residues in food have not been considered byERMA New Zealand in this reassessment. Dietary exposures and risks are evaluated by <strong>the</strong>New Zealand Food Safety Authority <strong>under</strong> <strong>the</strong> Food Act 1981.ERMA New Zealand has identified alternative products that are based on different activeingredients <strong>for</strong> all <strong>of</strong> <strong>the</strong> label use patterns <strong>of</strong> dichlorvos as an agricultural plant protectionproduct. The alternatives present a range <strong>of</strong> hazard classifications, some <strong>of</strong> lower, some <strong>of</strong>greater hazard than dichlorvos. Hazard assessment is not an indication <strong>of</strong> <strong>the</strong> risk posed by asubstance, since exposure is not taken into account, but can be used as an indicator <strong>of</strong>potential to cause effects.ERMA New Zealand notes that <strong>the</strong> unique combination <strong>of</strong> properties that dichlorvospossesses mean that alternatives <strong>for</strong> direct replacement <strong>for</strong> certain non-agricultural uses arenot readily identifiable.Risks and benefits to society and communitiesERMA New Zealand‘s interim evaluation indicates that:<strong>the</strong> level <strong>of</strong> indirect benefit to public health (i.e. reduction in adverse effectsthrough control <strong>of</strong> pests, such as cockroaches or fleas) through use <strong>of</strong> dichlorvosin large scale facilities, public buildings or public amenity is minimal, and is atleast likely to occur, resulting in a low level <strong>of</strong> positive effect.No potentially significant benefits or positive effects as a result <strong>of</strong> <strong>the</strong>unavailability <strong>of</strong> <strong>the</strong> substances have been identified.Risks and benefits to <strong>the</strong> market economyERMA New Zealand‘s interim evaluation indicates that:<strong>the</strong> overall benefit <strong>of</strong> dichlorvos to <strong>the</strong> horticulture sector, and specifically <strong>the</strong>glasshouse production <strong>of</strong> tomatoes, capsicum and cucumber are at least low;<strong>the</strong> overall benefit <strong>of</strong> dichlorvos <strong>for</strong> countering biosecurity incursions, <strong>the</strong> level <strong>of</strong>benefit on trade has been assessed low to medium;<strong>the</strong> positive effects <strong>of</strong> its use <strong>for</strong> <strong>the</strong> treatment <strong>of</strong> large structures outweigh <strong>the</strong>adverse effects.Relationship <strong>of</strong> Māori to <strong>the</strong> environmentIn preparing this application, ERMA New Zealand has not conducted a specific Māoriconsultation but <strong>the</strong> impression gained from a hui with iwi/Māori resource managers is thatunless substances provide clear benefits to outweigh potential risk, <strong>the</strong>y generally oppose <strong>the</strong>ongoing use <strong>of</strong> hazardous substances. In <strong>the</strong> absence <strong>of</strong> fur<strong>the</strong>r in<strong>for</strong>mation regardingbenefits, it is expected that submissions from Māori would generally seek <strong>the</strong> revocation <strong>of</strong><strong>the</strong> approvals <strong>for</strong> dichlorvos and its <strong>for</strong>mulations.Overall evaluationERMA New Zealand concludes that, with current controls in place, non-negligible risks to <strong>the</strong>environment and human health may be posed.Dichlorvos reassessment – application Page 9 <strong>of</strong> 436
This evaluation takes into account that ERMA New Zealand‘s assessment is based on <strong>the</strong>in<strong>for</strong>mation that is available to it. Additional in<strong>for</strong>mation is welcomed. ERMA New Zealandinvites submitters to provide additional in<strong>for</strong>mation that <strong>the</strong>y might have, and notes <strong>the</strong>following as areas where additional in<strong>for</strong>mation may be particularly useful:<strong>the</strong> level <strong>of</strong> benefit <strong>of</strong>fered by dichlorvos substances, especially regarding socialeffects from <strong>the</strong> use <strong>of</strong> dichlorvos (e.g. effect on local employment opportunities,direct/indirect local community impact arising from dichlorvos use);<strong>the</strong> level <strong>of</strong> ecomonic benefit provided to <strong>the</strong> public health sector by dichlorvos;<strong>the</strong> financial implications <strong>of</strong> overseas restrictions on crops treated with dichlorvos;identification <strong>of</strong> <strong>the</strong> use and availability <strong>of</strong> alternative substances, with particularregard to dichlorvos use in non-agricultural enclosed space use;identification <strong>of</strong> use patterns that have not been included in <strong>the</strong> assessment;provision <strong>of</strong> data to determine when unrestricted entry into treated glasshouses ormushroom houses can occur;identification <strong>of</strong> minimum effective application rates, which may be used to refine<strong>the</strong> exposure assessment;feasibility <strong>of</strong> proposed risk management measures, and <strong>the</strong> implications <strong>of</strong> <strong>the</strong>modified control regime (such as financial implications <strong>of</strong> installing or upgradingapplication equipment).ERMA New Zealand considers that:<strong>the</strong> non-negligible risks to <strong>the</strong> environment (Use Scenarios 1 to 8) cannot bereduced to negligible by <strong>the</strong> application <strong>of</strong> practicable controls to <strong>the</strong> existingapprovals, and that <strong>the</strong>se adverse effects are not outweighed by <strong>the</strong> positiveeffects;<strong>the</strong> non-negligible risks to human health can be reduced to negligible <strong>for</strong> <strong>the</strong> UseScenarios 9 to 29, and 31 by <strong>the</strong> application <strong>of</strong> practicable controls;<strong>the</strong> non-negligible risks to human health cannot be reduced to negligible <strong>for</strong> UseScenario 30 by <strong>the</strong> application <strong>of</strong> practicable controls, and that <strong>the</strong>se adverseeffects are not outweighed by <strong>the</strong> positive effects.ERMA New Zealand considers that <strong>the</strong> Outcome Scenarios in Table ES. 5 are appropriate <strong>for</strong>continued safe use <strong>of</strong> dichlorvos in New Zealand.Table ES. 5Summary <strong>of</strong> proposed Outcome Scenarios <strong>for</strong> use <strong>of</strong> dichlorvos.Use Scenarios Continue Use Restrict Use /Additional ControlsOutdoor agricultural usage1 - 8Enclosed space, agricultural usage9 - 16Enclosed space, industrial usage17 - 25Enclosed space, domestic usageOutcomeScenario (a)OutcomeScenario (b)DiscontinueUseOutcomeScenario (c)Dichlorvos reassessment – application Page 10 <strong>of</strong> 436
26 - 29Outdoor public space usage30Biosecurity use31Manufacture <strong>for</strong> export32Preliminary RecommendationsOn <strong>the</strong> basis <strong>of</strong> its evaluation <strong>of</strong> whe<strong>the</strong>r <strong>the</strong> risks associated with <strong>the</strong> use <strong>of</strong> dichlorvos inNew Zealand outweigh <strong>the</strong> benefits, ERMA New Zealand proposes <strong>the</strong> following preliminaryrecommendations to ensure that practices minimise <strong>the</strong> risk <strong>for</strong> people and <strong>the</strong> environment:Discontinue Use (Outcome Scenario (c)) <strong>for</strong> outdoor agricultural or public area uses.Continue Use (Outcome Scenario (a)) is proposed <strong>for</strong> dichlorvos (approval numberHSR002838).Continue Use (Outcome Scenario (a)) is proposed <strong>for</strong> J72.03 (approval number HSR001757).Restrict Use / Additional Controls (Outcome Scenario (b)) is proposed <strong>for</strong> <strong>the</strong> followingdichlorvos-containing substances:DDVP Insecticide Strip (approval number HSR000126);Flammable aerosol containing 3.1 g/litre dichlorvos and 8.7 g/litre propoxur(approval number HSR000207);Ready to use liquid containing 4.4 g/litre dichlorvos and 9.6 g/litre propoxur(approval number HSR000209);Emulsifiable concentrate containing 1000 g/litre dichlorvos (approval numberHSR000211);Aerosol containing 50 g/kg dichlorvos (approval number HSR000212);Emulsifiable concentrate containing 1140 g/litre dichlorvos (approval numberHSR000213).The proposed variations <strong>for</strong> <strong>the</strong>se approvals are detailed in Table ES. 6.Table ES. 6Summary <strong>of</strong> <strong>the</strong> proposed variations <strong>for</strong> dichlorvos and dichlorvos-containingsubstances.<strong>Substance</strong> detailsHSR002838Dichlorvos[CAS #62-73-7]HSR000126DDVPInsecticide StripUse Scenario31HSR000207FlammableProposed variationsNo variations to existing conditions proposed.1. Use that is not in accordance with <strong>the</strong> label instructions is prohibited;2. Introduce PPE requirements <strong>for</strong> operators;3. Restrict <strong>the</strong> number <strong>of</strong> strips handled / traps serviced by operators per day;4. Labelling requirements to identify <strong>the</strong> inhalation risk;5. Provision <strong>of</strong> guidance material <strong>for</strong> transportation and use <strong>of</strong> DDVP Strips.1. Use that is not in accordance with <strong>the</strong> label instructions is prohibited;2. Restrict use to industrial sites and by commercial applicators only –Dichlorvos reassessment – application Page 11 <strong>of</strong> 436
<strong>Substance</strong> detailsaerosolcontaining 3.1g/litre dichlorvosand 8.7 g/litrepropoxurUse Scenarios26-27HSR000209Ready to useliquid containing4.4 g/litredichlorvos and9.6 g/litrepropoxurUse Scenarios28-29HSR000211Emulsifiableconcentratecontaining 1000g/litre dichlorvosUse Scenarios1-8,11-16,20-25,30HSR000212Aerosolcontaining 50g/kg dichlorvosUse Scenarios9-10, 17-19HSR000213Emulsifiableconcentratecontaining 1140g/litre dichlorvosUse ScenariosProposed variationsapproved handler exemption removed;3. Introduce PPE/RPE requirements;4. <strong>Application</strong> methods to be restricted to remote, automatic deliverysystems;5. Introduce maximum application rates and treatment areas;6. Introduce a restricted entry intervals;7. Introduce a maximum exposure time <strong>for</strong> entry into treated area.1. Use that is not in accordance with <strong>the</strong> label instructions is prohibited;2. Restrict use to industrial sites and by commercial applicators only –approved handler exemption removed;3. Introduce PPE/RPE requirements;4. <strong>Application</strong> methods to be restricted to remote, automatic deliverysystems;5. Introduce maximum application rates and treatment areas;6. Introduce a restricted entry intervals;7. Introduce a maximum exposure time <strong>for</strong> entry into treated area.1. Use that is not in accordance with <strong>the</strong> label instructions is prohibited;2. Outdoor agricultural or public area use is prohibited;3. <strong>Application</strong> methods to be restricted to remote, automatic deliverysystems, or limited manual hand-spraying;4. Apply a maximum quantity that an individual may mix/load per day;5. Introduce maximum application rates;6. Introduce PPE/RPE requirements;7. Introduce a restricted entry intervals;8. Introduce a maximum exposure time <strong>for</strong> entry into treated area.1. Use that is not in accordance with <strong>the</strong> label instructions is prohibited;2. Introduce PPE/RPE requirements <strong>for</strong> connection / disconnection <strong>of</strong>cylinders, and entry into treated areas;3. Restrict number <strong>of</strong> cylinder changes per operator per day;4. Introduce maximum application rates;5. Introduce a maximum daily treatment volume per operator per day <strong>for</strong>manual application;6. Introduce a restricted entry intervals;7. Introduce a maximum exposure times <strong>for</strong> entry into treated area <strong>for</strong>different tasks.1. Use that is not in accordance with <strong>the</strong> label instructions is prohibited;2. Outdoor agricultural or public area use is prohibited;3. <strong>Application</strong> methods to be restricted to remote, automatic deliverysystems, or limited manual hand-spraying;4. Apply a maximum quantity that an individual may mix/load per day;Dichlorvos reassessment – application Page 12 <strong>of</strong> 436
<strong>Substance</strong> details1-8,11-16,20-25,30HSR001757J72.03Use Scenarios32Proposed variations5. Introduce PPE/RPE requirements;6. Introduce maximum application rates;7. Introduce a restricted entry intervals;8. Introduce a maximum exposure time <strong>for</strong> entry into treated area.No variations to existing conditions proposed.ERMA New Zealand proposes that <strong>the</strong>se recommendations are phased-in over a 12 monthperiod.ERMA New Zealand notes that <strong>the</strong> Authority must consider <strong>the</strong> costs and benefits <strong>of</strong> variedor additional controls, in accordance with clause 35 <strong>of</strong> <strong>the</strong> Methodology. If <strong>the</strong>recommendations from this assessment are adopted <strong>the</strong>re may be additional costs required tousers arising from a need to upgrade existing or install new equipment in order to continue touse dichlorvos <strong>for</strong> certain uses. The net level <strong>of</strong> benefit may be reduced as a result. ERMANew Zealand invites submitters to provide in<strong>for</strong>mation relating to <strong>the</strong> cost implications <strong>of</strong>adopting <strong>the</strong> proposed recommendations.Finally, if <strong>the</strong> Authority‘s overall evaluation favours retention <strong>of</strong> some or all <strong>of</strong> <strong>the</strong> dichlorvosapprovals, ERMA New Zealand proposes <strong>the</strong> revised classifications <strong>for</strong> dichlorvos anddichlorvos-containing substances detailed in Table ES. 3.SubmissionsSubmissions are now invited on <strong>the</strong> appropriateness or workability <strong>of</strong> <strong>the</strong> aboverecommendations.Submissions on this application must be made within a 40 working day period. Electronicresponses using <strong>the</strong> <strong>for</strong>m on our web site are encouraged. Please return your submission,whe<strong>the</strong>r electronic or by post, fax or email to:ERMA New ZealandPO Box 131WellingtonFax: 04 914 0433Email: reassessments@ermanz.govt.nzwww.ermanz.govt.nzAll submissions must be received by 5 pm, 18 February 2011.Submissions must state <strong>the</strong> reasons <strong>for</strong> making <strong>the</strong> submission and state whe<strong>the</strong>r <strong>the</strong> submitterwishes to be heard at a public hearing. The submission may also state any decision sought.For more in<strong>for</strong>mation on <strong>the</strong> reassessment process seehttp://www.ermanz.govt.nz/hs/reassessment/index.html .Dichlorvos reassessment – application Page 13 <strong>of</strong> 436
SECTION 1 – THE APPLICATION1.1 Applicant details1.1.1 Name and address in New Zealand <strong>of</strong> <strong>the</strong> organisation making <strong>the</strong> applicationName:Chief ExecutiveERMA New ZealandPostal Address: P O Box 131Wellington 6140New ZealandPhysical address: Level 1BP House20 Customhouse QuayWellingtonNew ZealandPhone: +64-4-916 2426Fax: +64-4-914 04331.1.2 Name <strong>of</strong> <strong>the</strong> contact person <strong>for</strong> <strong>the</strong> applicationName:Position:Postal address:Mat<strong>the</strong>w AllenAdvisor (<strong>Hazardous</strong> <strong>Substance</strong>s)ERMA New ZealandPO Box 131Wellington 6140New ZealandPhone: 04 918 4803Email:mat<strong>the</strong>w.allen@ermanz.govt.nz1.2 Background to <strong>the</strong> application1.2.1 This is an application <strong>for</strong> <strong>the</strong> reassessment <strong>of</strong> dichlorvos and <strong>for</strong>mulations containingdichlorvos prepared by ERMA New Zealand <strong>under</strong> section 63 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong><strong>Substance</strong>s and New Organisms Act (‗<strong>the</strong> Act‘).1.2.2 Dichlorvos was placed on <strong>the</strong> Chief Executive‘s <strong>Reassessment</strong> (CEIR) Priority Listin 2007, taking into account:Dichlorvos has high acute toxicity via oral, dermal and inhalation routes andhas <strong>the</strong> potential to cause adverse effects to <strong>the</strong> nervous system in humans atlow concentrations.Dichlorvos is also very ecotoxic to aquatic organisms, birds and honeybees.The US imposed a series <strong>of</strong> new and more stringent measures to mitigate <strong>the</strong>residential, occupational and ecological risks <strong>of</strong> dichlorvosSubmissions on <strong>the</strong> consultation <strong>of</strong> <strong>the</strong> proposed substances indicated thatdichlorvos should be on <strong>the</strong> CEIR priority list.Dichlorvos reassessment – application Page 14 <strong>of</strong> 436
1.2.3 In 2008, <strong>the</strong> Environmental Risk Management Authority (‗<strong>the</strong> Authority‘) consideredwhe<strong>the</strong>r or not <strong>the</strong>re were grounds <strong>for</strong> reassessing <strong>the</strong> approvals <strong>for</strong> dichlorvos and<strong>for</strong>mulations containing dichlorvos, <strong>under</strong> section 62 <strong>of</strong> <strong>the</strong> Act.1.2.4 The Authority decided that <strong>the</strong>re were grounds <strong>for</strong> reassessment <strong>of</strong> dichlorvos and its<strong>for</strong>mulations, based on sections 62 <strong>of</strong> <strong>the</strong> Act, namely that: <strong>the</strong>re is new in<strong>for</strong>mationfrom overseas regulatory authorities relating to <strong>the</strong> effects <strong>of</strong> dichlorvos and its<strong>for</strong>mulations and that, in light <strong>of</strong> this new in<strong>for</strong>mation, reassessment <strong>of</strong> <strong>the</strong> substanceis warranted.1.2.5 The Authority considered that a reassessment <strong>of</strong> dichlorvos and its <strong>for</strong>mulationsaligns well with ERMA New Zealand‘s risk reduction strategy, which seeks toreduce <strong>the</strong> risks New Zealanders may be exposed to via new organisms or hazardoussubstances.1.2.6 The decision that grounds <strong>for</strong> <strong>the</strong> reassessment <strong>of</strong> dichlorvos and its <strong>for</strong>mulations hadbeen established was notified on 04 September 2008. In reaching its decision <strong>the</strong>Authority noted <strong>the</strong> following:Formulations containing dichlorvos have been registered <strong>for</strong> use in NewZealand since 1968. Currently, four products are registered <strong>for</strong> agricultural usein New Zealand (ArmourCrop-Insecticide (DDVP), DDVP Insecticide Strip,Divap, Nuvos);O<strong>the</strong>r dichlorvos-containing products are available: BV2 Surface Insecticide,BV2 Surface Insecticide Bulk, Insectigas;J72.03 is manufactured <strong>for</strong> export;Overseas regulatory action has led to <strong>the</strong> withdrawal/phasing out <strong>of</strong> dichlorvosin Europe (and certain products in North America), <strong>the</strong> adoption <strong>of</strong> morestringent measures <strong>for</strong> domestic and agricultural use in <strong>the</strong> USA and Canada,and a proposal <strong>for</strong> adoption <strong>of</strong> more stringent measures in Australia.The reassessment <strong>of</strong> dichlorvos and its <strong>for</strong>mulations aligns with <strong>the</strong> principles<strong>of</strong> <strong>the</strong> ERMA New Zealand Risk Reduction strategy.1.3 Preparation <strong>of</strong> <strong>the</strong> application1.3.1 In preparing this application, ERMA New Zealand sought in<strong>for</strong>mation fromimporters and users regarding:use patterns including ‗<strong>of</strong>f label‘ uses;benefits from <strong>the</strong> use <strong>of</strong> <strong>the</strong> substance in New Zealand; andlifecycle in<strong>for</strong>mation.1.3.2 A full list <strong>of</strong> <strong>the</strong> parties contacted <strong>for</strong> this in<strong>for</strong>mation is set out in Appendix M.1.3.3 In response to this pre-application consultation, in<strong>for</strong>mation was received from:Adria Crop Protection (Len Stulich)Auckland Regional Council (Sandi Murray)BOCEcolab (Eric Van Essen)Environment Bay <strong>of</strong> Plenty (David Phizacklea)Environment Canterbury (Ron McCraw)Fonterra (Roger Andela)Dichlorvos reassessment – application Page 15 <strong>of</strong> 436
Foundation <strong>for</strong> Arable Research (Nick Pyke)Greater Wellington (Ray Clarey)Horticulture New ZealandMAF Biosecurity (Vivien Thompson)Meadow Mushrooms Ltd (Gill Hoglund)Nor<strong>the</strong>rn Distributors (Les Bryant)Northland Cymbidium Grower‘s AssociationOrion Crop Protection (John Hicking)Rentokil (Jon Thompson)1.3.4 New Zealand Food Safety Authority (NZFSA) supplied a document (Appendix M)outlining <strong>the</strong> responsibilities <strong>of</strong> NZFSA <strong>under</strong> <strong>the</strong> various legislations relevant topesticide regulation.1.3.5 ERMA New Zealand also commissioned a report from Plant & Food Research(Appendix R) regarding:Horticultural use patterns including ‗<strong>of</strong>f label‘ uses;benefits from <strong>the</strong> use <strong>of</strong> <strong>the</strong> substance in New Zealand;lifecycle in<strong>for</strong>mation; andavailability <strong>of</strong> alternative pesticides.1.3.6 To <strong>the</strong> extent appropriate, ERMA New Zealand considered publicly availablesources <strong>of</strong> toxicology and environmental fate and effects test data.1.4 Notification and Consultation1.4.1 This application has been prepared by ERMA New Zealand and will be publiclynotified <strong>for</strong> submissions <strong>for</strong> a 40 working day period. The submissions received,toge<strong>the</strong>r with <strong>the</strong> application, will be taken into account by <strong>the</strong> Authority inconsidering <strong>the</strong> reassessment. If required by any submitter, <strong>the</strong> Authority will hold apublic hearing.1.4.2 ERMA New Zealand also commissioned a report from Martin Edwards Consultingregarding:<strong>the</strong> toxicology <strong>of</strong> dichlorvos; andexposure <strong>of</strong> operators and bystanders.1.4.3 <strong>Substance</strong>(s) covered by <strong>the</strong> application1.4.4 Existing dichlorvos-containing substances <strong>for</strong> which <strong>the</strong>re are HSNO approvals andwhich are <strong>the</strong>re<strong>for</strong>e <strong>the</strong> subject <strong>of</strong> this reassessment, are shown in Table 1:Dichlorvos reassessment – application Page 16 <strong>of</strong> 436
Table 1. Dichlorvos-containing substances covered by this application 1 .<strong>Substance</strong> description Approval # Trade namesDichlorvos [CAS #62-73-7] HSR002838 No trade names <strong>for</strong> thisapproval.Aerosol containing 50 g/kg dichlorvos HSR000212 Insectigas / ArmourCrop-Insecticide*Emulsifiable concentrate containing1000 g/litre dichlorvosEmulsifiable concentrate containing1140 g/litre dichlorvosFlammable aerosol containing 3.1g/litre dichlorvos and 8.7 g/litrepropoxurReady to use liquid containing 4.4g/litre dichlorvos and 9.6 g/litrepropoxurDDVP Insecticide Strip [intended <strong>for</strong>use in fly monitoring]HSR000211HSR000213HSR000207HSR000209HSR000126Nuvos*Divap*BV2 Surface InsecticideBV2 Surface InsecticideBulkDDVP Insecticide Strip*J72.03 [insecticide <strong>for</strong> export-only] HSR001757 No trade names <strong>for</strong> thisapproval.* Currently (22 November 2010) registered <strong>under</strong> <strong>the</strong> Agricultural Compounds and Veterinary Medicines (ACVM)Act. BV2 Surface Insecticides are only used in domestic settings and do not require ACVM registration.Dichlorvos reassessment – application Page 17 <strong>of</strong> 436
SECTION 2 - THE RISK MANAGEMENT CONTEXT2.1 Risk management context2.1.1 The Authority decides whe<strong>the</strong>r to approve or decline hazardous substances based on<strong>the</strong> requirements <strong>of</strong> <strong>the</strong> HSNO Act and <strong>the</strong> Methodology 1 . The purpose <strong>of</strong> <strong>the</strong> Act isto ―protect <strong>the</strong> environment and <strong>the</strong> health and safety <strong>of</strong> people and communities, bypreventing or managing <strong>the</strong> adverse effects <strong>of</strong> hazardous substances and neworganisms‖. The Act and <strong>the</strong> Methodology <strong>the</strong>re<strong>for</strong>e provide <strong>the</strong> foundation <strong>for</strong> <strong>the</strong>risk management context <strong>for</strong> <strong>the</strong> evaluation and review <strong>of</strong> this application whichmust be <strong>under</strong>taken in accordance with <strong>the</strong> purpose <strong>of</strong> <strong>the</strong> Act.2.1.2 Section 29 <strong>of</strong> <strong>the</strong> Act requires <strong>the</strong> Authority to consider adverse and positive effects<strong>of</strong> <strong>the</strong> substance(s) and to make a decision based on whe<strong>the</strong>r or not <strong>the</strong> positiveeffects <strong>of</strong> releasing <strong>the</strong> substance outweigh <strong>the</strong> adverse effects <strong>of</strong> <strong>the</strong> substance. Therelevant adverse and positive effects are those that are associated with <strong>the</strong> substance.2.1.3 In particular, in accordance with section 6 <strong>of</strong> <strong>the</strong> Act, <strong>the</strong> following matters havebeen taken into account in assessing <strong>the</strong> risks, costs and benefits associated with <strong>the</strong>use <strong>of</strong> dichlorvos in New Zealand:The sustainability <strong>of</strong> native and valued introduced flora and fauna;The intrinsic value <strong>of</strong> ecosystems;Public health;The relationship <strong>of</strong> Māori and <strong>the</strong>ir culture and traditions with <strong>the</strong>ir ancestrallands, water, sites, wāhi tapu, valued flora and fauna, and o<strong>the</strong>r taonga;The economic and related benefits to be derived from <strong>the</strong> use <strong>of</strong> dichlorvos;New Zealand‘s international obligations.2.1.4 ERMA New Zealand notes that comparison <strong>of</strong> risks or benefits, <strong>for</strong> example a risk <strong>of</strong>chronic human toxic effects compared to a risk <strong>of</strong> aquatic toxic effects, and <strong>the</strong>comparison <strong>of</strong> risks and benefits, <strong>for</strong> example an environmental or human health riskcompared to a societal or economic benefit, requires value judgement. This is takeninto account in making recommendations (Section 7) and <strong>the</strong> Authority will take thisinto account in reaching an overall assessment <strong>of</strong> <strong>the</strong> risks and benefits.2.2 Consideration <strong>of</strong> Outcome Scenarios2.2.1 Risk-benefit analysis is used to assess <strong>the</strong> adverse and positive effects. Risk-benefitanalysis is a comparative tool; thus <strong>the</strong> results <strong>of</strong> <strong>the</strong> assessment <strong>of</strong> risks and benefits<strong>for</strong> one option need to be compared against one or more alternative options.2.2.2 In <strong>the</strong> HSNO context <strong>the</strong>re are two basic options in terms <strong>of</strong> <strong>the</strong> resultant riskmanagement regimes to be applied to <strong>the</strong> approvals <strong>for</strong> substances containingdichlorvos: <strong>the</strong> baseline Outcome Scenario linked to <strong>the</strong> status quo and one or morealternative Outcome Scenarios. In this instance <strong>the</strong> baseline scenario is based on <strong>the</strong>current use <strong>of</strong> <strong>the</strong> substance.2.2.3 Dichlorvos is used in a range <strong>of</strong> sectors. The sectors evaluated in this applicationare: dispersive use, greenhouse use, use on industrial premises, use in domestic and1<strong>Hazardous</strong> <strong>Substance</strong>s and New Organisms (Methodology) Order 1998 (SR 1998/217).Dichlorvos reassessment – application Page 18 <strong>of</strong> 436
public environments and use <strong>for</strong> biosecurity purposes. For each sector use <strong>of</strong>dichlorvos, ERMA New Zealand considered <strong>the</strong> following Outcome Scenarios:(a) The baseline scenario: continued use with <strong>the</strong> current controls;(b) Continued use with revised controls;(c) Prohibition <strong>of</strong> use.2.2.4 The assessment <strong>of</strong> effects is based on <strong>the</strong> difference between Outcome Scenario (b)and <strong>the</strong> baseline, and Outcome Scenario (c) and <strong>the</strong> baseline. The assessmentassumes that <strong>the</strong> existing controls will be complied with and thus <strong>the</strong> relevant risksare those that remain after <strong>the</strong> controls are taken into account.2.2.5 The first step in <strong>the</strong> reassessment is to determine whe<strong>the</strong>r or not <strong>the</strong>re are anypotentially significant adverse effects. If <strong>the</strong> adverse effects are negligible, <strong>the</strong>nfur<strong>the</strong>r analysis is not required (i.e. Outcome Scenario (a)). However, if <strong>the</strong>re arepotentially significant adverse effects <strong>the</strong>n additional controls may be applied toameliorate <strong>the</strong>se adverse effects. The application <strong>of</strong> additional controls andrestrictions on <strong>the</strong> current use <strong>of</strong> dichlorvos is treated as a modification <strong>of</strong> <strong>the</strong>baseline scenario (i.e. Outcome Scenario (b)). If no practical controls or restrictionscan adequately ameliorate <strong>the</strong>se adverse effects, <strong>the</strong>n that use may be prohibited (i.e.Outcome Scenario (c)).2.3 Identification and assessment process2.3.1 ERMA New Zealand identified <strong>the</strong> risks and benefits associated with <strong>the</strong> substanceand <strong>the</strong>n <strong>under</strong>took a scoping exercise to determine which <strong>of</strong> <strong>the</strong>m are potentiallysignificant. Risks and benefits are identified in terms <strong>of</strong> <strong>the</strong> scenarios and thisrequires identifying <strong>the</strong> sources <strong>of</strong> effect (<strong>for</strong> example, <strong>the</strong> hazards and benefits), <strong>the</strong>pathways <strong>for</strong> exposure, <strong>the</strong> areas <strong>of</strong> impact, and <strong>the</strong> likelihood and magnitude <strong>of</strong>effect. In accordance with clauses 9 and 10 <strong>of</strong> <strong>the</strong> Methodology, and sections 5 and6 <strong>of</strong> <strong>the</strong> Act, <strong>the</strong> risks and benefits are characterised in relation to <strong>the</strong> following areas<strong>of</strong> impact: <strong>the</strong> environment, human health and safety, relationship <strong>of</strong> Māori to <strong>the</strong>environment, <strong>the</strong> market economy, and society and <strong>the</strong> community.2.3.2 The second step is to assess <strong>the</strong> risks and benefits that have been identified as beingpotentially significant. Those risks and benefits that are deemed to be not potentiallysignificant are described, but are not assessed in detail. Assessing risks and benefitsinvolves combining <strong>the</strong> magnitude (size or value) <strong>of</strong> an effect and <strong>the</strong> likelihood <strong>of</strong> itoccurring. Where <strong>the</strong>re is uncertainty about <strong>the</strong> magnitude <strong>of</strong> <strong>the</strong> effect a range <strong>of</strong>magnitudes may be assessed.2.3.3 The estimation <strong>of</strong> magnitude and likelihood is conducted on a qualitative basisin<strong>for</strong>med where possible by quantitative estimates and analysis.2.3.4 The approach adopted in identifying and assessing risks and benefits (adverse andpositive effects) is as described in <strong>the</strong> ERMA New Zealand technical guides:Assessment <strong>of</strong> Effects <strong>of</strong> <strong>Hazardous</strong> <strong>Substance</strong>s and New Organisms onHuman Health (ERMA New Zealand 2000);Decision Making: A Technical Guide to Identifying, Assessing and EvaluatingRisks, Costs and Benefits (ERMA New Zealand 2009); andAssessment <strong>of</strong> Economic Risks, Costs and Benefits: consideration <strong>of</strong> impactson <strong>the</strong> market economy (ERMA New Zealand 2005).Dichlorvos reassessment – application Page 19 <strong>of</strong> 436
2.3.5 Details <strong>of</strong> ERMA New Zealand‘s qualitative risk assessment methodology are set outin Appendix H.2.4 Consideration <strong>of</strong> uncertainty2.4.1 Clause 8 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s and New Organisms (Methodology) Order1998 (<strong>the</strong> Methodology) states that <strong>the</strong> in<strong>for</strong>mation used by <strong>the</strong> Authority whenconsidering an application must be relevant and appropriate to <strong>the</strong> scale andsignificance <strong>of</strong> <strong>the</strong> risks, costs and benefits associated with <strong>the</strong> substance.2.4.2 Clause 29 <strong>of</strong> <strong>the</strong> Methodology indicates that when <strong>the</strong> Authority encounters scientificand technical uncertainty relating to <strong>the</strong> potential adverse effects <strong>of</strong> a substance, <strong>the</strong>Authority must determine <strong>the</strong> materiality and significance to <strong>the</strong> application <strong>of</strong> <strong>the</strong>uncertainty. Where any scientific or technical uncertainty is not resolved, <strong>the</strong>Authority must take into account <strong>the</strong> need <strong>for</strong> caution in managing <strong>the</strong> adverseeffects <strong>of</strong> <strong>the</strong> substance (clause 30).2.4.3 Where <strong>the</strong> Authority considers that <strong>the</strong>re is uncertainty in relation to costs, benefits,and risks (including, where applicable, <strong>the</strong> scope <strong>for</strong> managing those risks), <strong>the</strong>Authority must attempt to establish <strong>the</strong> range <strong>of</strong> uncertainty and must take intoaccount <strong>the</strong> probability <strong>of</strong> <strong>the</strong> costs, benefits and risks being ei<strong>the</strong>r more or less than<strong>the</strong> levels presented in evidence (clause 32).2.5 Ethical considerations2.5.1 In reviewing <strong>the</strong> in<strong>for</strong>mation provided and identifying and assessing <strong>the</strong> adverse andpositive effects <strong>of</strong> dichlorvos, ethical matters relevant to <strong>the</strong> use <strong>of</strong> dichlorvos havebeen taken into account. Guidance is provided by <strong>the</strong> ERMA New Zealand EthicsFramework Protocol. 2 This framework acknowledges that individuals andcommunities hold a range <strong>of</strong> ethical views. It has been developed as a tool to assistall participants in <strong>the</strong> ERMA New Zealand decision-making process to:ask <strong>the</strong> ‗right‘ questions in order to identify areas where <strong>the</strong>re are ethicalmatters to be considered; anduse <strong>the</strong> answers to <strong>the</strong>se questions to explore whe<strong>the</strong>r and how ethicalconsiderations need to be addressed.2.5.2 The foundation <strong>of</strong> <strong>the</strong> framework is a set <strong>of</strong> ethical principles, supported byprocedural standards. The two general principles, which are embodied in <strong>the</strong> HSNOAct and <strong>the</strong> Methodology, are:respect <strong>for</strong> <strong>the</strong> environment; andrespect <strong>for</strong> people (including past, present and future generations).2.5.3 Under <strong>the</strong>se general principles is a set <strong>of</strong> specific principles expressed as concerns.These are concern <strong>for</strong> animal welfare, autonomy, co-operation, culturalidentity/pluralism, human rights, human dignity, justice and equality, sustainabilityand wellbeing/non-harm.2.5.4 The primary mechanisms <strong>for</strong> supporting <strong>the</strong> principles outlined in <strong>the</strong> framework and<strong>for</strong> evaluating whe<strong>the</strong>r or not <strong>the</strong>y are upheld are <strong>the</strong> procedural standards <strong>of</strong> honestyand integrity, transparency and openness, a sound methodology, community andexpert consultation and a fair decision-making process.2.5.5 In preparing this application ERMA New Zealand has applied <strong>the</strong> criteria in <strong>the</strong>procedural standards listed above to its evaluation and review <strong>of</strong> all <strong>the</strong> in<strong>for</strong>mation2December 2005, ER-PR-05-1 12/05.Dichlorvos reassessment – application Page 20 <strong>of</strong> 436
available to it. In preparing this application, ERMA New Zealand has beenconscious <strong>of</strong> <strong>the</strong> concerns expressed by parties who have supplied in<strong>for</strong>mation toassist in <strong>the</strong> preparation <strong>of</strong> this application, and <strong>the</strong>ir beliefs that are <strong>the</strong> basis <strong>for</strong><strong>the</strong>se concerns. When ethical dilemmas arise ERMA New Zealand has described<strong>the</strong>m in terms <strong>of</strong> <strong>the</strong> framework.2.6 Principles <strong>of</strong> <strong>the</strong> Treaty <strong>of</strong> Waitangi (Te Tiriti ō Waitangi)2.6.1 Section 8 <strong>of</strong> <strong>the</strong> Act requires <strong>the</strong> Authority, when considering applications, to takeinto account <strong>the</strong> principles <strong>of</strong> <strong>the</strong> Treaty <strong>of</strong> Waitangi. Of particular relevance to thisapplication is <strong>the</strong> principle <strong>of</strong> active protection affirmed in 1987 by <strong>the</strong> Court <strong>of</strong>Appeal in <strong>the</strong> Lands case.2.6.2 It refers to <strong>the</strong> Crown‘s obligation to take positive steps to ensure that Māori interestsare protected, and to consider <strong>the</strong>m in line with <strong>the</strong> interests guaranteed to Māori inArticle II <strong>of</strong> <strong>the</strong> Treaty. Specifically <strong>the</strong> Court noted that ―… <strong>the</strong> duty <strong>of</strong> <strong>the</strong> Crown isnot merely passive but extends to active protection <strong>of</strong> Māori people in <strong>the</strong> use <strong>of</strong> <strong>the</strong>irlands and waters to <strong>the</strong> fullest extent practicable‖ (Cooke 1987).2.6.3 Taking into account <strong>the</strong> principle <strong>of</strong> active protection requires this application toprovide sufficient evidence to show that <strong>the</strong> use <strong>of</strong> dichlorvos poses no risk <strong>of</strong>adverse effects to native/endemic species and/or o<strong>the</strong>r taonga species, ecosystemsand traditional Māori values, practices, health and well-being. In considering <strong>the</strong>level <strong>of</strong> uncertainty described in relation to <strong>the</strong> adverse effects noted above, ERMANew Zealand considers that this application may currently be viewed as beinginconsistent with <strong>the</strong> principle <strong>of</strong> active protection.Dichlorvos reassessment – application Page 21 <strong>of</strong> 436
SECTION 3– THE SUBSTANCE AND ITS LIFECYCLE3.1 Identification <strong>of</strong> <strong>the</strong> substanceTable 2.Identity <strong>of</strong> dichlorvos.Summary In<strong>for</strong>mation dichlorvosActive substance (ISO Common Name)O<strong>the</strong>r common namesFunctionChemical name (IUPAC)DichlorvosDDVPinsecticide2,2-Dichlorovinyl dimethyl phosphateCAS No 62-73-73.1.1 Dichlorvos is sold as an aerosol in quantities <strong>of</strong> 6 and 36 kg with CO 2 propellant tobe used <strong>for</strong> <strong>the</strong> treatment <strong>of</strong> greenhouses, farm buildings and o<strong>the</strong>r enclosed spaces.It is also sold on <strong>the</strong> domestic market in aerosols containing 3.1 g <strong>of</strong> dichlorvos, co<strong>for</strong>mulatedwith propoxur and isopropyl alcohol as <strong>the</strong> propellant.3.1.2 Dichlorvos is sold as an emulsifiable concentrate containing 1000 or 1140 gdichlorvos/litre in 1 and 5 litre containers. It is sprayed outdoors and indoors and isused in fogging equipment <strong>for</strong> use in enclosed spaces and <strong>for</strong> public healthapplications. Dichlorvos is also sold on <strong>the</strong> domestic market as a ready-to-use liquidcontaining 4.4 g/litre dichlorvos and 9.6 g/litre propoxur.3.1.3 DDVP Insecticide Strip is a solid blue-coloured flexible PVC strip weighing 2.6 g,with dimensions <strong>of</strong> 25 x 15 x 5 mm. Each strip contains 0.48-0.52 g dichlorvos. Thestrips are used by Biosecurity New Zealand as part <strong>of</strong> <strong>the</strong>ir fruit fly surveillanceprogramme.3.2 Regulatory History in New Zealand3.2.1 Dichlorvos (active ingredient) was transferred to <strong>the</strong> HSNO Act in <strong>the</strong> ChemicalsTransfer Notice (01 July 2006).3.2.2 Five <strong>for</strong>mulations containing dichlorvos were transferred to <strong>the</strong> HSNO Act in 2006.These were (toge<strong>the</strong>r with <strong>the</strong>ir HSNO approval numbers): Aerosol containing 50g/kg dichlorvos, HSR000212; Emulsifiable concentrate containing 1000 g/litredichlorvos , HSR000211; Emulsifiable concentrate containing 1140 g/litredichlorvos, HSR000213; Flammable aerosol containing 3.1 g/litre dichlorvos and 8.7g/litre propoxur, HSR000207; Ready to use liquid containing 4.4 g/litre dichlorvosand 9.6 g/litre propoxur, HSR000209.3.2.3 Two products containing dichlorvos have been approved individually <strong>under</strong> <strong>the</strong>HSNO Act, DDVP Insecticide Strip (Approval HSR000126), and J72.03(HSR001757), <strong>the</strong> latter <strong>for</strong> export only.3.2.4 Currently (13 Jan 2010) four products containing dichlorvos are registered <strong>under</strong> <strong>the</strong>Agricultural Compounds and Veterinary Medicines (ACVM) Act (Table 1). Twoproducts (BV2 Suface Insecticide and BV2 Surface Insecticide Bulk) do not requireACVM registrations.Dichlorvos reassessment – application Page 22 <strong>of</strong> 436
3.3 International regulatory position3.3.1 In recent years, dichlorvos has been subject to review in Australia (APVMA), <strong>the</strong>USA (US EPA), Canada (PMRA) and Europe (EU). Details <strong>of</strong> <strong>the</strong>se reviews arecontained in Appendix K and are summarised below.3.3.2 The APVMA (2008) is proposing to restrict <strong>the</strong> use <strong>of</strong> dichlorvos. Remaining usesare those in which exposure <strong>of</strong> operators and bystanders is minimised ei<strong>the</strong>r byautomatic application to enclosed spaces or use <strong>of</strong> small volumes, <strong>for</strong> example <strong>for</strong>treatment <strong>of</strong> wasp nests. In ei<strong>the</strong>r case a minimum <strong>of</strong> elbow length butyl rubbergloves and chemical resistant clothing and in many applications a respirator isprescribed. Restricted entry intervals <strong>of</strong> 96 hours (4 days) <strong>for</strong> enclosed spaces or 4hours <strong>for</strong> glasshouses are prescribed. Indoor domestic use is not expected given<strong>the</strong>se restrictions. Currently <strong>the</strong> only application involving field crops in Australia is<strong>for</strong> avocados, but <strong>the</strong> APVMA proposed that broadacre application to this cropshould be discontinued. Veterinary treatment <strong>of</strong> horses using adichlorvos/oxibendazole paste is supported.3.3.3 In <strong>the</strong> USA dichlorvos is registered to control insect pests in agricultural sites,commercial, institutional and industrial sites; in and around homes; and on pets. It isalso used in greenhouses; mushroom houses; storage areas <strong>for</strong> bulk, packaged andbagged raw and processed agricultural commodities; food manufacturing/processingplants; animal premises; and non-food areas <strong>of</strong> food-handling establishments. It isalso registered <strong>for</strong> direct dermal pour-on treatment <strong>of</strong> cattle, and treatment <strong>of</strong> poultryhouses. It is not registered <strong>for</strong> direct use on any field grown commodities. Shortlyprior to completion <strong>of</strong> <strong>the</strong> USEPA (2006) review, <strong>the</strong> registrants withdrew use <strong>of</strong>hand-held foggers in mushroom houses, greenhouses and warehouses, addedcoveralls to <strong>the</strong> required PPE <strong>for</strong> mushroom house hose-end sprayers and setrestricted entry intervals <strong>of</strong> 24 hours, reducible to 18 hours in mushroom houses and12 hours in greenhouses, if residual concentrations were demonstrated to have fallenbelow specified concentrations. Labelling <strong>of</strong> pest strips was also to be amended to<strong>the</strong> effect that <strong>the</strong>y should only be used in areas occupied <strong>for</strong> < 4 hours / day and <strong>for</strong>agricultural commodities. All o<strong>the</strong>r uses were retained (USEPA, 2006).3.3.4 In Canada, interim measures similar to <strong>the</strong> changes implemented in USEPA (2006)have been introduced (PMRA, 2008).3.3.5 Dichlorvos is not registered <strong>for</strong> use as a plant protection product in Europe. Prior toits removal from Annex 1, its use was supported only on flower bulbs (EU, 2007).Dichlorvos use as a biocide is <strong>under</strong> review <strong>under</strong> <strong>the</strong> Biocides Directive.3.4 Mode <strong>of</strong> action3.4.1 Dichlorvos is an acetylcholinesterase inhibitor active through inhalation, contact andoral exposure.3.5 Review <strong>of</strong> hazardous properties3.5.1 The physico-chemical properties <strong>of</strong> dichlorvos and its <strong>for</strong>mulations are described inAppendix A.3.5.2 The toxicology <strong>of</strong> dichlorvos is summarised in Appendix G.3.5.3 Dichlorvos is <strong>of</strong> high acute toxicity by oral, dermal and inhalation routes <strong>of</strong>exposure. It is an eye and skin irritant and contact sensitiser. Of <strong>the</strong> chronic toxicityclassifications, dichlorvos attracts 6.6B (suspected human or known animalmutagen), 6.7B (suspected human or known or presumed animal carcinogen) and6.9A target organ toxicant, on account <strong>of</strong> its effects by single exposure <strong>for</strong> oral,Dichlorvos reassessment – application Page 23 <strong>of</strong> 436
dermal and inhalation exposure and by oral and inhalation repeat exposure. Primaryeffects are on cholinesterase activity (in <strong>the</strong> blood (plasma and red blood cells) andbrain), and as a result is neurotoxic.3.5.4 Dichlorvos in soil will degrade rapidly, primarily to desmethyldichlorvos anddichloroacetaldehyde, with some dichloroethanol and dichloracetic acid. Both parentand metabolites have half-lives generally
3.6 Classification3.6.1 The HSNO classifications <strong>of</strong> dichlorvos are shown in Table 3 and <strong>the</strong> classifications<strong>of</strong> its <strong>for</strong>mulations is shown in Table 4. The data on which <strong>the</strong>se classifications arebased are shown in Appendices E & G. The data from which <strong>the</strong> classifications <strong>of</strong><strong>the</strong> <strong>for</strong>mulations has been derived is shown in <strong>the</strong> Confidential Appendix. Proposedchanges to <strong>the</strong> existing classifications are highlighted in shaded cells.Table 3.Hazard Class/SubclassClassification <strong>of</strong> dichlorvos.Dichlorvos classificationsExistingProposedClass 1 Explosiveness No NoClass 2, 3 & 4 Flammability No NoClass 5 Oxidisers/Organic Peroxides No NoSubclass 8.1 Metallic corrosiveness No NoSubclass 6.1 Acute toxicity (oral) 6.1B 6.1BSubclass 6.1Acute toxicity (dermal) 6.1B 6.1BSubclass 6.1 Acute toxicity (inhalation) 6.1A 6.1BSubclass 6.3/8.2 Skin irritancy/corrosion ND 6.3BSubclass 6.4/8.3 Eye irritancy/corrosion 6.4A 6.4ASubclass 6.5A Respiratory sensitisation ND NDSubclass 6.5B Contact sensitisation 6.5B 6.5BSubclass 6.6 Mutagenicity No 6.6BSubclass 6.7 Carcinogenicity 6.7B 6.7BSubclass 6.8 Reproductive/ developmentaltoxicitySubclass 6.9 Target organ systemic toxicity(oral: single, repeat)Subclass 6.9 Target organ systemic toxicity(dermal: single)Subclass 6.9 Target organ systemic toxicity(inhalation: single, repeat)NoNo6.9A 6.9A6.9B 6.9B6.9A 6.9ASubclass 9.1 Aquatic ecotoxicity 9.1A 9.1ASubclass 9.2 Soil ecotoxicity ND 9.2DSubclass 9.3 Terrestrial vertebrate ecotoxicity 9.3A 9.3ASubclass 9.4 Terrestrial invertebrate ecotoxicity 9.4A 9.4ADichlorvos reassessment – application Page 25 <strong>of</strong> 436
Table 4.Classification <strong>of</strong> dichlorvos-containing substances.Hazard Class /SubclassClassificationsReady to use liquidcontaining 4.4 g/ldichlorvos & 9.6 g/lpropoxurEmulsifiableconcentratecontaining 1000 g/ldichlorvosAerosol containing50 g/kg dichlorvosEmulsifiableconcentratecontaining 1140g/l dichlorvosFlammableaerosolcontaining 3.1 g/ldichlorvos and8.7 g/l propoxurDDVP insecticidestripJ72.03Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing ProposedClass 1ExplosivenessClass 2, 3 & 4FlammabilityClass 5Oxidisers/OrganicPeroxidesSubclass 8.1MetalliccorrosivenessSubclass 6.1Acute toxicity(oral)No No No No No No NoNo No No 2.1.2A No No NoNo No No No No No NoNo No No No No No No6.1D 6.1B 6.1C N/A, aerosol 6.1B 6.1C N/A, aerosol 6.1D* 6.1B 6.1CSubclass6.1Acutetoxicity(dermal)6.1E 6.1B N/A,aerosol6.1D 6.1B N/A,aerosolNo 6.1E* 6.1CDichlorvos reassessment – application Page 26 <strong>of</strong> 436
Hazard Class /SubclassClassificationsReady to use liquidcontaining 4.4 g/ldichlorvos & 9.6 g/lpropoxurEmulsifiableconcentratecontaining 1000 g/ldichlorvosAerosol containing50 g/kg dichlorvosEmulsifiableconcentratecontaining 1140g/l dichlorvosFlammableaerosolcontaining 3.1 g/ldichlorvos and8.7 g/l propoxurDDVP insecticidestripJ72.03Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing ProposedSubclass 6.1Acute toxicity(inhalation)Subclass 6.3/8.2Skin irritancy /corrosionSubclass 6.4/8.3Eye irritancy /corrosionSubclass 6.5ARespiratorysensitisationSubclass 6.5BContactsensitisationSubclass 6.6MutagenicitySubclass 6.7Carcinogenicity6.1D No 6.1A 6.1B 6.1B 6.1C 6.1A 6.1C 6.1D No 6.1B 6.1C 6.1A 6.1B6.3B ND 6.3B No 6.3B 6.3B No 6.3B ND 6.3B8.3A 6.4A No 6.4A 6.4A No 6.4A No 6.4AND ND ND ND ND ND ND6.5B 6.5B 6.5B 6.5B 6.5B 6.5B 6.5BNo ND 6.6B ND 6.6B 6.6B ND ND 6.6B ND 6.6B6.7B 6.7B 6.7B 6.7B 6.7B 6.7B 6.7BDichlorvos reassessment – application Page 27 <strong>of</strong> 436
Hazard Class /SubclassClassificationsReady to use liquidcontaining 4.4 g/ldichlorvos & 9.6 g/lpropoxurEmulsifiableconcentratecontaining 1000 g/ldichlorvosAerosol containing50 g/kg dichlorvosEmulsifiableconcentratecontaining 1140g/l dichlorvosFlammableaerosolcontaining 3.1 g/ldichlorvos and8.7 g/l propoxurDDVP insecticidestripJ72.03Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing ProposedSubclass 6.8Reproductive /developmentaltoxicitySubclass 6.9Target organsystemictoxicitySubclass 9.1AquaticecotoxicitySubclass 9.2Soil ecotoxicitySubclass 9.3TerrestrialvertebrateecotoxicitySubclass 9.4TerrestrialinvertebrateNo 6.8A No ND ND ND No6.9B 6.9A 6.9B 6.9A 6.9B 6.9A 6.9A9.1A 9.1A 9.1A 9.1A 9.1A 9.1A 9.1ANo ND 9.2D No ND 9.2D ND ND ND9.3B 9.3A 9.3B 9.3A ND 9.3B 9.3A 9.3B 9.3A 9.3B9.4C 9.4B 9.4A 9.4B 9.4A 9.4A 9.4C 9.4B 9.4A 9.4B 9.4ADichlorvos reassessment – application Page 28 <strong>of</strong> 436
Hazard Class /SubclassClassificationsReady to use liquidcontaining 4.4 g/ldichlorvos & 9.6 g/lpropoxurEmulsifiableconcentratecontaining 1000 g/ldichlorvosAerosol containing50 g/kg dichlorvosEmulsifiableconcentratecontaining 1140g/l dichlorvosFlammableaerosolcontaining 3.1 g/ldichlorvos and8.7 g/l propoxurDDVP insecticidestripJ72.03ecotoxicityNotes:* <strong>for</strong>mulation test dataExisting Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing Proposed Existing ProposedChanges to classifications are due to:acute oral toxicity classification – use <strong>of</strong> different toxicity dataacute dermal toxicity classifications –dermal exposure to aerosol considered to be relevant.acute inhalation toxicity classification – previously interpreted best study as being vapour exposure, now assessed as aerosol exposureterrestrial vertebrate ecotoxicity classification – based on summation in accordance with current practice where previously used additivity to estimatetoxicity <strong>of</strong> mixturesterrestrial invertebrate ecotoxicity classification – use <strong>of</strong> different bee toxicity data.Dichlorvos reassessment – application Page 29 <strong>of</strong> 436
3.7 LifecycleManufacture, importation, transport and storage3.7.1 Dichlorvos is imported by sea in 200 l steel drums. It is not manufactured in NewZealand currently. Transport is <strong>under</strong> UN Number 3018, Transport Hazard Class6.1, Packaging Group I and products are marine pollutants <strong>under</strong> <strong>the</strong> IMDG Code.3.7.2 The EC <strong>for</strong>mulation is manufactured in New Zealand and is also imported packagedready <strong>for</strong> sale. It is transported in 1 and 5 litre HDPE jerry cans (480 and 144 perpallet). Transport is <strong>under</strong> UN Number 3018, Transport Hazard Class 6.1, PackagingGroup Number I and products are marine pollutants <strong>under</strong> <strong>the</strong> IMDG Code.3.7.3 Dichlorvos is also imported and packaged into BV2 surface insecticide aerosols withtamper-pro<strong>of</strong> closures. 250 kg dichlorvos is imported in drums by sea per 5 yearperiod. After packaging, <strong>the</strong> aerosols are transported on pallets <strong>of</strong> 1296 aerosols (L.Bryant pers. comm.).3.7.4 Dichlorvos is also imported and packaged into 50 g/kg gas cylinders. Insectigascylinders are ei<strong>the</strong>r 6 kg or 36 kg, ArmourCrop (DDVP) are 6 kg or 31 kg. Cylindershave an AS 2473 Type 40 outlet connection and are transported up to 12 cylindersper pallet (S. Thalavaisundaram pers. comm.).3.7.5 DDVP Insecticide Strips are manufactured overseas and imported in plastic zip lockbags containing 50 hermetically sealed sachets per bag and five DDVP InsecticideStrips per sachet. DDVP Insecticide Strips are only imported by MAFBNZ and arerestricted by <strong>the</strong>ir HSNO Approval to use by that organisation. They are not <strong>for</strong> usein residential, commercial or industrial buildings, nor as an agricultural pesticide <strong>for</strong>pest control <strong>of</strong> infestations on animals such as pet collars.Use <strong>of</strong> Dichlorvos in New ZealandUse <strong>of</strong> dichlorvos as a plant protection product3.7.6 Use <strong>of</strong> dichlorvos as a plant protection product as described on <strong>the</strong> New Zealandlabels are detailed in Table 5:Table 5.Label rates and uses <strong>for</strong> dichlorvos-containing plant protectionproducts.Product Formulation type UsesArmourCrop-Insecticide(DDVP),/Aphidgas50 g/kg aerosol Greenhouse Usage:Capsicum – <strong>for</strong> control <strong>of</strong> aphidsRates:Fogging: 1 g / m 3 , 2.5 g / m 2(applied as a fog through a dosing systemdesigned and built by BOC Ltd <strong>for</strong> eachgreenhouse).Divap 1140 g/l EC Outdoor Crop Usage:Various outdoor cropsRates:Boomspray: up to 700 ml/ha;Mistblower: up to 90 ml / 100 litre water(no water rate per hectarespecified);maximum 3 applications at 7day intervals.Handgun:apply to run<strong>of</strong>f.Indoors Crop Usage:Glasshouses & mushroom housesDichlorvos reassessment – application Page 30 <strong>of</strong> 436
Rates:Fogging: 13 ml / litre (water) / 100 m 3 ;Spraying: 26 ml / 2 litre (water) / 100 m 2 .Nuvos 1000 g/l EC Outdoor Crop Usage:Various outdoor cropsRates:Boomspray: up to 800 ml/ha;Mistblower: up to 100 ml/100 litre water(no water rate per hectarespecified);maximum 3 applications at 7day intervals.Handgun: apply to run<strong>of</strong>f.Indoors Crop Usage:Glasshouses & mushroom housesRates:Fogging: 15 ml / litre (water) / 100 m 3 ;Spraying: 30 ml / 2 litre (water) / 100 m 2 .3.7.7 The following additional in<strong>for</strong>mation relating to <strong>the</strong> use <strong>of</strong> dichlorvos on crops hasbeen acquired through discussion with users and manufacturers during <strong>the</strong>preparation <strong>of</strong> this application.3.7.8 Insectigas from BOC is ano<strong>the</strong>r 50 g/kg aerosol. It is not registered with ACVM <strong>for</strong>use in greenhouses and this use is not on <strong>the</strong> label, but an in<strong>for</strong>mation sheet 3 fromBOC does list use in greenhouses and gives a New Zealand contact address. Thisbrochure suggests application by 200 g spray into air space. Plant & Food(Appendix XXX) suggest that Insectigas cylinders may be connected to fixedpipework, or connected to hand-held spray guns or a release timer on top <strong>of</strong> <strong>the</strong>cylinder.3.7.9 Several users indicated that dichlorvos is used on an as-needed basis. HorticultureNew Zealand stated that dichlorvos is only used as needed which may be 1 year in 3<strong>for</strong> tamarillos, 1 year in 2 <strong>for</strong> glasshouses (tomatoes, capsicums, cucumbers), butmay also be used every year in glasshouses (capsicum) to break up use <strong>of</strong> Match(lufenuron) and Success (spinosad) which, used toge<strong>the</strong>r, are <strong>the</strong> only o<strong>the</strong>r productsavailable to treat Western Flower Thrips.3.7.10 Adria (pers. comm.) stated that dichlorvos is only used in 40-50% <strong>of</strong> years (crop notspecified) i.e. approximately one in every two years. NCGA (2009) indicated that43% <strong>of</strong> <strong>the</strong> Cymbidium growers use dichlorvos every year as part <strong>of</strong> pest clean-upprogrammes, 30% treat only as needed, and approximately a third <strong>of</strong> growers do notuse it.3.7.11 One correspondent stated that dichlorvos EC tends to be used once, shortly be<strong>for</strong>eharvest and only if an insect problem is identified, its volatility making it ideal <strong>under</strong><strong>the</strong>se conditions. At o<strong>the</strong>r times o<strong>the</strong>r pesticides are used (J. Hicking pers. comm.).Ano<strong>the</strong>r importer said that dichlorvos EC may be used up to 3 times at 7 dayintervals, but also said that it tends to be used shortly pre-harvest (L. Stulich pers.comm.).3.7.12 Horticulture New Zealand stated that several o<strong>the</strong>r products used in greenhouses arenot compatible with IPM and that if dichlorvos was not available glasshouse growerswould use less IPM.3 https://boc.com.au/boc_sp/downloads/gas_brochures/BOC_Pestigas_Brochure.pdfDichlorvos reassessment – application Page 31 <strong>of</strong> 436
3.7.13 Dichlorvos is currently not used by New Zealand mushroom growers, on cereals orturf, although <strong>the</strong>se are registered uses (Appendix N).3.7.14 In general, glasshouse growers use fogging equipment, only <strong>the</strong> smaller growersspray <strong>the</strong> crop. The reason is <strong>the</strong> availability <strong>of</strong> <strong>the</strong> equipment (Roelf Schreuder pers.comm.).Uses <strong>of</strong> dichlorvos o<strong>the</strong>r than as a plant protection product3.7.15 Dichlorvos <strong>for</strong>mulations are put to uses o<strong>the</strong>r than <strong>for</strong> plant protection. Labeldescriptions <strong>of</strong> <strong>the</strong>se uses are:Table 6.Label rates and uses <strong>for</strong> dichlorvos-containing products <strong>for</strong> non-plantprotection uses.Product Formulation type UsesDivap 1140 g/l EC Farm buildings:Farm buildings, empty stables, piggeriesand poultry housesRates (maximum):Fogging: 13 ml / litre / 100 m 3Spraying: 26 ml / 2 litre / 100 m 2 .Public health outdoors:Parks, beaches, sports areasRates:Fogging: 4 ml / litre.Fly breeding areasRates:Spraying: 13 ml/5 litre/10 m 2 .Public health Indoors:Hospitals, restaurants, canteens, cinemas,public halls, industrial plants, warehouses,food plantsRates:Fogging: 4, 9 or 13 ml / litre / 100 m 3depending on pestSpraying: 8, 18, or 26 ml / 2 litre / 100 m 2 .Nuvos 1000 g/l EC Farm buildings:Farm buildings, empty stables, piggeriesand poultry housesRates (maximum):Fogging: 15 ml / litre / 100 m 3Spraying: 30 ml / 2 litre / 100 m 2 .Public health outdoors:Parks, beaches, sports areasRates:Fogging: 5 ml / litre.Fly breeding areasRates:Spraying: 15 ml/5 litre/10 m 2 .Public health Indoors:Hospitals, restaurants, canteens, cinemas,Dichlorvos reassessment – application Page 32 <strong>of</strong> 436
BV2 SurfaceInsecticideBV2 SurfaceInsecticide Bulk3.1 g/l aerosol (dualactive with propoxur at8.7 g/l)4.4 g/l dichlorvosready-to-use liquid,(dual active with 9.6g/l propoxur).public halls, industrial plants, warehouses,food plantsRates:Fogging: 5, 10 or 15 ml / litre / 100 m 3depending on pestSpraying: 10, 20, or 30 ml / 2 litre / 100 m 2 .Surface treatmentskirting boards, library shelves, architravesetc.Rate:Spray affected areas until damp.Surface treatmentskirting boards, library shelves, architravesetc.Rate:Spray affected areas until damp.Insectigas 50 g/kg aerosol Spray treatmentRate:Spraying:100 g / 100 m 3 (18 s spray into air);300 g / 100 m 3 (54 s spray into cracks &crevices);200 g / 300 m 3 (70 s spray into air orcrevice).DDVP InsecticideStripJ72.03 ismanufactured <strong>for</strong>export180 g/kg vapourreleasing strip5-24% dichlorvos, gascylindersUsed in fruit fly traps <strong>for</strong> fruit flymonitoring by MAF-BNZ.Export only3.7.16 The following additional in<strong>for</strong>mation has been acquired through discussions withusers and manufacturers during <strong>the</strong> preparation <strong>of</strong> this application.3.7.17 Nuvos and Divap have treatment <strong>of</strong> grain moths, flour beetles, grain weevils andflour mites pests on <strong>the</strong> label, but listed against industrial plants, warehouses andfood plants. It is <strong>the</strong>re<strong>for</strong>e unclear whe<strong>the</strong>r <strong>the</strong> NZ label supports treatment <strong>of</strong> grainor just <strong>the</strong> buildings used to store grain. Grain is treated overseas but it is not knownif this is done in NZ (Appendix K).3.7.18 About 25,000 cans <strong>of</strong> BV2 Surface Insecticide each containing 600 ml product areused per year. A maximum <strong>of</strong> two applications are made 2 weeks apart and 6 weeks<strong>of</strong> protection should result. (L. Bryant pers. comm.).3.7.19 Four or five glass jars <strong>of</strong> BV2 surface insecticide bulk each containing 4 litre productare used per year (L. Bryant pers. comm.).3.7.20 The application <strong>for</strong> dichlorvos strips to use in <strong>the</strong> fruit fly surveillance programme,said that up to 50,000 strips would be imported per year. In <strong>the</strong> current programmefewer strips are actually used. They are used all over NZ but in different densities.Single strips are contained within traps that also contain fruit fly lures. The strips arereplaced at 6-8 week intervals.Dichlorvos reassessment – application Page 33 <strong>of</strong> 436
3.8 Use Scenarios3.8.1 To evaluate <strong>the</strong> exposure risks to human health or <strong>the</strong> environment from use <strong>of</strong>dichlorvos in agricultural and non-agricultural situations. a suite <strong>of</strong> Use Scenarioswere developed.3.8.2 Agricultural Use Scenarios are based on label rates, in<strong>for</strong>mation from <strong>the</strong> Plant &Food use survey (Appendix N) and <strong>the</strong> above personnel communication (Table 7).Dichlorvos reassessment – application Page 34 <strong>of</strong> 436
Table 7.Dichlorvos outdoor and indoor plant protection Use Scenarios.UseScenarioOutdoorCrop/Use Method Rate <strong>Application</strong>s Basis <strong>for</strong> scenarioEquipment Details Formulationtype<strong>Application</strong>rateArea orvolumetreatedNo.peryearInterval(days)<strong>Application</strong> rateArea or volumetreated1 Strawberries Low boom Fine – EC 800 20 ha 1 - Nuvos label. O<strong>the</strong>r crops may use slightlymediumg a.i./halower rates e.g. cereals 750 g a.i./ha2 droplet2 7BBA model3 Vegetables, High boom Fine – EC 800 20 ha 1 -cereals,mediumg a.i./ha4 berriesdroplet2 75 Fruitairblast Finemediumg a.i./ha(Appendix K gives 2000 l/ha <strong>for</strong> persimmon,EC 2052 8 ha 1 - Divap label gives 90 ml/100 L. Plant & Food(tamarillo/6 persimmons/droplet2 7 giving 2052 g a.i/ha <strong>for</strong> Divap. O<strong>the</strong>r crops mayberry)use lower water rates e.g. max <strong>of</strong> 900 l/ha <strong>for</strong>tamarillo (Horticulture New Zealand pers.comm.).BBA model7 Passionfruit knapsack Finemediumg a.i./haEC 1026 1 ha 1 - Divap label BBA model8 droplet2 7Indoorfog RTU gas 0.05 31250 m 39 Glasshouse Automatic1 - Armourcrop and Nuvos labels.crops/ application a g/m 3 (1.25 ha, 2.5<strong>Application</strong> frequency may be more frequent10mushroomsm high2 7than in Scenario 10 (3-5 times/yr <strong>for</strong> capsicum,11 EC glasshouse) 1 - Horticulture New Zealand pers. comm.). butgiven <strong>the</strong> rapid dissipation, frequency <strong>of</strong>12 2 7exposure has no effect on <strong>the</strong> risk (Appendix G).Nuvos label says may be applied as a lightspray, but Plant & Food (2009) indicate it isonly fogged. See too, Scenarios 15 & 16.R. Schreuder(pers. comm.)Dichlorvos reassessment – application Page 35 <strong>of</strong> 436
UseScenarioCrop/Use Method Rate <strong>Application</strong>s Basis <strong>for</strong> scenarioEquipment Details Formulationtype<strong>Application</strong>rateArea orvolumetreatedNo.peryearInterval(days)<strong>Application</strong> rateArea or volumetreated13 Glasshouse Automatic fog/low EC 0.05 g/m 3 0.1 ha 1 - NCGO pers. comm.. NCGO pers.flowers application volumecomm..14 (cymbidium)mister2 715 Hand held Finemediumg a.i./haEC 1800 0.2 ha 1 -sprayer16 droplet2 7a Automatic application equipment assumes remote application (i.e. applicators not in <strong>the</strong> space being treated), so that occupational exposure is confined to mixer/loader, or in <strong>the</strong> case <strong>of</strong>gas products, connecting/disconnecting cylinders;3.8.3 Non-agricultural usage <strong>of</strong> dichlorvos has been assessed based on <strong>the</strong> Use Scenarios identified in Table 8. These Use Scenarios were developedbased on label in<strong>for</strong>mation, communication from users, registrants and manufacturers.Table 8.Dichlorvos non-agricultural Use Scenarios.Scenario Crop/Use Method Rate <strong>Application</strong>s Basis <strong>for</strong> scenarioEquipment Details Formulation<strong>Application</strong>rateArea orvolumetreatedNo.peryearInterval(days)<strong>Application</strong> rateArea or volumetreatedIndoor17 Enclosed Automatic fog RT U 0.05 & 0.15 375, 3750 1 - Armourcrop label APVMA (XXX)space applicationgas g a.i./ m 3 & 1250018 (industrial)m 3 ) 2 719 ManualfoggerfogRT Ugas1 -2 7Dichlorvos reassessment – application Page 36 <strong>of</strong> 436
Scenario Crop/Use Method Rate <strong>Application</strong>s Basis <strong>for</strong> scenarioEquipment Details Formulation<strong>Application</strong>rateArea orvolumetreatedNo.peryearInterval(days)<strong>Application</strong> rateArea or volumetreated20 Automatic fog EC 1 -application21 2 722 Manual fog EC 1 -fogger23 2 724 High Fine- EC 0.1 & 0.31 - Nuvos label ???pressure mediumg a.i./ m 225 hand-wand droplet2 7orequivalent26 Domestic use RTU3.1 1 x 600 ml1 - Internal assessment <strong>of</strong> worst case use Internalaerosolg ai/L canassessment <strong>of</strong>27 2 7worst case use28 knapsack Finemediumliquidassessment <strong>of</strong>RTU 4 L 60 m 2 1 - Internal assessment <strong>of</strong> worst case use Internal29 droplet2 7worst case useOutdoor – public space30 Publicoutdoor useManualfoggerOutdoor – Biosecurity use <strong>of</strong> DDVP Insecticide StripFog EC 1000 ga.i./ha1 ha 1 - Nuvos label Internalassessment <strong>of</strong>worst case use31 See description belowO<strong>the</strong>r – manufacture <strong>for</strong> export32 No use details required <strong>for</strong> this Use ScenarioDichlorvos reassessment – application Page 37 <strong>of</strong> 436
3.8.4 In <strong>the</strong> application <strong>for</strong> <strong>the</strong> DDVP Insecticide Strip (Use Scenario 31 - HSR04011), itwas stated:“MAF have a specification <strong>for</strong> <strong>the</strong> surveillance <strong>for</strong> fruit flies including <strong>the</strong> fieldoperation <strong>of</strong> traps. The contractor must comply with this specification. Appendix A,Section 6. Fruit fly traps are usually set up from late August in nor<strong>the</strong>rn NewZealand and later in <strong>the</strong> year fur<strong>the</strong>r south as <strong>the</strong> temperatures increase. The trapsremain in place until June <strong>of</strong> <strong>the</strong> following year. The trap is a plastic containertypically 85 mm in diameter at base, 105 mm diameter at top and 100 mm deep. Theremovable lid is 110 mm in diameter. The base <strong>of</strong> <strong>the</strong> trap has four small drainageholes (2.5mm diameter) directly below <strong>the</strong> fruit fly entry holes. The four fruit flyentry holes are located 15 mm below <strong>the</strong> lip <strong>of</strong> <strong>the</strong> trap; <strong>the</strong>se holes are 25 mm indiameter. Appendix A, Section 6 The lure traps contain one <strong>of</strong> three syn<strong>the</strong>tic maleattractants. The choice <strong>of</strong> lure is specific to a species <strong>of</strong> fruit fly. The DDVPINSECTICIDE STRIP is positioned below <strong>the</strong> lure in <strong>the</strong> bottom <strong>of</strong> <strong>the</strong> trap. Thetraps are recommended to be placed ei<strong>the</strong>r 400 or 1200 metres apart (one to 6.25traps per km 2 ) depending on <strong>the</strong> type <strong>of</strong> lure. The traps are placed in potential hostplants, ideally well foliaged and trees bearing fruit. Most importantly traps are nothung below foliage and no closer than 1.3 metres to <strong>the</strong> ground. If <strong>the</strong>re is more thanone trap on a property <strong>the</strong>n <strong>the</strong>se are not placed in <strong>the</strong> same tree and must be at least3 metres apart. The property owner / occupier receives a letter and is briefed on <strong>the</strong>material used in <strong>the</strong> traps and is requested to report any interference or damage to<strong>the</strong> trap to a freephone number operated by <strong>the</strong> contractor. Appendix 9. Each trap isinspected two weekly and <strong>the</strong> DDVP INSECTICIDE STRIP is replaced 6-weekly.Replacement <strong>of</strong> <strong>the</strong> lure is 6 or 12-weekly depending on <strong>the</strong> type <strong>of</strong> lure. Proceduresare followed to ensure lures are not mixed and that <strong>the</strong>re is no contamination <strong>of</strong>traps nor <strong>of</strong> <strong>the</strong> area around <strong>the</strong> trap. In <strong>the</strong> event <strong>of</strong> a trap being blown from <strong>the</strong>host tree <strong>the</strong>n <strong>the</strong> DDVP INSECTICIDE STRIP must be recovered and disposed <strong>of</strong>safely. The contractor is required to wear gloves and to use tweezers when handling<strong>the</strong> lures or DDVP INSECTICIDE STRIP. Traps are replaced if damaged orautomatically at <strong>the</strong> end <strong>of</strong> each season.”“ The trap operators setting up <strong>the</strong> fruit fly trapping stations are not expected tohave > 10 kg DDVP INSECTICIDE STRIPS (equivalent to 800 sachets) <strong>under</strong> <strong>the</strong>ircontrol at any time. The largest trap run in Auckland comprises 45 traps, <strong>the</strong>re<strong>for</strong>e<strong>the</strong> season’s total requirement <strong>for</strong> this single run is 315 strips. Auckland runs areserviced from <strong>the</strong> Agriquality laboratory at Lynfield, and while an operator mayservice up to one and a half runs on a day (wea<strong>the</strong>r constraints) <strong>the</strong> maximumnumber <strong>of</strong> strips and operator would have in a vehicle at one time is about 90 (
humidity conditions. The higher residual concentration in <strong>the</strong> strip being replacedmeans that greater care is needed in handling <strong>the</strong> strip during replacement in <strong>the</strong>trap and with <strong>the</strong> disposal <strong>of</strong> <strong>the</strong> used strips.Potential exposure <strong>of</strong> contractors carrying opened sachets might arise in a vehicle(confined space). However contractors are trained to roll over <strong>the</strong> torn opening toreseal <strong>the</strong> sachet. This not only protects from potential exposure by inhalation butalso helps ensure unused strips do not become prematurely depleted <strong>of</strong> <strong>the</strong> activecomponent.“3.8.5 On <strong>the</strong> basis <strong>of</strong> this in<strong>for</strong>mation a Use Scenario <strong>for</strong> operator exposure was developedas follows. The operator will service 90 traps in a day, spending 2 minutes at eachtrap, giving an exposure <strong>of</strong> 3 hours per day. 41% <strong>of</strong> <strong>the</strong> 520 mg dichlorvos on a stripwill be emitted continuously over <strong>the</strong> 6 week (1008 hours) service life <strong>of</strong> a strip in atrap, giving an emission rate <strong>of</strong> 0.21 mg dichlorvos / hour. There will be no build-up<strong>of</strong> dichlorvos within a trap and an operator will inhale all <strong>the</strong> dichlorvos beingemitted from a trap as <strong>the</strong>y bend over it to service it, but will not be exposed to anydichlorvos while travelling between traps, i.e. operators will be exposed to 0.21 mgdichlorvos / hour <strong>for</strong> 3 hours per day. The risks posed to operators based on <strong>the</strong>sefigures are detailed in paragraph 4.4.4.1.3.9 Existing Controls3.9.1 The lifecycle and hazardous properties <strong>of</strong> dichlorvos and its <strong>for</strong>mulations aremanaged through a variety <strong>of</strong> controls. These controls are prescribed as part <strong>of</strong> <strong>the</strong>approval <strong>of</strong> <strong>the</strong>se substances <strong>under</strong> <strong>the</strong> Act and <strong>the</strong> Agricultural Compounds andVeterinary Medicines Act 1997 (ACVM Act), and through requirements <strong>for</strong> resourceconsents <strong>under</strong> <strong>the</strong> Resource Management Act 1991.3.9.2 The HSNO Act controls applicable to dichlorvos and its <strong>for</strong>mulations are given inAppendix J. A summary <strong>of</strong> conditions <strong>under</strong> <strong>the</strong> ACVM Act is also given inAppendix J.3.9.3 In Section 4, <strong>the</strong> risks, costs and benefits <strong>of</strong> dichlorvos are identified and assessed.This assessment is made <strong>under</strong> <strong>the</strong> assumption that <strong>the</strong>re is compliance with <strong>the</strong>existing controls.Dichlorvos reassessment – application Page 39 <strong>of</strong> 436
SECTION 4 – IDENTIFICATION AND ASSESSMENT OFADVERSE AND BENEFICIAL EFFECTS (RISKS, COSTS ANDBENEFITS)4.1 Introduction4.1.1 The potential sources <strong>of</strong> risk to human health and to <strong>the</strong> environment are tabulated inTable 9.Table 9.Identification <strong>of</strong> potential sources <strong>of</strong> risk.Lifecycle ActivityFormulation &packagingLocal transportStorageUseDisposalAssociated Source <strong>of</strong> RiskAn incident during <strong>for</strong>mulation or packagingTransport or handling incident on roads or during loading/unloadingresulting in spillage and subsequent exposure <strong>of</strong> people and/or <strong>the</strong>environmentIncident during storage, resulting in spillage and subsequent exposure <strong>of</strong>people and/or <strong>the</strong> environmentExposure to users, bystanders and/or <strong>the</strong> environment during dilution,mixing or changing <strong>of</strong> cylinders or use, or through exposure to residues ontreated vegetation, soil, feed items.Disposal <strong>of</strong> <strong>the</strong> substance or containers, resulting in release <strong>of</strong> <strong>the</strong>substance and subsequent exposure <strong>of</strong> people and/or <strong>the</strong> environment4.2 IncidentsNew Zealand Incidents4.2.1 ERMA New Zealand notes <strong>the</strong> absence <strong>of</strong> relevant incident in<strong>for</strong>mation relating to<strong>the</strong> use <strong>of</strong> dichlorvos in New Zealand. This could be due ei<strong>the</strong>r to a lack <strong>of</strong> incidentsor a lack <strong>of</strong> reporting/ monitoring.Overseas Reports4.2.2 USEPA (2006) discusses human incident data collected from <strong>the</strong> AmericanAssociation <strong>of</strong> Poison Control Centres. Although a large number (21006) <strong>of</strong>exposures were reported, most involved homeowner products containing dichlorvosin association with o<strong>the</strong>r pesticides. The few reports involving dichlorvos alone,‗usually do not involve any significant acute symptoms that would require medicaltreatment‘. USEPA (2006) also discusses epidemiological studies examiningincreased incidence <strong>of</strong> childhood cancer and prostate cancer from exposure todichlorvos and concludes that confounding factors in <strong>the</strong> study design could explainany effects seen.4.2.3 USEPA (2006) also discusses environmental incident data reported from 1991 to2002 and concludes that <strong>the</strong> incident reporting system is inadequate to pick upwhe<strong>the</strong>r effects are occurring or not.4.2.4 APVMA do not include reporting <strong>of</strong> incidents in <strong>the</strong>ir draft review <strong>of</strong> dichlorvos(APVMA, 2008).Dichlorvos reassessment – application Page 40 <strong>of</strong> 436
4.3 EnvironmentIdentification <strong>of</strong> adverse effects (risks and costs)4.3.1 At all steps in <strong>the</strong> lifecycle (Table 9) <strong>the</strong>re is potential <strong>for</strong> dichlorvos to enter <strong>the</strong>environment.4.3.2 Dichlorvos is very toxic to aquatic life, terrestrial vertebrates and terrestrialinvertebrates and harmful to soil organisms. Exposure <strong>of</strong> <strong>the</strong> environment could<strong>the</strong>re<strong>for</strong>e result in significant effects.Assessment <strong>of</strong> potentially significant adverse effects (risks and costs)4.3.3 ERMA New Zealand assesses <strong>the</strong> significance <strong>of</strong> adverse effects by comparing <strong>the</strong>environmental exposure with existing controls in place to <strong>the</strong> concentration causingeffects.4.3.4 Given <strong>the</strong> default controls, any incidents would be likely to be localised and could be<strong>of</strong> no more than moderate magnitude if waterways became contaminated bysignificant quantities <strong>of</strong> dichlorvos. The likelihood <strong>of</strong> such effects resulting fromincidents/spills during repackaging, local transport, storage or disposal <strong>of</strong> dichlorvosproducts is considered to be highly improbable. This combination <strong>of</strong> likelihood andmagnitude indicates suggests a negligible risk 4 .4.3.5 The environmental effects that may arise from outdoor public health use (UseScenario 30) would be localised in extent and duration and <strong>the</strong>re<strong>for</strong>e would beconsidered moderate in magnitude. ERMA New Zealand considers <strong>the</strong> likelihood <strong>of</strong>moderate effects to be unlikely, given <strong>the</strong> comparatively small areas that would betreated and <strong>the</strong> rapid dissipation <strong>of</strong> dichlorvos. This combination <strong>of</strong> likelihood andmagnitude also suggests a low risk.4.3.6 ERMA New Zealand considers that t<strong>the</strong> magnitude <strong>of</strong> effects to <strong>the</strong> environment thatmay arise from dichlorvos use in biosecurity fruit fly monitoring traps (Use Scenario31) are minimal. The likelihood <strong>of</strong> environmental effects resulting from isconsidered highly improbable given <strong>the</strong> enclosed nature <strong>of</strong> <strong>the</strong> traps and <strong>the</strong>specificity <strong>of</strong> <strong>the</strong> lures that attract pests to <strong>the</strong>m. This combination <strong>of</strong> likelihood andmagnitude suggests a negligible risk.4.3.7 ERMA New Zealand modelled likely exposure during <strong>the</strong> use <strong>of</strong> dichlorvosaccording to <strong>the</strong> scenarios in Table 7. In determining exposure, ERMA NewZealand made no allowance <strong>for</strong> buffer zones around fields. L. Stulich (pers. comm.)indicated that 5 - 10 m hedging buffer zones are used, Horticulture New Zealandsuggested 4-6 m shelter belts are used <strong>for</strong> tamarillos, but ERMA New Zealand doesnot know if this is standard practice.4.3.8 Details <strong>of</strong> <strong>the</strong> environmental exposure modelling are presented in Appendix C.4The ERMA New Zealand qualitative risk matrix based on evaluation <strong>of</strong> likelihood and magnitude <strong>of</strong> risk isgiven in Appendix JDichlorvos reassessment – application Page 41 <strong>of</strong> 436
4.3.9 The conclusions <strong>of</strong> this risk assessment are:4.3.9.1 Aquatic environment – surface water:Fish:- <strong>the</strong> level <strong>of</strong> risk to fish from any <strong>of</strong> <strong>the</strong> outdoor Use Scenarios(1 to 8) is not significant, as indicated by risk quotients
4.3.9.3 Aquatic environment - Groundwater:Tier 0 modelling <strong>of</strong> concentrations in groundwater predictsconcentrations from 0.00069 to 0.0036 µg/L.Such concentrations are unlikely to be significant.4.3.9.4 Aquatic environment - Marine:No marine assessment was made;Given <strong>the</strong> fate <strong>of</strong> dichlorvos, adverse effects to <strong>the</strong> marineenvironment are considered unlikely.4.3.9.5 Terrestrial environment – birds:All plant protection Use Scenarios (1 - 8) give rise to exposure <strong>of</strong>birds through consumption <strong>of</strong> crops or invertebrates to whichdichlorvos was applied, and indicates a significant, non-negligiblerisk;There is significant uncertainty about this conclusion since <strong>the</strong>acute oral toxicity data, that are used in <strong>the</strong> analysis, indicate LD 50values (expressed in mg/kg bw/d) more than 100 times lower than<strong>the</strong> LC 50 values defined in <strong>the</strong> dietary toxicity studies (expressed inppm or mg/kg feed). A factor <strong>of</strong> 10x is normally expected (EFSA,2008), and likely reflects rapid dissipation <strong>of</strong> dichlorvos from food;LD 50 values are used in risk assessment due to difficulties indetermining how much food is eaten in dietary studies. However,given that <strong>the</strong> dietary route <strong>of</strong> exposure is <strong>the</strong> route by which birdsare exposed in <strong>the</strong> field and, given <strong>the</strong> rapid dissipation <strong>of</strong>dichlorvos, <strong>the</strong> dietary data should also be considered. If this isdone, <strong>the</strong> risk quotients may be presumed to be overestimated quiteprobably by a factor <strong>of</strong> 10 which will reduce <strong>the</strong> risk to around <strong>the</strong>level <strong>of</strong> concern.4.3.9.6 Terrestrial – soil-dwelling invertebrates:Plant protection Use Scenarios (1 to 4, 7 to 8) give rise toinsignificant exposure <strong>of</strong> soil-dwelling invertebrates: <strong>the</strong> risks areassessed as being low outside <strong>the</strong> application area and also within<strong>the</strong> application area;Use Scenarios 5 and 6 (airblast application) gives rise to significant,non-negligible risk <strong>of</strong> exposure. The details <strong>of</strong> <strong>the</strong> earthwormtoxicity study on which this conclusion is reached are not available,but it is likely that dichlorvos was dosed to <strong>the</strong> test system withoutrenewal, <strong>the</strong>re<strong>for</strong>e <strong>the</strong> exposure in <strong>the</strong> test and <strong>under</strong> fieldconditions would be similar;Consequently, <strong>the</strong>se conclusions are reached with low uncertainty.Dichlorvos reassessment – application Page 43 <strong>of</strong> 436
4.3.9.7 Terrestrial – non-target invertebrates:The risks to bees are concluded to be very high from Use Scenarios1 to 8;This conclusion is based on a Tier 0 model in which applicationrate is related to bee toxicity. This model has been ‗validated‘against field observations <strong>of</strong> effects;Results <strong>of</strong> o<strong>the</strong>r trials are equivocal. APVMA (2008) mention <strong>the</strong>results <strong>of</strong> a foliar residue study in which <strong>the</strong> LD 50 was reported tobe 0.2 kg ai/ha, which is less than New Zealand application rates,but no o<strong>the</strong>r in<strong>for</strong>mation was available. By contrast, US EPA(2006) report <strong>the</strong> results <strong>of</strong> a study on <strong>the</strong> toxicity <strong>of</strong> foliar residuesto honey bees and showed residues <strong>of</strong> dichlorvos applied at 0.5 lbai/A (= 0.56 kg ai/ha) were practically nontoxic to honey bees threehours post treatment;Limited data on effects on o<strong>the</strong>r non-target invertebrates indicaterisks at field application rates.4.3.9.8 Terrestrial – plants:No data were identified to evaluate <strong>the</strong> effects <strong>of</strong> dichlorvos on plantsei<strong>the</strong>r through foliar or soil exposure.4.3.9.9 Bioconcentration:On <strong>the</strong> basis <strong>of</strong> low log K ow , dichlorvos will not bioconcentrate.4.3.10 Very little environmental exposure is expected from dichlorvos usage in indoorlocations, such as greenhouses (Use Scenarios 9 to 16), given that <strong>the</strong> substance isnot applied in a wide-dispersive manner that could expose <strong>the</strong> aquatic or terrestrialenvironments, and that dichlorvos is rapidly dissipated. This risk has not beenconsidered fur<strong>the</strong>r.4.3.11 ERMA New Zealand expects that domestic use and non-agricultural enclosed spaceusage (Use Scenarios 17 to 29) will not give rise to any significant risk to <strong>the</strong> aquaticor terrestrial environments. This risk has not been considered fur<strong>the</strong>r.Identification <strong>of</strong> beneficial effects (benefits)4.3.12 ERMA New Zealand did not identify any beneficial effects on <strong>the</strong> environment from<strong>the</strong> use <strong>of</strong> dichlorvos.4.4 Human health and safetyIdentification <strong>of</strong> adverse effects (risks and costs)4.4.1 Each <strong>of</strong> <strong>the</strong> lifecycle activities listed in Table 9 has <strong>the</strong> potential to expose people todichlorvos.Assessment <strong>of</strong> potentially significant adverse effects (risks and costs)4.4.2 Given <strong>the</strong> default controls, any incidents would be likely to be localised but could be<strong>of</strong> minimal to major magnitude. The likelihood <strong>of</strong> effects resulting fromincidents/spills during manufacture, repackaging, local transport, storage or disposalDichlorvos reassessment – application Page 44 <strong>of</strong> 436
is considered to be highly improbable. This combination <strong>of</strong> likelihood andmagnitude suggests a negligible to low risk. 54.4.3 ERMA New Zealand modelled likely exposure <strong>of</strong> people during use <strong>of</strong> dichlorvos<strong>for</strong> <strong>the</strong> Use Scenarios <strong>for</strong> which appropriate modelling techniques exist. Details <strong>of</strong><strong>the</strong> human exposure modelling are presented in Appendix G. These quantitativeestimates <strong>of</strong> exposure are related to concentrations calculated to cause effects toderive risk quotients. Given <strong>the</strong> complexity <strong>of</strong> <strong>the</strong> overall use pattern <strong>of</strong> dichlorvoscontainingsubstances, ERMA New Zealand has extracted <strong>the</strong> risk quotient data andprovided a summary plot as part <strong>of</strong> Appendix G to accompany <strong>the</strong> complete humanhealth exposure report.4.4.4 The conclusions <strong>of</strong> this risk assessment are:4.4.4.1 Operators:Although exposure to dichlorvos has potential to cause majorhealth effects, ERMA New Zealand considers that, given <strong>the</strong>requirements <strong>for</strong> packaging, transportation, storage, and <strong>the</strong> skilllevels <strong>of</strong> those persons involved in <strong>the</strong>se stages <strong>of</strong> <strong>the</strong> lifecycles <strong>of</strong>dichlorvos-containing products, ERMA New Zealand considers thatit is sufficiently unlikely that such adverse effects could occur.Additionally, ERMA New Zealand considers that it is highlyimprobable that even moderate adverse effects could occur.ERMA New Zealand has summarised and reviewed <strong>the</strong> riskquotients (RQs) calculated <strong>for</strong> <strong>the</strong> various Use Scenarios. Due to<strong>the</strong> variety <strong>of</strong> Use Scenarios <strong>for</strong> dichlorvos-containing<strong>for</strong>mulations, <strong>the</strong> Use Scenarios have been grouped, based on <strong>the</strong>calculated RQ values. Certain Use Scenarios have been evaluatedwith a variety <strong>of</strong> operating conditions (e.g. using multiple 7Lcylinders vs. a single 35L cylinder), and due to those conditionsmay feature in several Risk Groups. In this event, only <strong>the</strong> lowestrisk group (and its associated conditions) <strong>for</strong> a particular UseScenario is identified. Also detailed in Table 10 are <strong>the</strong> conditionsupon which <strong>the</strong> Risk Quotient in question was determined.Where exposures have been determined to be negligible only whencertain conditions are adhered to, ERMA New Zealand considersthat those risks are non-negligible unless those conditions arespecified and implemented.5The ERMA New Zealand qualitative risk matrix based on evaluation <strong>of</strong> likelihood and magnitude <strong>of</strong> risk isgiven in Appendix J.Dichlorvos reassessment – application Page 45 <strong>of</strong> 436
Table 10.Summary <strong>of</strong> occupational risk quotients <strong>for</strong> <strong>the</strong> Use Scenarios <strong>of</strong> dichlorvos usage.RiskGroupRQ range Level <strong>of</strong> risk UseScenariosConditionsComments1 0 < RQ ≤ 1 Negligible 9 No cylinder changes, using35L cylinders.Automated application. Exposure occurs at connection anddisconnection <strong>of</strong> cylinders.Specific PPE requirements.10 No cylinder changes.Specific PPE requirements.Automated application. Exposure occurs at connection anddisconnection <strong>of</strong> cylinders.13 Specific PPE requirements. Automated application. Exposure occurs during mixingand loading.14 Specific PPE requirements. Automated application. Exposure occurs during mixingand loading.17 Up to 1 cylinder change peroperator per day.Automated application. Exposure occurs at connection anddisconnection <strong>of</strong> cylinders.Specific PPE requirements.18 Up to 1 cylinder change peroperator per day.Automated application. Exposure occurs at connection anddisconnection <strong>of</strong> cylinders.Specific PPE requirements.19 Specific PPE requirements.Maximum treated arearestriction.Manual application. Exposure occurs during mixing,loading and application.Dichlorvos reassessment – application Page 46 <strong>of</strong> 436
RiskGroupRQ range Level <strong>of</strong> risk UseScenariosConditionsComments20 Specific PPE requirements.Maximum quantity <strong>for</strong>mixing restriction.21 Specific PPE requirements.Maximum quantity <strong>for</strong>mixing restriction.22 Specific PPE requirements.Maximum quantity <strong>for</strong>mixing and applicationrestriction.23 Specific PPE requirements.Maximum quantity <strong>for</strong>mixing and applicationrestriction.24 Specific PPE requirements.Maximum quantity <strong>for</strong>mixing, application andtreated area restriction.25 Specific PPE requirements.Maximum quantity <strong>for</strong>mixing, application andAutomated application. Exposure occurs during mixingand loading.Automated application. Exposure occurs during mixingand loading.Manual application. Exposure occurs during mixing,loading and application.Manual application. Exposure occurs during mixing,loading and application.Manual application. Exposure occurs during mixing,loading and application.Manual application. Exposure occurs during mixing,loading and application.Dichlorvos reassessment – application Page 47 <strong>of</strong> 436
RiskGroupRQ range Level <strong>of</strong> risk UseScenariosConditionsCommentstreated area restriction.2 1 < RQ ≤ 10 Non-negligible 1 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.It may be possible to reduce <strong>the</strong> level <strong>of</strong> risk tolevels through use <strong>of</strong> additional controls (i.e.more restricted use parameters in comparisonto those used to determine <strong>the</strong> RQ values), suchthat <strong>the</strong> level <strong>of</strong> benefit outweighs <strong>the</strong> level <strong>of</strong>risk.2 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.3 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.4 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.11 Specific PPE requirements. Automated application. Exposure occurs during mixingand loading.12 Specific PPE requirements. Automated application. Exposure occurs during mixingand loading.15 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.16 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.26 No PPE specified. Domestic use product – assumed that no PPE would beused. Exposure occurs during application.27 No PPE specified. Domestic use product – assumed that no PPE would beused. Exposure occurs during application.Dichlorvos reassessment – application Page 48 <strong>of</strong> 436
RiskGroupRQ range Level <strong>of</strong> risk UseScenariosConditionsComments30 Specific PPE requirements. Manual application. Exposure occurs during mixing,loading and application.3 10 < RQ < ∞ Non-negligible(high)It is not likely to be possible to reduce <strong>the</strong> level<strong>of</strong> risk to acceptable levels through use <strong>of</strong>additional controls.5 Max. PPE used inmodelling.6 Max. PPE used inmodelling.7 Max. PPE used inmodelling.8 Max. PPE used inmodelling.Manual application. Exposure occurs during mixing,loading and application.Manual application. Exposure occurs during mixing,loading and application.Manual application. Exposure occurs during mixing,loading and application.Manual application. Exposure occurs during mixing,loading and application.28 No PPE specified. Domestic use product – assumed that no PPE would beused. Exposure occurs during application.29 No PPE specified. Domestic use product – assumed that no PPE would beused. Exposure occurs during application.Dichlorvos reassessment – application Page 49 <strong>of</strong> 436
ERMA New Zealand was not able to quantitatively assess <strong>the</strong> risk<strong>of</strong> exposure to operators arising from <strong>the</strong> use <strong>of</strong> dichlorvosimpregnatedinsecticide strips (Use Scenario 31). Given <strong>the</strong> usepattern described <strong>for</strong> DDVP Insecticide strips, <strong>the</strong> criteria used todevelop <strong>the</strong> Use Scenario, ERMA New Zealand has <strong>under</strong>takensemi-quantitative assessment. ERMA New Zealand estimates thatoperators will be exposed to 0.21 mg / hour <strong>of</strong> operations involvingDDVP strips associated with traps (which includes placing andreplacing strips in traps, and also routine inspection <strong>of</strong> traps).ERMA New Zealand estimates that operators will be exposed <strong>for</strong> aduration <strong>of</strong> 3 hours per day (0.63 mg dichlorvos per day). It hasbeen assumed that exposure will only occur via inhalation, as PPE(i.e. gloves) will be used when handling DDVP strips. Comparing<strong>the</strong> quantity <strong>of</strong> exposure to <strong>the</strong> AOEL (0.0014 mg/kg bw / day), <strong>for</strong>a 75 kg operator <strong>the</strong> daily AOEL equates to 0.105 mg dichlorvos.ERMA New Zealand considers that, whilst <strong>the</strong> estimations arelikely to be conservative in nature, <strong>the</strong> magnitude <strong>of</strong> adverse effectposed to operators is minor to major. ERMA New Zealandconsiders that <strong>the</strong> likelihood <strong>of</strong> minor to major adverse effectsoccurring is very unlikely. The level <strong>of</strong> risk to <strong>the</strong> health <strong>of</strong>operators is <strong>the</strong>re<strong>for</strong>e negligible to low.4.4.4.2 Restricted entry exposure to operators:Only a few scenarios <strong>for</strong> existing uses <strong>of</strong> dichlorvos gaveacceptable risks <strong>for</strong> restricted entry workers. Acceptable restrictedentry generally requires <strong>the</strong> use <strong>of</strong> PPE and/or RPE plus in mostcases a time period called <strong>the</strong> Restricted Entry Interval (REI) 6 isalso needed. The level <strong>of</strong> risk <strong>of</strong> exposure associated with each UseScenario is detailed in Table 11, arising from restricted entry intotreated areas.ERMA New Zealand considers that <strong>the</strong> unrestricted entry timeperiods proposed <strong>for</strong> industrial buildings treated with dichlorvos,indicate that inhalation exposure to dichlorvos is acceptable withoutuse <strong>of</strong> RPE after such a time. ERMA New Zealand considers that<strong>the</strong> such time periods, with respect to inhalation exposure risk, canalso be imposed on glasshouse and mushroom house use.However,, given that ERMA New Zealand is not able to establish atime period after which dermal exposure has reduced to acceptablelevels, ERMA New Zealand considers that contact with treatedglasshouse and mushroom house crops after treatment require use<strong>of</strong> PPE to prevent dermal exposure.ERMA New Zealand considers that <strong>the</strong> semi-quantitativeassessments carried out <strong>for</strong> operator exposure <strong>for</strong> Use Scenario 31is appropriate to use <strong>for</strong> <strong>the</strong> restricted entry operator exposure6A Restricted Entry Interval (REI) is a time period within which specific restrictions must be met. Examples<strong>of</strong> <strong>the</strong> types <strong>of</strong> restrictions that may be imposed include use <strong>of</strong> PPE and RPE, entry is only allowed <strong>for</strong> certaintasks and <strong>for</strong> specified durations.Dichlorvos reassessment – application Page 50 <strong>of</strong> 436
assessment, as <strong>the</strong> Use Scenario includes operations such asreturning to traps to replace strips and inspection <strong>of</strong> traps. As aresult, ERMA New Zealand considers that <strong>the</strong> identified likelihoodsand magnitudes <strong>for</strong> operator exposure are <strong>the</strong> same <strong>for</strong> <strong>the</strong> operatorrestricted entry exposure risk. ERMA New Zealand considers that<strong>the</strong> magnitude <strong>of</strong> adverse effect posed to operators is minor tomajor. ERMA New Zealand considers that <strong>the</strong> likelihood <strong>of</strong> minorto major adverse effects occurring are very unlikely. The level <strong>of</strong>risk to <strong>the</strong> health <strong>of</strong> operators is <strong>the</strong>re<strong>for</strong>e negligible to low.Dichlorvos reassessment – application Page 51 <strong>of</strong> 436
Table 11.Summary <strong>of</strong> Restricted Entry Intervals (REI) and restrictions <strong>for</strong> use <strong>of</strong> dichlorvos-containing substances.Level <strong>of</strong> Risk Use Scenario PPE/RPE requirements REI ConditionsNegligible0 < RQ < 13, 4 hood/visor + overalls over long-sleeved shirt and longleggedtrousers + boots + gloves; at least a half-facerespirator (minimum specification A1P2)Cereals scouting.9, 10, 11, 12 hood/visor + overalls over long-sleeved shirt and longleggedtrousers + boots + gloves; full-face respirator(minimum specification A1P2) or air-hosehood/visor + overalls over long-sleeved shirt and longleggedtrousers + boots + gloveshat/goggles + overalls over long-sleeved shirt and longleggedtrousers + boots + gloves13, 14 hood/visor + overalls over long-sleeved shirt and longleggedtrousers + boots + gloves; full-face respirator(minimum specification A1P2) or air-hosehat/goggles + overalls over long-sleeved shirt and longleggedtrousers + boots + glovesRestricted entry is permittedafter at least 4 hours haselapsed since completion <strong>of</strong>application.Restricted entry is permittedafter at least 4 hours haselapsed since commencement<strong>of</strong> ventilation.Restricted entry is permittedafter at least 48 hours haselapsed since completion <strong>of</strong>application.Restricted entry is permittedafter at least 72 hours haselapsed since completion <strong>of</strong>application.Restricted entry is permittedafter at least 4 hours haselapsed since completion <strong>of</strong>application.Restricted entry is permittedafter at least 4 hours haselapsed since commencement<strong>of</strong> ventilation.<strong>for</strong> ventilation.< 30 minutes exposure.<strong>for</strong> tending.< 2h / day.<strong>for</strong> any tasks in mushroomhouses.< 2h / day.<strong>for</strong> tending and harvesting <strong>of</strong>glasshouse crops;<strong>for</strong> any tasks in mushroomhouses.<strong>for</strong> ventilation.< 30 minutes exposure.<strong>for</strong> tending/harvesting.< 1h / day.Dichlorvos reassessment – application Page 52 <strong>of</strong> 436
Nonnegligible1 < RQ < 10Nonnegligible(High)10 < RQ < ∞15, 16 hood/visor + overalls over long-sleeved shirt and longleggedtrousers + boots + gloves17, 18, 19, 20, 21,22, 23, 24, 25at least a half-face respirator (minimum specificationA1P2)no PPE or RPE requiredRestricted entry is permittedafter at least 72 hours haselapsed since completion <strong>of</strong>application.Restricted entry is permittedafter at least 4 hours haselapsed since commencement<strong>of</strong> ventilation.Restricted entry is permittedafter at least 72 hours haselapsed since completion <strong>of</strong>application.Entry permitted after 10 hourshas elapsed since completion<strong>of</strong> application.Entry permitted after 72 hoursafter commencement <strong>of</strong>ventilation <strong>for</strong> buildingstreated at 50 mg / m 3 .Entry permitted after 120hours after commencement <strong>of</strong>ventilation <strong>for</strong> buildingstreated at 150 mg / m 3 .<strong>for</strong> glasshouse tasks.<strong>for</strong> ventilation.< 30 minutes exposure.<strong>for</strong> tending and harvesting <strong>of</strong>glasshouse crops.<strong>for</strong> ventilation.< 30 minutes exposure.1, 2 HIGH RISK EVEN WITH HIGHEST LEVEL OF PPE3, 4 HIGH RISK EVEN WITH HIGHEST LEVEL OF PPE Vegetables, berries5, 6, 7, 8 HIGH RISK EVEN WITH HIGHEST LEVEL OF PPE26, 27, 28, 29, 30 Very high risk (no PPE). assumes no dissipation.Dichlorvos reassessment – application Page 53 <strong>of</strong> 436
4.4.4.3 Bystanders and children:The risks to bystanders (including children) from Use Scenarios 1to 8 are considered to be low.<strong>Application</strong> into enclosed spaces should only be carried out when<strong>the</strong> structure is clear <strong>of</strong> bystanders and appropriately sealed toprevent leakage. The risks to bystanders (including children) fromUse Scenarios 9 to 25 are, <strong>the</strong>re<strong>for</strong>e, considered to be low. Venting<strong>of</strong> treated structures (intentional or inadvertent) would result in apoint-source emissions that ERMA New Zealand considers will beadequately dispersed by air movement so that bystanders are notexposued to hazardous concentrations <strong>of</strong> dichlorvos.Exposure <strong>of</strong> children through contact with treated surfaces arisingfrom domestic use <strong>of</strong> dichlorvos-containing insecticide treatments(Use Scenarios 26 to 29) are estimated to reflect <strong>the</strong> bystanders atgreatest risk, and are considered by ERMA New Zealand to be veryhigh, given that <strong>the</strong> RQ values are > 880. Additionally, ERMANew Zealand has not been able to determine an REI <strong>for</strong> child entryinto treated areas.The exposures that children from contact with treated public areas(Use Scenario 30) are considered by ERMA New Zealand to bevery high, with an RQ <strong>of</strong> 86.ERMA New Zealand semi-quantitatively assessed <strong>the</strong> risk <strong>of</strong>exposure to operators arising from <strong>the</strong> use <strong>of</strong> dichlorvosimpregnatedinsecticide strips (Use Scenario 31). Bystanders couldbe exposed to dichlorvos if <strong>the</strong>y are close to an open trap, whichcould result from deliberate action or vandalism. ERMA NewZealand notes that <strong>the</strong>se traps are placed on private property at least1.3m above ground, are labelled and <strong>the</strong> property owner is fullyin<strong>for</strong>med, providing some level <strong>of</strong> security against interference,vandalism or access by small children. The magnitude <strong>of</strong> an effectis considered to be minimal to major, depending on <strong>the</strong> degree <strong>of</strong>exposure. The likelihood <strong>of</strong> a major adverse health effect to amember <strong>of</strong> <strong>the</strong> public is considered to be highly improbable. Thelikelihood <strong>of</strong> a minimal adverse health effect to a member <strong>of</strong> <strong>the</strong>public is considered to be unlikely at most. ERMA New Zealandconsiders <strong>the</strong> level <strong>of</strong> risk to bystanders and children is <strong>the</strong>re<strong>for</strong>enegligible to low.4.5 Summary <strong>of</strong> exposure risks to <strong>the</strong> environment and humanhealth.4.5.1 A summary <strong>of</strong> <strong>the</strong> level <strong>of</strong> risk to human health and <strong>the</strong> environment posed bydichlorvos-containing substances is detailed in Table 12.Dichlorvos reassessment – application Page 54 <strong>of</strong> 436
Table 12.LifecycleStageImport,manufacture,transport,storage ordisposalUse – aquatic,terrestrialenvironmentsand organismsUse – aquaticenvironmentUse –terrestrialenvironment(birds)Use –terrestrialenvironment(non-targetsoil dwellingorganisms)Use –terrestrialenvironment(non-targetterrestrialinvertebrates)Summary <strong>of</strong> <strong>the</strong> level <strong>of</strong> risk posed by use <strong>of</strong> dichlorvos-containing substances.UseScenarioPotentialadverse effect1 – 31 (all) Adverse acute orchronicenvironmenteffectsMagnitude <strong>of</strong>AdverseEffectsModerateLikelihood<strong>of</strong> AdverseEffectOccurringHighlyimprobableLevel <strong>of</strong> RiskNon-negligible(Negligible tolow)9 – 29, 31 Adverse acute or No risk posed.None.chronic30 environment Moderate Unlikely Non-negligibleeffects(Low)1 - 8 Adverse acute orchronicenvironmenteffects1 - 8 Adverse acute orchronicenvironmenteffects1 – 4, 7 - 8 Adverse acute orchronicenvironmenteffectsQuantitative assessmentindicates that use <strong>of</strong>dichlorvos:does not pose a significantrisk to aquatic plants andfish;poses a significant risk toaquatic invertebrates;is considered to pose norisk to sediment,groundwater or <strong>the</strong>marine environment.Quantitative assessmentindicates that use <strong>of</strong> dichlorvosposes a significant risk to birdsthat requires refinedassessment or management.Quantitative assessmentindicates that use <strong>of</strong> dichlorvosdoes not pose a significant riskto soil dwelling organismswithin or beyond <strong>the</strong>application area.5 - 6 Quantitative assessmentindicates that use <strong>of</strong> dichlorvosposea a significant risk to soildwelling organisms(earthworms) that requiresrefined assessment ormanagement.1 – 8 Adverse acute orchronicenvironmenteffectsQuantitative assessmentindicates that use <strong>of</strong> dichlorvosposes a significant (high) riskto non-target terrestrialinvertebrates that requiresrefined assessment ormanagement.Non-negligible(High)Non-negligibleNegligibleNon-negligibleNon-negligible(high)Dichlorvos reassessment – application Page 55 <strong>of</strong> 436
LifecycleStageImport,manufacture,transport,storage ordisposalUseScenarioUse - operator 9 - 10,Use –restricted entryPotentialadverse effect1 – 32 (All) Adverse acuteor chronichealth effects17 - 18Adverse acuteor chronichealth effectsMagnitude <strong>of</strong>AdverseEffectsModerateLikelihood<strong>of</strong> AdverseEffectOccurringHighlyimprobableQuantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significantrisk, unless appropriate PPE isused, and <strong>the</strong> number <strong>of</strong>cylinder changes are restrictedto a maximum <strong>of</strong> 1 per dayper operator.13 - 14 Quantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significantrisk, unless appropriate PPE isused, and o<strong>the</strong>r userestrictions are imposed.20 - 25 Quantitative assessmentindicates that use <strong>of</strong>dichlorvos does not pose asignificant risk if appropriatePPE is used, and o<strong>the</strong>r userestrictions are imposed.1 – 4,11 – 12,15 – 16,19,26 – 27,305 – 8,28 - 29Quantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significant(high) risk to operator health.Quantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significant(very high) risk to operatorhealth.31 Minor to major VeryUnlikely3 – 4(scouting incerealsonly),9-25Adverse acuteor chronichealth effectsQuantitative assessmentindicates that restricted entryinto application areas wheredichlorvos has been appliedposes a significant risk, unlessappropriate PPE is used ando<strong>the</strong>r restricted entryrestrictions are applied.Level <strong>of</strong> RiskNegligibleNon-negligibleNon-negligibleNon-negligibleNon-negligible(High)Non-negligible(Very high)Non-negligible(Negligible tolow)Non-negligibleDichlorvos reassessment – application Page 56 <strong>of</strong> 436
LifecycleStageUse –bystanderUseScenario1 – 2,3 – 4(vegetables,berries),5 - 8Potentialadverse effectMagnitude <strong>of</strong>AdverseEffectsLikelihood<strong>of</strong> AdverseEffectOccurringQuantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significant(very high) risk to <strong>the</strong> health<strong>of</strong> operators exposed totreated areas.26 - 30 Quantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significant(very high) risk to <strong>the</strong> health<strong>of</strong> children dermally exposedto treated surfaces.31 Minor to major VeryUnlikely1 -8 Adverse acuteor chronichealth effectsQuantitative assessmentindicates that exposure tosurfaces exposed to spray driftdoes not pose a significantrisk.Level <strong>of</strong> RiskNon-negligible(High)Non-negligible(Very high)Non-negligible(Negligible tolow)Negligible9 - 25 No risk posed. Negligible26 - 30 Quantitative assessmentindicates that use <strong>of</strong>dichlorvos poses a significant(very high) risk to <strong>the</strong> health<strong>of</strong> children dermally exposedto treated surfaces.31 Minimal tomajorHighlyImprobableNon-negligible(Very high)Non-negligible(Negligible tolow)Identification <strong>of</strong> beneficial effects (benefits)4.5.2 ERMA New Zealand did not identify any direct beneficial effects on human healthand safety from <strong>the</strong> use <strong>of</strong> dichlorvos.4.6 Society and communitiesIdentification <strong>of</strong> adverse effects on society and communities4.6.1 ERMA New Zealand has not been able to find any reports <strong>of</strong> public concern about<strong>the</strong> use <strong>of</strong> dichlorvos and <strong>the</strong>re<strong>for</strong>e has not identified any adverse effects on societyand communities, o<strong>the</strong>r than those associated with health and safety, from <strong>the</strong>continued use <strong>of</strong> <strong>the</strong>se substances. No adverse effects on society and community thatmight result from <strong>the</strong> unavailability <strong>of</strong> <strong>the</strong> substances have been identified.Dichlorvos reassessment – application Page 57 <strong>of</strong> 436
Identification <strong>of</strong> benefits to society and communities4.6.2 Benefits to society and community from <strong>the</strong> continued availability and non-plantprotection use <strong>of</strong> dichlorvos, based on its properties as an effective pesticide, areclosely allied to public health benefits. Social benefits from biosecurity use <strong>for</strong>detection <strong>of</strong> pests such as fruitfly are considered to be adequately addressed <strong>under</strong>effects on <strong>the</strong> market economy.4.6.3 ERMA New Zealand considers that <strong>the</strong> level <strong>of</strong> indirect benefit to public health (i.e.reduction in adverse effects through control <strong>of</strong> pests, such as cockroaches or fleas)through use <strong>of</strong> dichlorvos in large scale facilities, public buildings or public amenityareas (Use Scenarios 17 to 30) is estimated to be minimal, and is at least likely tooccur, resulting in a low level <strong>of</strong> positive effect.4.6.4 No potentially significant benefits or positive effects as a result <strong>of</strong> <strong>the</strong> unavailability<strong>of</strong> <strong>the</strong> substances have been identified.Overall evaluation <strong>of</strong> effects on society and communities4.6.5 ERMA New Zealand considers that <strong>the</strong>re are potentially significant positive effectson society and community from <strong>the</strong> continued availability and use <strong>of</strong> dichlorvos.4.6.6 ERMA New Zealand notes that <strong>the</strong>re may be additional social effects from <strong>the</strong> use <strong>of</strong>dichlorvos and invites submitters to provide any such in<strong>for</strong>mation <strong>the</strong>y might have tosupport <strong>the</strong> identification <strong>of</strong> such effects.4.7 The market economy4.7.1 In preparing this section, ERMA New Zealand consulted with users andcommissioned a report from Plant & Food Research on <strong>the</strong> horticultural use <strong>of</strong>dichlorvos in New Zealand and potential alternatives to its use (Plant & FoodResearch, 2009 - Appendix R).Identification <strong>of</strong> adverse effects on <strong>the</strong> market economy4.7.2 ERMA New Zealand did not identify any adverse effects on <strong>the</strong> market economyfrom <strong>the</strong> continued use <strong>of</strong> dichlorvos in horticulture, as long as <strong>the</strong>re is adherence to<strong>the</strong> relevant MRLs. Specific CODEX MRLs <strong>for</strong> dichlorvos have only been set <strong>for</strong>cereals, grains and mushrooms. MRLs <strong>for</strong> o<strong>the</strong>r uses <strong>the</strong>re<strong>for</strong>e use <strong>the</strong> default value<strong>of</strong> 0.1mg/kg.4.7.3 NZFSA MRLs have been set <strong>for</strong> three groups: vegetables, fruits, and cereals andgrains.4.7.4 Similarly <strong>the</strong>re are no obvious adverse effects on <strong>the</strong> market economy from use <strong>for</strong>public health purposes.4.7.5 If <strong>the</strong>re were to be a ban on <strong>the</strong> use <strong>of</strong> dichlorvos <strong>the</strong>n <strong>the</strong>re would be potentiallysignificant adverse effects on trade and biosecurity as a result <strong>of</strong> loss <strong>of</strong> benefits asdescribed below.Identification and assessment <strong>of</strong> beneficial effects (benefits) on <strong>the</strong> marketeconomy4.7.6 Through consultation with industry groups, ERMA New Zealand identifiedbeneficial effects on market economy as shown in Table 13. Each <strong>of</strong> <strong>the</strong>sebeneficial effects is evaluated in <strong>the</strong> following paragraphs.Dichlorvos reassessment – application Page 58 <strong>of</strong> 436
Table 13.Identification <strong>of</strong> beneficial effects on society and <strong>the</strong> economy fromimportation and use <strong>of</strong> dichlorvosBeneficial EffectMaintaining industry pr<strong>of</strong>itability in <strong>the</strong> horticulture sector (export and local markets)Benefits from use in <strong>the</strong> cymbidium growing industry and cut flower industryEconomic benefit associated with public health useCountering biosecurity incursions and potential effects on tradeMaintaining industry pr<strong>of</strong>itability in <strong>the</strong> horticulture section (export andlocal markets)4.7.7 Horticulture New Zealand has provided in<strong>for</strong>mation about use <strong>of</strong> dichlorvos in <strong>the</strong>capsicum and tamarillo industries and also <strong>for</strong> greenhouse use <strong>for</strong> tomatoes,capsicum and cucumber. This in<strong>for</strong>mation has been ga<strong>the</strong>red through consultationwith growers. Plant & Food Research (Plant & Food Research, 2009) has alsoprovided in<strong>for</strong>mation about <strong>the</strong> use <strong>of</strong> dichlorvos in horticulture. This report statesthat dichlorvos is registered <strong>for</strong> use on cloverseed, brassicas, cereals, vegetables,tamarillo, passionfruit, persimmon and berryfruit, as well as ornamentals,glasshouses and mushroom houses. In 2004 six sector groups were identified asusers <strong>of</strong> dichlorvos: blueberry, tamarillo, passionfruit, persimmon, asparagus andnerines/peonies/sandersonia.4.7.8 Growers have indicated that dichlorvos is important <strong>for</strong> maintaining <strong>the</strong>irpr<strong>of</strong>itability by providing an effective and cost efficient insecticide that ensures thatproduce is pest free and acceptable to <strong>the</strong> importing country.4.7.9 Dichlorvos is <strong>of</strong> particular value due to its volatility, which means that pesticidescontaining dichlorvos have short withholding periods, and can be used close toharvest, where o<strong>the</strong>r products might be precluded. This volatility also makes ituseful <strong>for</strong> use on overseas exports since <strong>the</strong> volatility results in low MRLs. It tendsto be used just once be<strong>for</strong>e harvest and usually only if an insect problem is identified(John Hicking pers. comm.).4.7.10 Dichlorvos is valued <strong>for</strong> its combination <strong>of</strong> physical and chemical properties,allowing its use where use <strong>of</strong> o<strong>the</strong>r insecticides would be less appropriate, but due toits broad activity spectrum is not used <strong>for</strong> integrated pest management (J. Hickingpers. comm.).4.7.11 Dichlorvos is considered an essential tool <strong>for</strong> capsicum growers and HorticultureNew Zealand states that all NZ capsicum growers use dichlorvos against thrips(sometimes on a weekly basis). There is no specific alternative. The value <strong>of</strong> <strong>the</strong>capsicum export crop is <strong>of</strong> <strong>the</strong> order <strong>of</strong> $33 million (approximately 15,000 tonnes).The local market is valued at approximately $35 million. The main benefit <strong>of</strong>dichlorvos is its volatility resulting in no residue detection after a very few days.In<strong>for</strong>mation provided by Horticulture New Zealand notes that dichlorvos is excellent<strong>for</strong> <strong>the</strong> capsicum export industry to Japan as no residue can be detected after threedays. New Zealand preharvest intervals vary from one day <strong>for</strong> asparagus to sevendays <strong>for</strong> tamarillo and passionfruit.4.7.12 Plant & Food Research (Plant & Food Research, 2009) did not report specifically onuse <strong>of</strong> dichlorvos <strong>for</strong> capsicum, but note that dichlorvos is used extensively inglasshouse vegetable production, moreso recently because <strong>of</strong> problems withdisruption <strong>of</strong> IPM programmes <strong>for</strong> tomatoes and capsicums.Dichlorvos reassessment – application Page 59 <strong>of</strong> 436
4.7.13 BOC gases provided in<strong>for</strong>mation about use on capsicum referring to <strong>the</strong> use <strong>of</strong>ArmourCrop (DDVP).4.7.14 Horticulture New Zealand notes that <strong>the</strong> tamarillo industry uses dichlorvos (Nuovos)against a range <strong>of</strong> pests including aphids, whitefly, caterpillars, mites and greenvegetable bug up to seven days be<strong>for</strong>e harvest. It is reportedly used about one yearin three in Northland, Bay <strong>of</strong> Plenty, Auckland, Taranaki and Gisborne, and while<strong>the</strong> amount used is unknown it is estimated as being less than 50 litres (<strong>of</strong> <strong>the</strong> madeup product). Alternatives are available, but dichlorvos has a shorter withholdingperiod. Two systemic products are available (ie need less application) but one <strong>of</strong><strong>the</strong>se products currently requires zero residue. The value <strong>of</strong> <strong>the</strong> export crop is just<strong>under</strong> $1million, and <strong>the</strong> local market around $1.4 million.4.7.15 Plant & Food Research (ibid) supports this in<strong>for</strong>mation, giving a slightly higherfigure (SNZ1.1m) <strong>for</strong> <strong>the</strong> value <strong>of</strong> <strong>the</strong> export crop. The main alternative product hasa 60 day preharvest interval <strong>for</strong> export fruit but only seven days <strong>for</strong> local fruit.Tomato/potato psyllid infestation in 2009 caused significant damage to tamarillocrops and dichlorvos is an important control option.4.7.16 Dichlorvos is used in greenhouses, mainly in <strong>the</strong> Auckland area, <strong>for</strong> production <strong>of</strong>tomatoes, capsicum and cucumber against thrips, whitefly and psyllid (Nuvos)between one and three times per year.4.7.17 Horticulture New Zealand states that dichlorvos is used in glasshouses as part <strong>of</strong> IPMprogrammes, ei<strong>the</strong>r at <strong>the</strong> end <strong>of</strong> cropping or, when IPM breaks down, to knockdownhigh pest populations to enable IPM to be re-established. Dichlorvos is <strong>of</strong>value because <strong>of</strong> its rapid dissipation enabling IPM to be reintroduced within 1 day<strong>of</strong> treatment. While <strong>the</strong>re are o<strong>the</strong>r means <strong>of</strong> controlling <strong>the</strong>se pests, if dichlorvoswere not available <strong>the</strong>n less IPM would be used. No value <strong>for</strong> <strong>the</strong> export crop hasbeen given. Horticulture New Zealand states that it is hard to estimate tonnage, butmakes an assessment <strong>of</strong> around 750kg <strong>of</strong> <strong>the</strong> active ingredient.4.7.18 The Plant & Food Research report (ibid) concurs with <strong>the</strong> Horticulture New Zealandevaluation noting particularly <strong>the</strong> adverse effect <strong>of</strong> <strong>the</strong> establishment <strong>of</strong>tomato/potato psyllid in New Zealand.4.7.19 Adria Crop Protection states that dichlorvos (Divap) may be used on berryfruit andvegetables <strong>for</strong> sucking insects, as well <strong>for</strong> public health purposes against flies andmosquitoes. They state that approximately 0.4 tonnes is used annually in Auckland,Hawkes Bay, Nelson/Marlborough and Canterbury.4.7.20 Plant & Food Research (ibid) report that fumigation <strong>of</strong> fresh asparagus withdichlorvos is ―standard practice <strong>for</strong> export asparagus‖. In 2008 <strong>the</strong> value <strong>of</strong> exportsales was $N2.5m. Currently <strong>the</strong> only alternative is methyl bromide, which is lesseffective and shortens shelf life because <strong>of</strong> <strong>the</strong> higher temperature required.4.7.21 Dichlorvos is registered <strong>for</strong> use on clover and vegetable seed and may be being used,but probably only at small levels as o<strong>the</strong>r products are available. Similarly Plant &Food Research (ibid) report that <strong>the</strong>re is little current use <strong>for</strong> cereal crops.Dichlorvos is also registered <strong>for</strong> use on mushrooms but is not currently used.4.7.22 Passionfruit is considered to be a minor crop, but Plant & Food Research (ibid) notethat because <strong>of</strong> this it is not able to fund trials <strong>of</strong> alternatives and <strong>the</strong>re are only twoinsecticides registered <strong>for</strong> use on passionfruit – dichlorvos and diazinon.4.7.23 In<strong>for</strong>mation received from industry indicates that dichlorvos contributes significantlyto <strong>the</strong> facilitation <strong>of</strong> trade in <strong>the</strong> horticulture industry, with particular reference totrade in tomatoes, capsicum and cucumber. While <strong>the</strong> value <strong>of</strong> total trade is high, <strong>the</strong>Dichlorvos reassessment – application Page 60 <strong>of</strong> 436
value that can be attributed to dichlorvos is unknown. ERMA New Zealand notesthat dichlorvos has specific benefits associated with its volatility, and that <strong>the</strong>re arelimited alternatives available at <strong>the</strong> present time, particularly <strong>for</strong> <strong>the</strong> minor cropssuch as persimmons, tamarillos and passionfruit. ERMA New Zealand cannotdetermine <strong>the</strong> amount <strong>of</strong> <strong>the</strong> value <strong>of</strong> <strong>the</strong> crops that can be attributed specifically to<strong>the</strong> use <strong>of</strong> dichlorvos, but accepts <strong>the</strong> view presented by Horticulture New Zealandand Plant & Food Research that it is potentially significant.4.7.24 It is interesting to note that Japan is moving towards not allowing import <strong>of</strong> freshasparagus that has been treated with dichlorvos (Plant & Food Research). Japan isNew Zealand‘s major market <strong>for</strong> vegetable products taking 34% by value <strong>of</strong>vegetable exports in 2009. Australia is <strong>the</strong> second biggest market at 23% (<strong>the</strong> UnitedStates <strong>of</strong> America is 3%). For fruit and vegetables <strong>the</strong> respective figures are 19%,14% (6%), with <strong>the</strong> EU taking 16%. If Japan were to extend this requirement too<strong>the</strong>r produce <strong>the</strong>n alternatives would need to be found quickly.4.7.25 Based on <strong>the</strong> in<strong>for</strong>mation provided by Horticulture New Zealand and Plant & FoodResearch, and noting <strong>the</strong> specific benefits provided by dichlorvos (e.g. rapiddissipation), ERMA New Zealand considers that a minimal benefit is at least likely,resulting in a low level <strong>of</strong> positive effect.Benefits from use in <strong>the</strong> cymbidium growing industry and cut flowerindustry4.7.26 In<strong>for</strong>mation provided by <strong>the</strong> Northland Cymbidium Growers Association based on anational survey <strong>of</strong> cymbidium growers suggests that dichlorvos is used in <strong>the</strong>cymbidium industry mainly in <strong>the</strong> Northland and Auckland regions. Some growersuse it regularly while o<strong>the</strong>rs use it as a chemical <strong>of</strong> last resort. Its volatility isvaluable here as well with relatively short restricted entry periods.4.7.27 The survey looked at <strong>the</strong> availability <strong>of</strong> alternatives, and growers were generally notaware <strong>of</strong> any product that would fill <strong>the</strong> particular function <strong>for</strong> which <strong>the</strong>y useddichlorvos. Respondents that considered alternatives showed preference <strong>for</strong> o<strong>the</strong>rorganophosphates in general, though no specific substances were identified.4.7.28 Cymbidiums have been consistent per<strong>for</strong>mers <strong>for</strong> a number <strong>of</strong> years. In 2003 <strong>the</strong>total value <strong>for</strong> exported cut flowers and foliage was just <strong>under</strong> $40m ($NZ38.5m <strong>for</strong><strong>the</strong> 2004-5 season). Plant & Food Research indicate that in 2009 this had risen toapproximately $NZ60m. In 2004-5 cymbidiums accounted <strong>for</strong> approximately half <strong>of</strong>this value, dropping to about one third ($NZ22m) in 2009. In 2005/6 Japan took51% <strong>of</strong> New Zealand flower exports and <strong>the</strong> United States 29%.4.7.29 Cymbidiums are <strong>the</strong>re<strong>for</strong>e a significant export crop. Currently dichlorvos is used <strong>for</strong>scale insect and mite control with its main value being that it can be used within oneday <strong>of</strong> harvesting or packing. Based on <strong>the</strong> in<strong>for</strong>mation provided about <strong>the</strong> use andvalue <strong>of</strong> dichlorvos to <strong>the</strong> cymbidium industry, ERMA New Zealand considers that aminimal benefit to <strong>the</strong> cut flower industry is unlikely thus leading to a negligiblebenefit. This does not mean that <strong>the</strong> export crop is not significant, but ra<strong>the</strong>r that <strong>the</strong>contribution <strong>of</strong> dichlorvos to cymbidium production in terms <strong>of</strong> a national benefit isnot significant.Economic benefit associated with public health use4.7.30 Dichlorvos is considered to be particularly important <strong>for</strong> insect pest control in <strong>the</strong>dairy industry where control <strong>of</strong> products is difficult because <strong>of</strong> large, structures andyear round operations with short periods available <strong>for</strong> insect control. ReportedlyDichlorvos reassessment – application Page 61 <strong>of</strong> 436
dichlorvos is used prior to startup <strong>of</strong> plants. Pest control programmes are generallycontracted out to companies such as Ecolab and Rentokil. In <strong>the</strong> past <strong>the</strong> dairyindustry used methyl bromide, but this is no longer available.4.7.31 Rentokil has indicated that dichlorvos is used to kill general insect and arachnid pests(Nuvos and Insectigas) and highlighted use in <strong>the</strong> dairy industry. While it is usedinfrequently it is considered vital <strong>for</strong> such purposes.4.7.32 The in<strong>for</strong>mation provided by <strong>the</strong> industry suggests that dichlorvos has replacedmethyl bromide.4.7.33 The use <strong>of</strong> dichlorvos <strong>for</strong> <strong>the</strong> fumigation <strong>of</strong> large scale facilities, and as a hygienetreatment to control fleas and cockroaches is a public health4.7.34 The economic benefit associated with this use could be measured in terms <strong>of</strong>downtime that would accrue if o<strong>the</strong>r products were used. The imposition <strong>of</strong>additional controls might also result in higher costs, but <strong>the</strong> extent <strong>of</strong> this cost is notknown. Since dichlorvos is used infrequently <strong>for</strong> this purpose ERMA New Zealandconcludes that any additional cost would be comparatively small and <strong>the</strong>re<strong>for</strong>e wouldnot be potentially significant in terms <strong>of</strong> effect on <strong>the</strong> market economy.Countering biosecurity incursions and potential effects on trade4.7.35 MAF-BNZ has provided in<strong>for</strong>mation about <strong>the</strong> use <strong>of</strong> dichlorvos <strong>for</strong> <strong>the</strong> NewZealand fruit fly surveillance programme (DDVP insecticide strips). Estimatedamount is around 15kg <strong>of</strong> <strong>the</strong> active ingredient per year. No current alternatives havebeen identified.4.7.36 Fruit Fly surveillance has been in place <strong>for</strong> more than 20 years and <strong>the</strong>re have beensix fruit fly incursions, <strong>the</strong> last in 1996.4.7.37 MAFBNZ has indicated that trade in horticulture produce is worth $2.2 billionannually to New Zealand. Ninety percent by value <strong>of</strong> this is fresh fruit andvegetables that could be affected by introduction <strong>of</strong> fruit flies.4.7.38 There are several thousand fruit fly species but a few are very economicallyimportant; Ceratistis spp, e.g. Mediterranean and South African fruit flies (als<strong>of</strong>ound in Hawaii, Central and South American, Western Australia), Bactrocera spp ,e.g. Queensland fruit fly, Oriental fruit fly, Pacific Island fruit fly, melon fly (allfound in various temperate and tropical regions), Anastrepha spp, e.g. Central andSouth American fruit fly , Rhagoletis spp found in North America and Europe. Thelures used in <strong>the</strong> fruit fly traps in New Zealand are primarily targeting <strong>the</strong>Mediterranean, Oriental and Queensland fruit flies, and o<strong>the</strong>r lure responsive species.The Mediterranean fruit fly is known to attack more than 250 different fruit andvegetables including avocado, citrus, feijoa, grape, peppers, persimmon, pip fruit,stone fruit and walnut and is ranked as <strong>the</strong> world‘s most economically damaging fruitfly.4.7.39 In its application to ERMA New Zealand <strong>for</strong> approval <strong>for</strong> DDVP fruit fly detectionstrips containing dichlorvos (HSR04011), MAF stated that <strong>the</strong> fruit fly monitoringprogramme provides economic benefit to New Zealand through assurance tooverseas trading partners that New Zealand produce is free <strong>of</strong> fruit fly infestation.This provides New Zealand exporters with an advantage over o<strong>the</strong>r countriesexporting <strong>the</strong> same crops.4.7.40 In <strong>the</strong> event <strong>of</strong> an outbreak some markets (e.g. Japan) would become inaccessiblewhile o<strong>the</strong>r markets would require produce to be treated (by heat or using pesticides),which would add cost and might produce market access problems. During <strong>the</strong> 1996Dichlorvos reassessment – application Page 62 <strong>of</strong> 436
outbreak, MAF‘s ability to demonstrate <strong>the</strong> effectiveness <strong>of</strong> <strong>the</strong> surveillanceprogramme meant that barriers to New Zealand‘s trade were substantially reduced.4.7.41 With New Zealand remaining fruit fly free <strong>the</strong> horticultural industry enjoys somecompetitive advantages. Production costs are reduced (no additional physical orchemical treatments to produce, no added insecticide treatments to crops). Productquality can maintain a high standard; fruit fly attack causes <strong>the</strong> premature drop <strong>of</strong>fruit as well as making fruit inedible (maggots in fruit).4.7.42 The most recent fruit fly detection occurred in 1996 when two Mediterranean fruitflies were trapped in Mt Roskill. All flies located as part <strong>of</strong> <strong>the</strong> subsequenteradication campaign were detected within 200 m <strong>of</strong> <strong>the</strong> original identification site.The reported cost <strong>of</strong> eradication and monitoring to confirm <strong>the</strong> success <strong>of</strong> <strong>the</strong>programme is $6 million.4.7.43 The cost <strong>of</strong> <strong>the</strong> programme is not insignificant, however it is considered <strong>the</strong>economic benefit to New Zealand horticultural industry and international tradejustifies <strong>the</strong> investment in this biosecurity programme.4.7.44 Without an effective active and rapid surveillance programme to detect fruit flypopulations rapidly, should <strong>the</strong>se pests become established it is anticipated thateradication would cost $100 million. There would be additional costs associatedwith <strong>the</strong> impact on existing exports (see above).4.7.45 Early detection <strong>of</strong> an unwanted pest such as <strong>the</strong> fruit fly means that a population canbe eradicated more easily than would be <strong>the</strong> case when <strong>the</strong> pest becomes established.This means eradication is faster and at a lesser cost.4.7.46 With people and goods passing through New Zealand borders every day fromregions where fruit fly is well-established, <strong>the</strong> likelihood <strong>of</strong> a possible incursion isrelatively high.4.7.47 Taking into account <strong>the</strong> high cost <strong>of</strong> eradication <strong>of</strong> pests as well as <strong>the</strong> likelihood <strong>of</strong>incursion, ERMA New Zealand considers that a moderate benefit is unlikely tolikely, resulting in a low to medium level <strong>of</strong> positive effect.Overall evaluation <strong>of</strong> effects on <strong>the</strong> market economy4.7.48 No adverse effects on <strong>the</strong> market economy have been identified <strong>for</strong> ei<strong>the</strong>r <strong>the</strong>baseline Outcome Scenario (continued use with current controls) or OutcomeScenario (b) (continued use with revised controls). This is primarily becausepotential adverse effects on trade are managed commercially by adherence toCODEX MRLs, and <strong>the</strong> requirements <strong>of</strong> export markets.4.7.49 With respect to <strong>the</strong> Cymbidium and cut flower industries <strong>the</strong> conclusion reachedabove it that <strong>the</strong> level <strong>of</strong> benefit to <strong>the</strong> overall market economy from use <strong>of</strong>dichlorvos is <strong>the</strong>se industries is negligible, based on <strong>the</strong> conclusions that while <strong>the</strong>export crop <strong>of</strong> cymbidium is significant to that industry, <strong>the</strong> contribution <strong>of</strong>dichlorvos to cymbidium production in terms <strong>of</strong> a national benefit is not significant.ERMA New Zealand would value fur<strong>the</strong>r in<strong>for</strong>mation in this area. However, since<strong>the</strong>re are no adverse effects on <strong>the</strong> market economy from <strong>the</strong> continued use <strong>of</strong>dichlorvos, <strong>the</strong> positive effects (albeit small) must be considered to outweigh <strong>the</strong>adverse effects <strong>for</strong> both continued use with existing controls and continued use withrevised controls.4.7.50 Similarly, while <strong>the</strong> level <strong>of</strong> economic benefit from <strong>the</strong> use <strong>of</strong> dichlorvos <strong>for</strong>fumigation <strong>of</strong> large structures (public health use) is not considered to be significant,<strong>the</strong> positive effects <strong>of</strong> its use outweigh <strong>the</strong> adverse effects <strong>for</strong> both OutcomeDichlorvos reassessment – application Page 63 <strong>of</strong> 436
Scenarios (a) and (b). There do not appear to be any effective alternatives currentlyavailable. Thus <strong>the</strong> loss <strong>of</strong> <strong>the</strong> product would result in potential benefits that mayarise from its availability not being realised, which is classed as an absence <strong>of</strong> benefit(i.e. none), ra<strong>the</strong>r than an adverse effect. ERMA New Zealand invites submitters toprovide fur<strong>the</strong>r in<strong>for</strong>mation.4.7.51 In terms <strong>of</strong> effects on trade with respect <strong>of</strong> <strong>the</strong> use <strong>of</strong> dichlorvos <strong>for</strong> counteringbiosecurity incursions, <strong>the</strong> level <strong>of</strong> benefit on trade has been assessed low tomedium. Since <strong>the</strong>re are no adverse effects associated with this use, <strong>the</strong> positiveeffects outweigh <strong>the</strong> adverse effects <strong>for</strong> both Outcome Scenarios (a) and (b). Ifdichlorvos were unavailable (Outcome Scenario (c)), loss <strong>of</strong> <strong>the</strong> product would resultin potential benefits arising from its availability not being realised, an absence <strong>of</strong>benefit (i.e. none), ra<strong>the</strong>r than an adverse effect.4.7.52 In terms <strong>of</strong> maintaining industry pr<strong>of</strong>itability in <strong>the</strong> horticulture sector, <strong>the</strong> two areaswhere effects could be expected to be potentially significant are <strong>the</strong> asparagusindustry, and glasshouse production <strong>of</strong> tomatoes, capsicum and cucumber. However,while <strong>the</strong> volatility <strong>of</strong> dichlorvos means that residues cannot be detected after a shortnumber <strong>of</strong> days, Japan, which is a significant market, is moving towards notaccepting product that has had dichlorvos used on it. ERMA New Zealand wouldwelcome fur<strong>the</strong>r in<strong>for</strong>mation about <strong>the</strong> possible ban and <strong>the</strong> value <strong>of</strong> product going toJapan. ERMA New Zealand has concluded that <strong>the</strong> overall benefit <strong>of</strong> dichlorvos to<strong>the</strong> horticulture sector, and specifically <strong>the</strong> glasshouse production <strong>of</strong> tomatoes,capsicum and cucumber are at least low, and <strong>the</strong>re<strong>for</strong>e <strong>the</strong> positive effects outweigh<strong>the</strong> adverse effects <strong>for</strong> Outcome Scenarios (a) and (b). If dichlorvos wereunavailable (Outcome Scenario (c)), loss <strong>of</strong> <strong>the</strong> product would result in potentialbenefits arising from its availability not being realised, an absence <strong>of</strong> benefit (i.e.none), ra<strong>the</strong>r than an adverse effect.4.7.53 These assessments are based on limited in<strong>for</strong>mation, and ERMA New Zealand hasendeavoured to be conservative in terms <strong>of</strong> estimating <strong>the</strong> level <strong>of</strong> benefit and toadopt a risk averse position in terms <strong>of</strong> estimating <strong>the</strong> level <strong>of</strong> risk/cost.4.8 Māori interests and concernsRelationship <strong>of</strong> Māori to <strong>the</strong> environment4.8.1 Iwi/Māori interests have not been specifically consulted in <strong>the</strong> preparation <strong>of</strong> thisapplication. However ERMA New Zealand has received clear messages at severalhui with iwi/Māori resource managers that unless substances provide clear benefits tooutweigh potential risk, <strong>the</strong>y generally oppose <strong>the</strong> ongoing use <strong>of</strong> highly hazardoussubstances. It is likely that, in <strong>the</strong> absence <strong>of</strong> fur<strong>the</strong>r in<strong>for</strong>mation regarding benefits,submissions from Māori would seek <strong>the</strong> revocation <strong>of</strong> <strong>the</strong> approvals <strong>for</strong> dichlorvosand its approved <strong>for</strong>mulations.Treaty <strong>of</strong> Waitangi4.8.2 Section 8 <strong>of</strong> <strong>the</strong> Act requires <strong>the</strong> Authority, when considering applications, to takeinto account <strong>the</strong> principles <strong>of</strong> <strong>the</strong> Treaty <strong>of</strong> Waitangi. Of particular relevance to thisapplication is <strong>the</strong> principle <strong>of</strong> active protection affirmed by <strong>the</strong> Court <strong>of</strong> Appeal in<strong>the</strong> Lands case (1987).4.8.3 This principle refers to <strong>the</strong> Crown‘s obligation to take positive steps to ensure thatMāori interests are protected, and to consider <strong>the</strong>m in line with <strong>the</strong> interestsguaranteed to Māori in Article II <strong>of</strong> <strong>the</strong> Treaty. Specifically <strong>the</strong> Court noted that ―…Dichlorvos reassessment – application Page 64 <strong>of</strong> 436
<strong>the</strong> duty <strong>of</strong> <strong>the</strong> Crown is not merely passive but extends to active protection <strong>of</strong> Maoripeople in <strong>the</strong> use <strong>of</strong> <strong>the</strong>ir lands and waters to <strong>the</strong> fullest extent practicable‖.4.8.4 Taking into account <strong>the</strong> principle <strong>of</strong> active protection requires this application toprovide sufficient evidence to show that <strong>the</strong> use <strong>of</strong> dichlorvos and its approved<strong>for</strong>mulations pose no risk <strong>of</strong> adverse effects to native/endemic species and/or o<strong>the</strong>rtaonga species, ecosystems and traditional Māori values, practices, health and wellbeing.Having considered <strong>the</strong> in<strong>for</strong>mation available in relation to <strong>the</strong> adverse effectsnoted above, ERMA New Zealand considers that retaining <strong>the</strong> current approvals <strong>for</strong>dichlorvos and its <strong>for</strong>mulations would be inconsistent with <strong>the</strong> principle <strong>of</strong> activeprotection.4.9 International obligations4.9.1 ERMA New Zealand has not identified any international obligations regardingdichlorvos.4.9.2 The use <strong>of</strong> dichlorvos and <strong>for</strong>mulations has been reviewed by several overseasjurisdictions (Appendix L). These reviews do not pose an obligation on NewZealand but are relevant to consideration <strong>of</strong> risks and pertinent risk managementmeasures.Dichlorvos reassessment – application Page 65 <strong>of</strong> 436
SECTION 5– LIKELY EFFECTS OF DICHLORVOS BEINGUNAVAILABLE5.1 Introduction5.1.1 ERMA New Zealand considered alternative scenarios that might arise if <strong>the</strong> use <strong>of</strong>dichlorvos was restricted or prevented. In particular, <strong>the</strong> availability <strong>of</strong> alternativepesticides was considered. It is noted that <strong>the</strong> list <strong>of</strong> alternatives identified may notbe a complete representation <strong>of</strong> all available alternatives, and ERMA New Zealandwelcomes additional in<strong>for</strong>mation on potential alternative substances.5.1.2 Detailed in<strong>for</strong>mation on <strong>the</strong> comparability <strong>of</strong> <strong>the</strong> alternative products has not beenga<strong>the</strong>red, in particular:relative efficacy;<strong>the</strong> research required to determine if <strong>the</strong>y are indeed suitable alternatives;comparability <strong>of</strong> properties <strong>for</strong> which dichlorvos is valued, rapid knockdown,rapid dissipation, broad spectrum activity, suitability <strong>for</strong> fogging;<strong>for</strong> plant protection products, compatibility with IPM.5.1.3 It is noted that restricting <strong>the</strong> suite <strong>of</strong> pesticides available may lead to a reducedability to manage pest resistance.5.1.4 Overseas, <strong>the</strong> use <strong>of</strong> dichlorvos as a plant protection product is no longer permitted,or it is proposed that it be terminated. Reviews leading to <strong>the</strong>se restrictions do notdiscuss <strong>the</strong> availability <strong>of</strong> alternative products (APVMA, 2008; USEPA, 2006;PMRA, 2008; EU, 2003, 2006, 2007), but <strong>the</strong> pests that are managed by dichlorvosin New Zealand are present overseas and overseas growers must have alternativemeans <strong>of</strong> managing <strong>the</strong>m. In <strong>the</strong> Ne<strong>the</strong>rlands, <strong>for</strong> example, when dichlorvos wasremoved from <strong>the</strong> market, greenhouse growers used methiocarb, spinosad, abamectinand methomyl to control thrips, imidacloprid, acetamiprid, pymetrozine, flonicamidand thiacloprid to control whitefly and aphids (van der Staaij pers. comm.),pyrethrum and beneficials to clean out greenhouses (Kerklaan pers. comm.). Noapplication <strong>for</strong> approval <strong>of</strong> flonicamid (active ingredient or <strong>for</strong>mulations) or <strong>of</strong>acetamiprid <strong>for</strong>mulations has been made in New Zealand but <strong>the</strong> o<strong>the</strong>r pesticidesused in <strong>the</strong> Ne<strong>the</strong>rlands are approved.5.1.5 Dichlorvos is used more widely in non-agricultural (plant protection) situationsoverseas (Section 3).Availability <strong>of</strong> alternative plant protection products5.1.6 Users have identified some alternative products, but none with all <strong>the</strong> properties thatmake dichlorvos valuable in many applications, i.e.:Rapid knockdown;Short pre-harvest intervals;Broad-spectrum activity;Suitability <strong>for</strong> fogging and resultant good penetration.5.1.7 Users commented on alternatives as follows:Dichlorvos reassessment – application Page 66 <strong>of</strong> 436
5.1.7.1 J. Hicking stated that dichlorvos EC tends to be used once, shortly be<strong>for</strong>eharvest and only if an insect problem is identified, its volatility makes itideal <strong>under</strong> <strong>the</strong>se conditions. At o<strong>the</strong>r times, o<strong>the</strong>r pesticides are used,<strong>for</strong> example, syn<strong>the</strong>tic pyrethroids including α-cypermethrin anddeltamethrin and organophosphates including diazinon and chlorpyrifos.5.1.7.2 Horticulture New Zealand suggested Chess (pymetrozine) and Calypso(thiacloprid) are used by tamarillo growers, Confidor (imidacloprid),Chess (pymetrozine), Ovation (bupr<strong>of</strong>ezin), Lannate (methomyl), Mavrik(tau-fluvalinate) and Avid (abamectin) by glasshouse growers.Horticulture New Zealand add that <strong>the</strong> last three <strong>of</strong> <strong>the</strong>se products are notcompatible with IPM. If IPM is not used, weekly sprays alternatingLannate and Confidor are used. They suggest that if dichlorvos was notavailable glasshouse growers would use less IPM.5.1.7.3 NCGA indicated that syne<strong>the</strong>tic pyrethroids can be used to control twospottedmite (Tetranychus urticae), but <strong>the</strong>ir use is problematic to somegrowers because it is difficult to establish <strong>the</strong> predatory mitePhytoseiulus persimilis <strong>for</strong> some time after treatment. However, P.persimilis is used only <strong>for</strong> a limited time window and use <strong>of</strong> IPM is givenlow priority by <strong>the</strong> industry as a whole.5.1.7.4 Horticulture New Zealand indicates that Movento (spirotetramat) is anew product that will be <strong>of</strong> value to glasshouse growers (crop and pestnot specified) and Oberon (spiromesifen) would also be <strong>of</strong> value. Thereare beneficial insects available overseas, but not available in NZ.5.1.7.5 Horticulture New Zealand capsicum growers say no alternatives againstthrips except Match (lufenuron) & Success (spinosad) used toge<strong>the</strong>r anddichlorvos – none <strong>of</strong> <strong>the</strong> old organophosphate chemistry is effective.5.1.7.6 Biosecurity NZ stated in application HSR04011: In <strong>the</strong> past malathionhas been used in traps as an insecticide. However this required injectingliquid malathion into dental wicks. This was messy and potentiallydirectly exposes contractors to higher concentrations <strong>of</strong> anorganophosphorus insecticide, more chance <strong>of</strong> contamination <strong>of</strong> trapcomponents and a higher risk <strong>of</strong> variability between traps.5.1.7.7 Sections <strong>of</strong> <strong>the</strong> report from Plant & Food (Appendix N) that discussalternatives can be summarized:5.1.7.7.1 Persimmon:Dichlorvos is valued as pre-harvest treatment to controlpassenger pests such as oribatid mites. Physical controlsand syn<strong>the</strong>tic pyrethroids and pyrethrum have been trialedbut were ineffective in controlling <strong>the</strong>se passenger pests.There are no alternatives that are effective in controlling<strong>the</strong> range <strong>of</strong> pests in persimmons with rapid decline inresidues;5.1.7.7.2 Passionfruit:Dichlorvos is used to treat thrips, which get <strong>under</strong> <strong>the</strong> skincausing ‗pimpling‘. Diazinon and dichlorvos are <strong>the</strong> onlyinsecticides registered <strong>for</strong> use on passionfruit. Spinosadmight be effective, but is not registered, and given <strong>the</strong> size<strong>of</strong> <strong>the</strong> industry, growers are unable to fund <strong>the</strong> trialsneeded;Dichlorvos reassessment – application Page 67 <strong>of</strong> 436
5.1.7.7.3 Tamarillos:A range <strong>of</strong> insecticides is registered <strong>for</strong> use on tamarillo,including carbaryl, acephate, diazinon, pymetrozine,deltamethrin, taufluvalinate, bupr<strong>of</strong>ezin and dichlorvos.Tomato/potato psyllid is a new and particularly damagingpest, which killed up to 60% <strong>of</strong> trees in 2009. Severalproducts, including some not registered on tamarillo, havebeen tested to see if <strong>the</strong>y will control tomato/potatopsyllid, including thiacloprid, Success Naturalyte,spiromesifen and chlorotraniliprole. Dichlorvos,deltamethrin and abamectin have shown best control, butdichlorvos is preferred due to its short pre-harvest interval;5.1.7.7.4 Berryfruits:The main pests are bronze beetle on blueberries andCarpophilus beetle on strawberries both <strong>of</strong> which becomemore important as more persistent organophosphates areremoved from production programmes. Dichlorvos hasproved effective and its short pre-harvest interval is alsoan attraction. No alternative products have beenidentified, but it is not clear how much research has beenper<strong>for</strong>med;5.1.7.7.5 Ornamentals and cut flower production:Dichlorvos is used in ornamental and cut flowerproduction, particularly Cymbidium production. IPM isused <strong>for</strong> two-spotted mite (T. urticae) control anddichlorvos is a part <strong>of</strong> this management system because<strong>the</strong> eggs <strong>of</strong> <strong>the</strong> predatory mite, Phytoseiulus persimillis arenot affected. In addition, <strong>the</strong> fumigant action <strong>of</strong>dichlorvos means that blooms do not get wet, which cancause disease. There is interest in using dichlorvos <strong>for</strong>lightbrown apple moth control in cut flowers and foliage.No alternative products were identified;5.1.7.7.6 Glasshouse vegetables:Dichlorvos is used fairly extensively because it can beused in a fogger which is quicker than applying a wetspray. It is used <strong>for</strong> clean-up <strong>of</strong> glasshouses and to knockdown pests prior to introduction <strong>of</strong> bees or predator mites.There are no alternative products that can be used infogging equipment. Tomato/potato psyllids establishmentin New Zealand is a particular problem <strong>for</strong> <strong>the</strong> glasshousetomato and capsicum industry and dichlorvos is one <strong>of</strong> 25pesticides listed <strong>for</strong> control <strong>of</strong> this pest, most <strong>of</strong> whichhave pre-harvest intervals as short as <strong>the</strong> 3 day periodapplicable to dichlorvos (Horticulture NZ, 2008);5.1.7.7.7 Mushrooms:Dichlorvos is not currently used, but deregistration wouldleave very few insecticides registered <strong>for</strong> use onmushrooms. Biological control agents, Hypoaspsaculeifer and Steinemema feltiae and fipronil anddiflubenzuron are registered alternatives, althoughdichlorvos could be used against a wider range <strong>of</strong> pests;Dichlorvos reassessment – application Page 68 <strong>of</strong> 436
Table 14. Comparative <strong>of</strong> hazard classifications <strong>of</strong> o<strong>the</strong>r insecticide active ingredients applied to products on which dichlorvos is used.Crop Pest Active ingredient Preharvestperiod(days)Persimmon Passenger pestssuch as oribatid ChlorpyrifosmitesDiazinonPassionfruitDichlorvos reassessment – application Page 70 <strong>of</strong> 436Status 6.1 6.1 6.1 6.6 6.7 6.8 6.9 9.1 9.2 9.3 9.4 BioaccumulativeDichlorvos 2 6.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No YesCarbarylTrialed butineffectiveUnspecified Permethrin 7 May be 6.1C No No No No No 6.9B 9.1A ND 9.3B 9.4A Yes YesPirimiphos-methyl 7withdrawndue towithdrawal 6.1E 6.1D ND No ND 6.8B 6.9A 9.1A ND 9.3A 9.4A Yes N<strong>of</strong>rom NZKiwifruitCropProtectionProgrammeChlorpyrifos ? 6.1C 6.1B 6.1D No ND No 6.9A 9.1A 9.2B 9.3A 9.4A Yes NoAphidsCaterpillarsWhiteflyAphidsCaterpillarsWhiteflyGrass grubbeetleLeafroller,ThripsCherry slugN/ARapidbiodegradationUnspecified broadspectruminsecticidesNANDDichlorvos 2 6.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No YesDiazinon 14 Registered 6.1C 6.1C 6.1D ND No 6.8B 6.9A 9.1A 9.2D 9.3A 9.4A No NoSpinosad 3 Notregistered <strong>for</strong>passionfruit,registered <strong>for</strong>summerfruitMaldisonRecentlywithdrawnfrom NZ6.1E No No ND ND ND 6.9B 9.1A No No 9.4A No No6.1D 6.1E 6.1E ND No 6.8B 6.9A 9.1A ND 9.3B 9.4A No No
Crop Pest Active ingredient Preharvestperiod(days)marketStatus 6.1 6.1 6.1 6.6 6.7 6.8 6.9 9.1 9.2 9.3 9.4 BioaccumulativeRapidbiodegradationTamarillosAphidsCaterpillars,WhiteflySome control <strong>of</strong>tomato/potatopsyllid.Tomato/potatopsyllidDichlorvos 7 6.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No YesDeltamethrin 7 PHI 60 days<strong>for</strong> exportAbamectin ? Not available<strong>for</strong> exportcropThiaclopridTrialed butPymetrozineineffectiveSpinosadBupr<strong>of</strong>ezinSpriomesifenChloantraniliprole6.1B 6.1C 6.1C No ND No 6.9A 9.1A 9.2C 9.3A 9.4A Yes No6.1B ND ND No No 6.8B 6.9A 9.1A 9.2A 9.3A 9.4A No NoCaterpillar Carbaryl 1 6.1C 6.1D ND No 6.7B No 6.9B 9.1A 9.2B 9.3B 9.4A No NoGrass grubbeetleLeafrollerAphids Acephate 14 6.1D No ND No 6.7B 6.8B 6.9A 9.1D No 9.3B 9.4A No YesCaterpillarsGrass grubbeetleAphids Diazinon 14 6.1C 6.1C 6.1D ND No 6.8B 6.9A 9.1A 9.2D 9.3A 9.4A No NoCaterpillarsGrass grubbeetleAphids, Pymetrozine 14 No ND ND No ND No 6.9B 9.1C No No No No NowhiteflyWhitefly Deltamethrin 7 PHI 60 days 6.1B 6.1C 6.1C No ND No 6.9A 9.1A 9.2C 9.3A 9.4A Yes NoN/ADichlorvos reassessment – application Page 71 <strong>of</strong> 436
Crop Pest Active ingredient Preharvestperiod(days)Grass grubStatus 6.1 6.1 6.1 6.6 6.7 6.8 6.9 9.1 9.2 9.3 9.4 Bioaccumulative<strong>for</strong> exportGreen peach Taufluvalinate 60 6.1C No ND No ND No 6.9B 9.1A No 9.3B 9.4B No NoaphidWhiteflyWhitefly Bupr<strong>of</strong>ezin 7 6.1D No ND No ND ND 6.9B 9.1D No 9.3C ND Yes NoBerryfruits Bronze beetle Unspecified broadCarpophilus spectrumbeetleinsecticidesOrnamentals Mites & insects Unspecified broadand cutspectrumflowers,insecticidesincludingCymbidiumorchidsGlasshousevegetablesVariousincludingwhitefly &aphids,tomato/potatopsylllidNDNDRapidbiodegradationDichlorvos 36.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No Yes(toms)3(caps)Methomyl 26.1B No 6.1B No No No 6.9B 9.1A 9.2A 9.3A 9.4A No No(toms)2(caps)Oxamyl ? 6.1A 6.1E 6.1B No No No 6.9B 9.1A 9.2A 9.3A 9.4A No NoPirimicarb 3(toms)? (caps)Diazinon 3(toms)14(caps)Maldison 3(toms)3(caps)6.1C ND 6.1B ND ND No 6.9B 9.1A ND 9.3A 9.4C No No6.1C 6.1C 6.1D ND No 6.8B 6.9A 9.1A 9.2D 9.3A 9.4A No No6.1D 6.1E 6.1E ND No 6.8B 6.9A 9.1A ND 9.3B 9.4A No NoDichlorvos reassessment – application Page 72 <strong>of</strong> 436
RapidbiodegradationCrop Pest Active ingredient Preharvestperiod(days)Methamidophos 3(toms)? (caps)Pirimiphos-methyl 3(toms)3(caps)Alphacypermethrin3(toms)Deltamethrin 3Lambdacyhalothrin(toms)3(toms)? (caps)Taufluvalinate 3(toms)? (caps)Status 6.1 6.1 6.1 6.6 6.7 6.8 6.9 9.1 9.2 9.3 9.4 Bioaccumulative6.1B 6.1B 6.1B ND No ND 6.9A 9.1A 9.2B 9.3A 9.4A No Yes6.1E 6.1D ND No ND 6.8B 6.9A 9.1A ND 9.3A 9.4A Yes No6.1B ND ND No ND No 6.9B 9.1A No 9.3B 9.4A No No6.1B 6.1C 6.1C No ND No 6.9A 9.1A 9.2C 9.3A 9.4A Yes No6.1D ND ND No ND ND ND 9.1A ND ND ND Yes Yes6.1C No ND No ND No 6.9B 9.1A No 9.3B 9.4B No NoImidacloprid ? 6.1C No No No No No 6.9B 9.1A 9.2A 9.3A 9.4A No NoThiacloprid ? 6.1D No 6.1D No 6.7B 6.8B 6.9B 9.1A 9.2C 9.3B 9.4C No Nothiamethoxam ? 6.1D No No No No ND 6.9B 9.1B No 9.3C 9.4A No NoSpinetoram ? No No No No No No 6.9B 9.1A No No 9.4A No NoSpinosad 36.1E No No ND ND ND 6.9B 9.1A No No 9.4A No No(toms)? (caps)Abamectin 36.1B ND ND No No 6.8B 6.9A 9.1A 9.2A 9.3A 9.4A No No(toms)? (caps)Pymetrozine 3No ND ND No ND No 6.9B 9.1C No No No No No(toms)? (caps)Novaluron ? No No No No ND No 6.9B 9.1A No No No Yes NoBupr<strong>of</strong>ezin 3(toms)3(caps)6.1D No ND No ND ND 6.9B 9.1D No 9.3C ND Yes NoDichlorvos reassessment – application Page 73 <strong>of</strong> 436
Crop Pest Active ingredient Preharvestperiod(days)FieldvegetablesAsparagusMushroomsDichlorvos reassessment – application Page 74 <strong>of</strong> 436Status 6.1 6.1 6.1 6.6 6.7 6.8 6.9 9.1 9.2 9.3 9.4 BioaccumulativeFenpyroximate ? 6.1C No 6.1B ND No ND 6.9B 9.1A 9.2C 9.3B ND Yes NoRapidbiodegradationSpiromesifen 1No No No No No No 6.9B 9.1A No No No Yes Yes(toms)1(caps)Spirotetramat ? No No No No No 6.8B No 9.1A No No No No NoChlorantraniliprole ? No No No no ND No No 9.1A No No No No NoThrips Lufenuron ? (caps) No No No ND ND ND 6.9B 9.1A No No No Yes NoUnspecifiedAphidsCaterpillarsMitesThripsSpinosad ? (caps) 6.1E No No ND ND ND 6.9B 9.1A No No 9.4A No NoMethiocarb 6.1B 6.1C 6.1B No No No 6.9B 9.1A 9.2A 9.3A 9.4A No YesAbamectin 6.1B ND ND No No 6.8B 6.9A 9.1A 9.2A 9.3A 9.4A No NoMethomyl 6.1B No 6.1B No No No 6.9B 9.1A 9.2A 9.3A 9.4A No NoUnspecified broadNDspectruminsecticidesDichlorvos 1 6.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No YesGarden weevil Esfenvalerate 1 6.1C No 6.1B No No No 6.9A 9.1A ND 9.3B 9.4A Yes YesPhorid & sciaridfliesMitesAphidsCaterpillarsThripsWhiteflySciarid, cecidand phorid fliesDichlorvos 3 6.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No YesFipronil 14 6.1C 6.1C 6.1B No ND ND 6.9A 9.1A ND 9.3A 9.4A Yes NoSciarid flies Diflubenzuron ? No No No No ND NO 6.9B 9.1A No No No No NoFruit fly monitoring Dichlorvos 3 6.1B 6.1B 6.1B 6.6B 6.7B No 6.9A 9.1A 9.2D 9.3A 9.4A No YesDiazinon - 6.1C 6.1C 6.1D ND No 6.8B 6.9A 9.1A 9.2D 9.3A 9.4A No NoMaldison - 6.1D 6.1E 6.1E ND No 6.8B 6.9A 9.1A ND 9.3B 9.4A No No
5.2.5 ERMA New Zealand identified <strong>the</strong> following sources <strong>of</strong> uncertainty in per<strong>for</strong>mingthis comparative analysis:Hazard assessment is not an indication <strong>of</strong> <strong>the</strong> risk posed by a substance, sinceexposure is not taken into account, but it can be used as an indicator <strong>of</strong>potential to cause effects.The concentration <strong>of</strong> active ingredient in <strong>the</strong> <strong>for</strong>mulated product is also critical.It is quite possible <strong>for</strong> <strong>the</strong> hazard classification <strong>of</strong> alternative <strong>for</strong>mulatedproducts to be less than that <strong>of</strong> dichlorvos containing <strong>for</strong>mulations even when<strong>the</strong> active ingredients are more hazardous (and vice versa) and this is not takeninto account in Table 14.There may be o<strong>the</strong>r active ingredients than those considered in <strong>the</strong>se alternativescenarios if dichlorvos was not available;Restricting <strong>the</strong> suite <strong>of</strong> pesticide modes <strong>of</strong> action available may lead to areduced ability to manage pest resistance.Dichlorvos reassessment – application Page 75 <strong>of</strong> 436
SECTION 6– PROPOSALS TO MANAGE RISKS6.1 Evaluation <strong>of</strong> options to streng<strong>the</strong>n existing controls6.1.1 The analyses in Section 4 identify that certain risks are not well managed by <strong>the</strong>existing controls and are <strong>the</strong>re<strong>for</strong>e non-negligible.6.1.2 Controls additional to those currently in place that might manage <strong>the</strong>se risks aredetailed in <strong>the</strong> following paragraphs. Given <strong>the</strong> specific details <strong>of</strong> each Use Scenario,<strong>the</strong> specifc conditions that are proposed <strong>for</strong> each Use Scenario are detailed in Table7.Off Label use6.1.3 The level <strong>of</strong> risk to human health and <strong>the</strong> environment has not been evaluated <strong>for</strong> <strong>of</strong>flabeluse. The proposals to impose more stringent controls <strong>for</strong> use <strong>of</strong> dichlorvoscontainingsubstances have been developed on <strong>the</strong> basis <strong>of</strong> a risk assessment.Although some <strong>of</strong> <strong>the</strong>se controls may be relevant <strong>for</strong> certain <strong>of</strong>f-label uses, given <strong>the</strong>unassessed nature <strong>of</strong> <strong>of</strong>f-label usage and that ERMA New Zealand does not have <strong>the</strong>in<strong>for</strong>mation to determine acceptable <strong>of</strong>f-label usage, ERMA New Zealand proposesthat <strong>of</strong>f-label usage is prohibited. ERMA New Zealand would welcome additionalin<strong>for</strong>mation to be able to assess use patterns not covered <strong>under</strong> Use Scenarios 1 to32.Use Scenarios 1 – 8: outdoor use as plant protection product6.1.4 Controls and variations to protect <strong>the</strong> environment6.1.4.1 Buffer zones:The analysis in Section 4 shows that impracticably large bufferzones would be needed to protect aquatic invertebrates from spraydrift. APVMA (2008) reached <strong>the</strong> same conclusion and proposedto prohibit <strong>the</strong> use <strong>of</strong> dichlorvos in avocados, <strong>the</strong> only remainingfield use in Australia.The level <strong>of</strong> risk posed to birds through consumption <strong>of</strong> treatedcrops cannot be mitigated by any practical control measures.Timing <strong>of</strong> application <strong>of</strong> dichlorvos-containing substances to avoidtimes bees are <strong>for</strong>aging will reduce <strong>the</strong> risks to bees, but would notreduce <strong>the</strong> risk to o<strong>the</strong>r non-target invertebrates that live within oradjacent to crops.ERMA New Zealand considers that it may be possible to mitigate<strong>the</strong> level <strong>of</strong> risk posed to soil-dwelling invertebrates by reducing <strong>the</strong>application rate, but does not have in<strong>for</strong>mation on <strong>the</strong> lowesteffective rates so cannot determine <strong>the</strong> effect on <strong>the</strong> level <strong>of</strong> risk.ERMA New Zealand notes that direct application <strong>of</strong> dichlorvos towater is prohibited <strong>under</strong> <strong>the</strong> controls specified in <strong>the</strong> existingcontrols suites, and does not impact on <strong>the</strong> risk posed to <strong>the</strong> aquaticenvironment from land-based application <strong>of</strong> dichlorvos. TheUSEPA (2006) have taken <strong>the</strong> same approach, introducing <strong>the</strong>control: Do not apply directly to water, or to areas where surfaceDichlorvos reassessment – application Page 76 <strong>of</strong> 436
water is present or to intertidal areas below <strong>the</strong> mean high watermark.6.1.5 Controls and variations to protect operators and workers6.1.5.1 ERMA New Zealand proposes that Use Scenarios 1 to 8 are prohibitedon <strong>the</strong> basis <strong>of</strong> <strong>the</strong> unmanageable levels <strong>of</strong> risk posed to <strong>the</strong> environment.6.1.5.2 ERMA New Zealand notes that, while it might potentially be possible tomanage <strong>the</strong> non-negligible risks to operators and workers (e.g. throughuse <strong>of</strong> PPE, maximum application rates, use <strong>of</strong> engineeringtechnology),—<strong>the</strong> proposal arising from <strong>the</strong> environmental assessment means thatfur<strong>the</strong>r consideration is not required; andERMA New Zealand does not have <strong>the</strong> in<strong>for</strong>mation available to itto determine whe<strong>the</strong>r effective risk mitigation measures could beimplemented to protect human health.Use Scenarios 9 – 25: Indoor use (industrial)6.1.6 Controls to protect workers – greenhouse, mushroom house, warehouses6.1.6.1 Specified PPE/RPE:A minimum level <strong>of</strong> PPE is required to ensure <strong>the</strong> level <strong>of</strong> risk isnegligible. ERMA New Zealand considers that <strong>the</strong> risks to humanhealth from exposure to dichlorvos are sufficient that <strong>the</strong> level <strong>of</strong>PPE required to ensure negligible risk should be prescribed.6.1.6.2 Remotely activated automated fogging/misting equipment:Use <strong>of</strong> automated equipment can reduce <strong>the</strong> exposure <strong>of</strong> operatorsthrough use, by removing pathway <strong>of</strong> risk to operators.The equipment should be capable <strong>of</strong> being activated remotely toensure that no operators are required to be present in <strong>the</strong> treatmentarea to initiate application.6.1.6.3 Operational controls to restrict number <strong>of</strong> cylinder changes:For use <strong>of</strong> dichlorvos-containing gases, <strong>the</strong> number <strong>of</strong> cylinderchanges is a key factor in determining operator exposure;The assessment carried out has indicated that <strong>the</strong> number <strong>of</strong>cylinder changes should be restricted to 1 cylinder change peroperator per day. ERMA New Zealand notes that a reduction inallowable cylinder changes could result in larger volume cylindersbeing used.Additionally, appropriate levels <strong>of</strong> PPE/RPE are required to ensurethat <strong>the</strong> operator exposure risks are negligible.6.1.6.4 Restriction <strong>of</strong> maximum application rates, mixing quantities and treatedareas:Dichlorvos reassessment – application Page 77 <strong>of</strong> 436
Assessment was carried out with specific use variables, which arerequired to be specified to ensure that <strong>the</strong> risk posed is negligible;For use <strong>of</strong> emulsifiable concentrate <strong>for</strong>mulations, even whenmaximum PPE is worn, exposure to dichlorvos must be restricted.This could be achieved by imposing a maximum application rateand a maximum daily treatment area <strong>for</strong> manual application;For certain Use Scenarios, maximum PPE may be insufficient toprevent exposure risks during mixing and loading. In <strong>the</strong>seinstances, restriction <strong>of</strong> <strong>the</strong> maximum daily mixing/loading quantityis required.6.1.6.5 Restricted entry intervals (REIs)6.1.7 Controls to protect environmentRestrictions on <strong>the</strong> conditions <strong>of</strong> entry into treated buildings willensure that exposure to dichlorvos can be managed;Entry into treated buildings during an REI poses a risk unlessminimum levels <strong>of</strong> PPE are adhered to;Entry into treated buildings during an REI must be <strong>for</strong> specifictasks only, such as initiating ventilation;Entry into treated buildings during an REI <strong>for</strong> certain tasks must berestricted to a specific length <strong>of</strong> time that an operator may spend perday inside treated buildings;Re-entry exposures arising from entry into buildings treated atapplication rates in excess <strong>of</strong> those modelled are likely to be nonnegligible.Maximum application rates should be imposed;6.1.7.1 No quantitative modelling <strong>of</strong> environmental exposure arising from indooruse <strong>of</strong> dichlorvos has been per<strong>for</strong>med. Never<strong>the</strong>less, washing <strong>of</strong> treatedareas, or drainage from greenhouse watering could lead to contamination<strong>of</strong> <strong>the</strong> environment. APVMA (2008) recognise this as an issue applying<strong>the</strong> control ‗Do not allow drainage water from freshly treated areas tocontaminate streams, rivers or waterways‘.6.1.8 It was suggested by Rentokil during <strong>the</strong> preparation <strong>of</strong> this application, that <strong>the</strong>controls on dichlorvos would be streng<strong>the</strong>ned by making it subject to a Controlled<strong>Substance</strong> Licence. A CSL ensures that <strong>the</strong> person handling <strong>the</strong> product has anApproved Handler certificate and has passed a police check. It does not change <strong>the</strong>controls that a user should adopt when handling <strong>the</strong> substance and so does not reduce<strong>the</strong>ir risk, or that <strong>of</strong> bystanders or <strong>the</strong> environment. For <strong>the</strong>se reasons, ERMA NewZealand does not believe that adoption <strong>of</strong> <strong>the</strong> CSL control would reduce <strong>the</strong> risksfrom use <strong>of</strong> dichlorvos and it is not proposed as a possible control option.Use Scenario 26-29: Indoor and outdooe use (domestic)6.1.9 Controls to protect applicators (domestic)6.1.9.1 Restrict use to commercial operators only:Dichlorvos reassessment – application Page 78 <strong>of</strong> 436
6.1.9.2 Specified PPE/RPE:ERMA New Zealand considers that use <strong>of</strong> PPE/RPE is highlyimprobable <strong>for</strong> domestic users. As ERMA New Zealand considersthat use <strong>of</strong> PPE / RPE is a necessity <strong>for</strong> safe use <strong>of</strong> dichlorvos indomestic settings, removal <strong>of</strong> usage by non-commercial applicatorsis required to ensure that by-standers are not exposed.Applicators will be protected if <strong>the</strong>y wear appropriate PPE/RPEduring application;Entry into a treated area would only be allowed if appropriatePPE/RPE was worn during any REI.6.1.9.3 <strong>Application</strong> restrictions:Assessment was carried out with specific use variables, which arerequired to be specified to ensure that <strong>the</strong> risk posed is negligible;If PPE/RPE is not worn during application, applicators may beprotected from exposure by requiring automated application <strong>of</strong>dichlorvos;In addition, remote control <strong>of</strong> application will allow <strong>the</strong> applicatorto leave <strong>the</strong> application area be<strong>for</strong>e any dichlorvos is released;When applied manually, a maximum treatment area and applicationrate will ensure that <strong>the</strong> risks <strong>of</strong> exposure are negligilble.6.1.9.4 Restricted entry intervals:ERMA New Zealand considers that exposure to persons re-entering<strong>the</strong> treated area will be, at worse, similar to Use Scenarios 24 and25, given <strong>the</strong> likely treatment areas and application rates.Restricting access to treated areas will provide protection tobystanders (in particular residents) entering a treated area;The duration <strong>of</strong> <strong>the</strong> required REI will be influenced by <strong>the</strong> level <strong>of</strong>PPE and RPE worn.Use Scenario 30: Outdoor use (public areas)6.1.10 Controls to protect workers6.1.10.1 Specified PPE:The quantitative assessment, carried out assessing a range <strong>of</strong> levels<strong>of</strong> PPE (including RPE), indicates that even with full PPE <strong>the</strong> level<strong>of</strong> risk is non-negligible, and alternative controls are required toensure that <strong>the</strong> level <strong>of</strong> risk to operators is reduced to negligible.6.1.10.2 <strong>Application</strong> methods and maximum daily treatment area:Restricting <strong>the</strong> daily treatment area will provide a means to reduce<strong>the</strong> daily exposure <strong>of</strong> operators;Dichlorvos reassessment – application Page 79 <strong>of</strong> 436
6.1.11 Controls to protect bystandersRestriction <strong>of</strong> application methods to handheld or automatedfogging equipment should restrict <strong>the</strong> level <strong>of</strong> exposure posed tooperators;Use <strong>of</strong> automated remote delivery systems (i.e. no human exposureduring application) should provide a means to reduce operatorexposure to acceptable levels.6.1.11.1 Bystanders will be protected if <strong>the</strong>y are kept a sufficient distance from<strong>the</strong> application area during application and are excluded from <strong>the</strong>application area <strong>for</strong> a suitable period <strong>of</strong> time after application. Methods<strong>of</strong> doing this could include use <strong>of</strong> buffer zones, notification/signage,timing <strong>of</strong> applications to avoid times when <strong>the</strong> public are in <strong>the</strong> area andrestricted entry intervals.6.1.11.2 ERMA New Zealand, however, does not have <strong>the</strong> in<strong>for</strong>mation todetermine any REIs <strong>for</strong> this Use Scenario.6.1.12 Controls to protect <strong>the</strong> environment6.1.12.1 No quantitative modelling <strong>of</strong> environmental exposure arising fromoutdoor, public health use <strong>of</strong> dichlorvos has been per<strong>for</strong>med.Never<strong>the</strong>less, spray drift or run<strong>of</strong>f from treated areas could contaminate<strong>the</strong> environment. Controls applied by APVMA (2008) to manage thisrisk are appropriate in New Zealand:Do not apply <strong>under</strong> meteorological conditions or from sprayequipment that could be expected to cause spray drift onto naturalstreams, rivers or waterways;Avoid excess spraying causing run-<strong>of</strong>f from treated surfaces intountreated areas;Allow treated areas to dry be<strong>for</strong>e washing (or irrigating);Do not apply to exposed areas if rain is expected within 4 hours.Use Scenario 31: biosecurity fruit fly monitoring programme6.1.13 Controls to protect workers6.1.13.1 Specified PPE/RPE:The level <strong>of</strong> exposure through use can likely be reduced throughuse <strong>of</strong> PPE and RPE.6.1.13.2 Limit number <strong>of</strong> traps to be serviced per day:The level <strong>of</strong> exposure is proportional to <strong>the</strong> number <strong>of</strong> strips that anoperator handles each day.The number <strong>of</strong> traps/strips handled by operators per day should berestricted to ensure <strong>the</strong> level <strong>of</strong> PPE / RPE proposed is adequate toprevent inhalation exposure.Dichlorvos reassessment – application Page 80 <strong>of</strong> 436
6.1.13.3 Guidance to provide in<strong>for</strong>mation <strong>for</strong> operators regarding <strong>the</strong> transport <strong>of</strong>DDVP strips and sachets should be developed by <strong>the</strong> registrant to ensurethat operators are aware <strong>of</strong> <strong>the</strong> risks posed by open <strong>of</strong> damaged sachetscontaining DDVP strips.6.1.13.4 By specifying identification requirements to be placed on trapscontaining dichlorvos-containing strips that indicate <strong>the</strong> potential <strong>for</strong> aninhalation risk should ensure that <strong>the</strong> level <strong>of</strong> adverse effects tobystanders is negligible.6.2 Evaluation <strong>of</strong> options to reduce risk by restricting use6.2.1 The risks posed by a substance can be removed by restricting <strong>the</strong> use <strong>of</strong> <strong>the</strong>substance, ei<strong>the</strong>r by revoking approvals or by imposing controls that restrict use toparticular applications. Given that no risk assessment has been carried out <strong>for</strong> <strong>of</strong>flabelusage, in order to ensure that use <strong>of</strong> dichlorvos-containing substances are usedin a manageable fashion <strong>the</strong>n use must be restricted to those detailed on <strong>the</strong> productlabels, taking into consideration any implications <strong>of</strong> this reassessment.6.2.2 The discussion in Section 2 indicates that in some sectors <strong>the</strong> risks can be controlledby streng<strong>the</strong>ning <strong>the</strong> controls. In sectors where this is not <strong>the</strong> case, revocation <strong>of</strong> <strong>the</strong>approval is proposed.6.3 Effect <strong>of</strong> proposed additional controls on <strong>the</strong> level <strong>of</strong> risk6.3.1 The Use Scenarios have been reproduced in Table 15 to assist in <strong>under</strong>standing <strong>the</strong>proposed additional controls.6.3.2 The effect on <strong>the</strong> final level <strong>of</strong> risk by <strong>the</strong> addition <strong>of</strong> controls to reduce exposure isdetailed in Table 16.Table 15Summary <strong>of</strong> Use Scenarios.UseOutdooragricultural useIndoor agriculturaluseIndoor nonagriculturaluseIndoor domesticuseOutdoor domesticuseOutdoor nonagriculturaluseManufacture <strong>for</strong>exportUse Scenario1, 2 (boom application: strawberries)3, 4 (boom application: vegetables, cereals, berries)5, 6 (air-blast application: fruit - tamarillo, persimmon, berries)7, 8 (hand-held sprayer: passionfruit)9, 10, 11, 12 (automatic fogging: glasshouse crops, mushroom houses)13, 14 (automatic fogging: glasshouse flowers)15, 16 (manual spraying: glasshouse flowers)17, 18, 20, 21 (automatic fogging: enclosed space (industrial))19, 22, 23 (manual fogging: enclosed space (industrial))24, 25 (manual spraying: enclosed space (industrial))26, 27 (manual application: enclosed space (domestic))28, 29 (manual application: enclosed space (domestic))30 (manual fogging: public outdoor use)31 (MAF-BNZ fruit fly monitoring)32 (<strong>for</strong> exportation)Dichlorvos reassessment – application Page 81 <strong>of</strong> 436
Table 16Effect <strong>of</strong> additional controls on <strong>the</strong> level <strong>of</strong> risk.Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Off-label useEnvironmentHuman HealthOutdoor use as plant protection productNon-negligible(potentially)Proposed Additional ContolUse <strong>of</strong> substances is restricted to those uses specified on <strong>the</strong>product label, in accordance with <strong>the</strong> outcomes <strong>of</strong> thisreassessment.Modified Level <strong>of</strong>RiskNegligible1 - 4 Aquatic environment(invertebrates)Non-negligible (> LOC)No practical options available to reduce risk to aquaticinvertebrates.Non-negligible(High).Terrestrial environment(vertebrates)Terrestrial environment(invertebrates)Operator exposure(mixing, loading,application)Non-negligible (> LOC) No practical options available to reduce risks to birds. Non-negligible(High).Non-negligible (> LOC)Non-negligible (> AOEL)Restriction <strong>of</strong> <strong>the</strong> timing <strong>of</strong> application to avoidexposure <strong>of</strong> <strong>for</strong>aging bees.No practical options available to reduce risk to nontargetterrestrial invertebrates in or close to <strong>the</strong>application area.No practical options available to reduce risks to operatorsduring mixing, loading or application.Non-negligible(High).Non-negligible.Operator exposure(restricted entry)Non-negligible (> AOEL)No practical options available to reduce risks tooperators during restricted entry into treated crops,except where restricted entry is into cereals <strong>for</strong> <strong>the</strong>purpose <strong>of</strong> scouting;Introduce a REI <strong>of</strong> 7 days, where restricted entry intocereals <strong>for</strong> scouting is prohibited without PPE/RPE;Non-negligible.(vegetables, berries)Negligible(scouting in cereals)Introduce minimum PPE/RPE requirements <strong>for</strong>restricted entry into cereals <strong>for</strong> scouting during REI:Dichlorvos reassessment – application Page 82 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolScouting in cereals:PPE:- hood/visor,- overalls over long-sleeved shirt and long-leggedtrousers;- boots;- gloves.RPE:- half-face respirator, with minimum specification<strong>of</strong> A1P2.Modified Level <strong>of</strong>Risk5 - 6 Aquatic environment(invertebrates)Terrestrial environment(vertebrates)Non-negligible (> LOC)No practical options available to reduce risk to aquaticinvertebrates.Non-negligible(High).Non-negligible (> LOC) No practical options available to reduce risks to birds. Non-negligible(High).Terrestrial environment(invertebrates)Non-negligible (> LOC)Restriction <strong>of</strong> <strong>the</strong> timing <strong>of</strong> application to avoidexposure <strong>of</strong> <strong>for</strong>aging bees.Non-negligible(High).No practical available to reduce risk to non-targetterrestrial invertebrates in or close to <strong>the</strong> applicationarea.Terrestrial environment(soil-dwellingorganisms)Non-negligible (> LOC)No practical options available to reduce risks to soil-dwellingorganisms.Non-negligible.Operator exposure(mixing, loading,Non-negligible (> AOEL)No practical options available to reduce risks to operatorsduring mixing, loading or application..Non-negligible.Dichlorvos reassessment – application Page 83 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)application)Operator exposure(restricted entry)Non-negligible (> AOEL)Proposed Additional ContolNo practical options available to reduce risks to operatorsduring restricted entry.Modified Level <strong>of</strong>RiskNon-negligible.7 - 8 Aquatic environment(invertebrates)Non-negligible (> LOC)No practical options available to reduce risk to aquaticinvertebrates.Non-negligible(High).Terrestrial environment(vertebrates)Terrestrial environment(invertebrates)Operator exposure(mixing, loading,application)Operator exposure(restricted entry)Non-negligible (> LOC) No practical options available to reduce risks to birds. Non-negligible(High).Non-negligible (> LOC)Non-negligible (> AOEL)Non-negligible (> AOEL)Restriction <strong>of</strong> <strong>the</strong> timing <strong>of</strong> application to avoidexposure <strong>of</strong> <strong>for</strong>aging bees.No practical options available to reduce risk to nontargetterrestrial invertebrates (in or close to <strong>the</strong>application area).No practical options available to reduce risks to operatorsduring mixing, loading or application.No practical options available to reduce risks to operatorsduring restricted entry.Non-negligible(High).Non-negligible.Non-negligible.Indoor use (industrial)9 - 10 Operator exposure(mixing, loading)Non-negligible(> AOEL)Automatic, remote application to ensure no operatorexposure during application;Restrict number <strong>of</strong> cylinder changes to 1 per operatorper day;Negligible.Prescribe minimum levels <strong>of</strong> PPE/RPE <strong>for</strong> connection /disconnection <strong>of</strong> cylinders:PPE:Dichlorvos reassessment – application Page 84 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Operator exposure(restricted entry)Non-negligible(> AOEL)Proposed Additional Contol- glovesRPE:- full-face respirator, with minimum specification<strong>of</strong> A1P2.<strong>Application</strong> rates should be restricted to 0.05 g a.i. / m 3 ,in order <strong>for</strong> an REI to be set.Introduce REIs:- entry into treated glasshouse areas <strong>for</strong> anypurpose is prohibited <strong>for</strong> 4 hours after completion<strong>of</strong> application; and- restricted entry into treated glasshouse areas ispermitted after at least 4 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- restricted entry into treated glasshouse areas ispermitted after at least 4 hours has elapsed sincecommencement <strong>of</strong> ventilation <strong>for</strong> tending tasks;- restricted entry into treated mushroom houses ispermitted after at least 48 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> any task;- restricted entry into treated glasshouse areas ormushroom houses is permitted after at least 72hours has elapsed since commencement <strong>of</strong>ventilation <strong>for</strong> harvesting or o<strong>the</strong>r tasks thatinvolve contact with treated crops.Introduce PPE/RPE requirements <strong>for</strong> entry into treatedModified Level <strong>of</strong>RiskNegligible.Dichlorvos reassessment – application Page 85 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contolglasshouse areas <strong>for</strong> ventilation tasks:PPE:- hood/visor,- overalls over long-sleeved shirt and long-leggedtrousers;- boots;- gloves.RPE:- full-face with minimum specification <strong>of</strong> A1P2, orair-hose respirator.Introduce PPE/RPE requirements <strong>for</strong> post-ventilationentry into treated glasshouse areas, or any tasks intreated mushroom houses:PPE:- hat and goggles,- overalls over long-sleeved shirt and long-leggedtrousers;- boots;- gloves.Introduce a maximum exposure time persons enteringtreated areas:- <strong>for</strong> ventilation tasks, < 30 minute / day;- <strong>for</strong> tending tasks, < 2 hours / day, until at least 72Modified Level <strong>of</strong>RiskDichlorvos reassessment – application Page 86 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contolhours has elapsed since completion <strong>of</strong>application;- <strong>for</strong> any tasks in mushroom houses, < 2 hours /day, until at least 72 hours has elapsed sincecompletion <strong>of</strong> application.Modified Level <strong>of</strong>Risk11 – 12 Operator exposure(mixing, loading)Non-negligible(> AOEL)Automatic, remote application to ensure no operatorexposure during application;Maximum quantity to be mixed per operator per day,equivalent to 56 g dichlorvos;Non-negligibleIntroduce PPE/RPE requirements <strong>for</strong> use by operators:Mixing/loadingPPE:- glovesRPE:- half-face respirator with minimum specification<strong>of</strong> A1P2.Operator exposure(restricted entry)Non-negligible(> AOEL)<strong>Application</strong> rates should be restricted to 0.05 g a.i. / m 3 ,in order <strong>for</strong> an REI to be set.NegligibleIntroduce REIs:- restricted entry into treated glasshouse areas ispermitted after at least 4 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- restricted entry into treated glasshouse areas ispermitted after at least 4 hours has elapsed sinceDichlorvos reassessment – application Page 87 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contolcommencement <strong>of</strong> ventilation <strong>for</strong> tending tasks;- restricted entry into treated mushroom houses ispermitted after at least 48 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> any task;- restricted entry into treated glasshouse areas ormushroom houses is permitted after at least 72hours has elapsed since commencement <strong>of</strong>ventilation <strong>for</strong> harvesting or o<strong>the</strong>r tasks thatinvolve contact with treated crops.Introduce PPE/RPE requirements <strong>for</strong> entry into treatedglasshouse areas <strong>for</strong> ventilation tasks:PPE:- hood/visor,- overalls over long-sleeved shirt and long-leggedtrousers;- boots;- gloves.RPE:- full-face with minimum specification <strong>of</strong> A1P2, orair-hose respirator.Introduce PPE/RPE requirements <strong>for</strong> post-ventilationentry into treated glasshouse areas, or any tasks intreated mushroom houses:PPE:Modified Level <strong>of</strong>RiskDichlorvos reassessment – application Page 88 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contol- hat and goggles,- overalls over long-sleeved shirt and long-leggedtrousers;- boots;- gloves.Modified Level <strong>of</strong>RiskIntroduce a maximum exposure time persons enteringtreated areas:- <strong>for</strong> ventilation tasks, < 30 minute / day;- <strong>for</strong> tending / harvesting tasks, < 2 hours / day,until at least 72 hours has elapsed sincecompletion <strong>of</strong> application.;- <strong>for</strong> any tasks in mushroom houses, < 2 hours /day, until at least 72 hours has elapsed sincecompletion <strong>of</strong> application.13 - 14 Operator exposure(mixing, loading)Negligible(> AOEL)Automatic, remote application to ensure no operatorexposure during application;Negligible.Maximum quantity to be mixed per operator per day,equivalent to 56 g dichlorvos;Introduce PPE/RPE requirements <strong>for</strong> use by operators:Mixing/loadingPPE:- glovesRPE:Dichlorvos reassessment – application Page 89 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Operator exposure(restricted entry)Non-negligible(> AOEL)Proposed Additional Contol- half-face respirator with minimum specification<strong>of</strong> A1P2.<strong>Application</strong> rate should be restricted to 0.05 g a.i. / m 3 ,in order <strong>for</strong> an REI to be set.Introduce REIs:- entry into treated glasshouse areas <strong>for</strong> anypurpose is prohibited <strong>for</strong> 4 hours after completion<strong>of</strong> application; and- restricted entry into treated glasshouse areas ispermitted after 4 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- restricted entry into treated glasshouse areas ispermitted after at least 4 hours has elapsed sincecommencement <strong>of</strong> ventilation <strong>for</strong> tending tasks;- restricted entry into treated glasshouse areas ispermitted after at least 72 hours has elapsed sincecommencement <strong>of</strong> ventilation <strong>for</strong> harvesting oro<strong>the</strong>r tasks that involve contact with treatedcrops.Introduce PPE/RPE requirements <strong>for</strong> entry into treatedglasshouse areas <strong>for</strong> ventilation tasks:PPE:- hood/visor,- overalls over long-sleeved shirt and long-leggedtrousers;Modified Level <strong>of</strong>RiskNegligible.Dichlorvos reassessment – application Page 90 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contol- boots;- gloves.RPE:- full-face with minimum specification <strong>of</strong> A1P2, orair-hose respirator.Introduce PPE/RPE requirements <strong>for</strong> post-ventilationentry into treated glasshouse areas:PPE:- hat and goggles,- overalls over long-sleeved shirt and long-leggedtrousers;- boots;- gloves.Introduce a maximum exposure time persons enteringtreated areas:- <strong>for</strong> ventilation tasks, < 30 minute / day;- <strong>for</strong> tending / harvesting tasks, < 1 hours / dayuntil at least 72 hours has elapsed sincecompletion <strong>of</strong> application.Modified Level <strong>of</strong>Risk15, 16 Operator exposure(mixing, loading,application)Non-negligible (> AOEL)No practical options available to reduce risks to operatorsduring mixing, loading or application.Non-negligible.Operator exposure Non-negligible (> AOEL) No REI can be set <strong>for</strong> <strong>the</strong>se Use Scenarios, based on an Non-negligible.Dichlorvos reassessment – application Page 91 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contol(restricted entry) application rate <strong>of</strong> 0.7 g a.i./m 3 .17, 18 Operator exposure(mixing, loading)Non-negligible(> AOEL)Automatic, remote application to ensure no operatorexposure during application;Restrict number <strong>of</strong> cylinder changes to 1 per operatorper day.Prescribe minimum levels <strong>of</strong> PPE/RPE <strong>for</strong> connection /disconnection <strong>of</strong> cylinders:PPE:- glovesRPE:- full-face respirator, with minimum specification<strong>of</strong> A1P2.Modified Level <strong>of</strong>RiskNegligibleOperator exposure(restricted entry)Non-negligible(> AOEL)<strong>Application</strong> rates should be restricted to 0.15 g a.i. / m 3 ,in order <strong>for</strong> an REI to be set.Negligible.Introduce REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; and- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- unrestricted entry into buildings treated at ratesup to 0.05 g a.i. / m 3 <strong>for</strong> o<strong>the</strong>r tasks is permittedafter at least 72 hours after commencement <strong>of</strong>ventilation;Dichlorvos reassessment – application Page 92 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contol- unrestricted entry into buildings treated at ratesabove 0.05 g a.i. / m 3 , up to 0.15 g a.i. / m 3 <strong>for</strong>o<strong>the</strong>r tasks is permitted after at least 120 hoursafter commencement <strong>of</strong> ventilation.Introduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:RPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;Introduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> ventilation tasks, < 30 minute/ day.Modified Level <strong>of</strong>Risk19 Operator exposure(mixing, loading,application)Non-negligible(> AOEL)Introduce maximum treated area <strong>of</strong> 3750 m 3 peroperator per day;Restrict number <strong>of</strong> cylinder changes to 1 per operatorper day.Negligible.Prescribe minimum levels <strong>of</strong> PPE/RPE:Connection / disconnection <strong>of</strong> cylindersPPE:- glovesRPE:- full-face respirator, with minimum specification<strong>of</strong> A1P2.Dichlorvos reassessment – application Page 93 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contol<strong>Application</strong>PPE:- chemical resistant overalls;- boots;- glovesRPE:- air-hose respirator.Modified Level <strong>of</strong>RiskOperator exposure(restricted entry)Non-negligible(>AOEL)<strong>Application</strong> rates should be restricted to 0.15 g a.i. / m 3 ,in order <strong>for</strong> an REI to be set.Negligible.Introduce a REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; and- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- unrestricted entry <strong>for</strong> o<strong>the</strong>r tasks in buildingstreated at 0.05 g a.i. / m 3 is permitted 72 hoursafter commencement <strong>of</strong> ventilation; and- unrestricted entry <strong>for</strong> o<strong>the</strong>r tasks in buildingstreated at 0.15 g a.i. / m 3 is permitted 120 hoursafter commencement <strong>of</strong> ventilation.Introduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:Dichlorvos reassessment – application Page 94 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolRPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;Modified Level <strong>of</strong>RiskIntroduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> ventilation tasks, < 30 minute/ day.20 - 21 Operator exposure(mixing, loading)Non-negligible(> AOEL)Automatic, remote application to ensure no operatorexposure during application;Negligible.Maximum quantity to be mixed per operator per day,equivalent to 56 g dichlorvos;Introduce PPE requirements:PPE:- GlovesRPE:- Half-face respirator with minimum specification<strong>of</strong> A1P2.Operator exposure(restricted entry)Non-negligible(> AOEL)<strong>Application</strong> rates should be restricted to 0.15 g a.i. / m 3 ,in order <strong>for</strong> an REI to be set.Negligible.Introduce a REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; and- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksDichlorvos reassessment – application Page 95 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contolonly; and- unrestricted entry into buildings treated at 0.05 ga.i. / m 3 is permitted after at least 72 hours aftercommencement <strong>of</strong> ventilation; and- unrestricted entry into buildings treated at 0.15 ga.i. / m 3 is permitted after at least 120 hours aftercommencement <strong>of</strong> ventilation.Introduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:RPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;Modified Level <strong>of</strong>RiskIntroduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> ventilation tasks, < 30 minute/ day.22 - 23 Operator exposure(mixing, loading,application)Non-negligible(> AOEL)Introduce a maximum application rates 0.15 g a.i. / m 3 ;Introduce a maximum quantity to be mixed per operatorper day, equivalent to 56 g dichlorvos;Negligible.Introduce a maximum treated volume <strong>of</strong> 375 m 3 peroperator per day;Introduce PPE / RPE requirements:Mixing/loadingPPE:- GlovesDichlorvos reassessment – application Page 96 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolRPE:- Half-face respirator with minimum specification<strong>of</strong> A1P2.<strong>Application</strong>PPE:- Chemical resistant overalls;- Boots;- GlovesRPE:- Half-face respirator with minimum specification<strong>of</strong> A1P2.Modified Level <strong>of</strong>RiskOperator exposure(restricted entry)Non-negligible(> AOEL)Introduce a REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; andNegligible.- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- unrestricted entry into buildings treated at 50 mg/ m 3 is prohibited until at least 72 hours aftercommencement <strong>of</strong> ventilation; and- unrestricted entry into buildings treated at 150mg / m 3 is prohibited until at least 120 hours aftercommencement <strong>of</strong> ventilation.Dichlorvos reassessment – application Page 97 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolIntroduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:RPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;Modified Level <strong>of</strong>RiskIntroduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> ventilation tasks, < 30 minute/ day.24, 25 Operator exposure(mixing, loading,application)Non-negligible(> AOEL)Introduce a maximum application rate <strong>of</strong> 0.3 g a.i. / m 2 ;Introduce a maximum quantity to be mixed per operatorper day, equivalent to 56 g dichlorvos;Negligible.Introduce a maximum treated volume <strong>of</strong> 150 m 2 peroperator per day and equivalent mixing/loadingquantity;Introduce PPE/RPE requirements:Mixing, loading, application:PPE:- Chemical resistant overalls;- Boots;- GlovesRPE:- Air-hose RPE.Dichlorvos reassessment – application Page 98 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Operator exposure(restricted entry)Indoor use (domestic use)Non-negligible(> AOEL)Proposed Additional ContolIntroduce a REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; and- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and;- unrestricted entry into treated buildings <strong>for</strong> o<strong>the</strong>rtasks is prohibited until at least 120 hours aftercommencement <strong>of</strong> ventilation;Introduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:RPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;REI:- half-face respirator with minimum specification<strong>of</strong> A1P2.Introduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> ventilation, < 30 minute/ day.Modified Level <strong>of</strong>RiskNegligible.26 - 27 Operator exposure(mixing, loading,application)Non-negligible(> AOEL)Restrict use to commercial use only, and in industriallocations only – remove exemption <strong>for</strong> approvedhandler requirements;Negligible.Dichlorvos reassessment – application Page 99 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional Contol[PPE: unlikely to be used in a domestic setting]Introduce a maximum application rate <strong>of</strong> 0.3 g a.i. / m 2 ;Introduce a maximum treated volume <strong>of</strong> 150 m 2 peroperator per day and equivalent mixing/loadingquantity;Introduce PPE requirements:Mixing, loading, application:PPE:- Chemical resistant overalls;- Boots;- GlovesRPE:- Air-hose RPE.Modified Level <strong>of</strong>RiskOperator exposure(restricted entry)Non-negligible(> AOEL)Introduce a REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; andNegligible- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> ventilation tasksonly; and- unrestricted entry into treated buildings <strong>for</strong> o<strong>the</strong>rtasks is prohibited until at least 120 hours aftercommencement <strong>of</strong> ventilation.Dichlorvos reassessment – application Page 100 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolIntroduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:RPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;REI:- Half-face respirator with minimum specification<strong>of</strong> A1P2.Modified Level <strong>of</strong>RiskIntroduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> ventilation, < 30 minute/ day.Bystander exposureNon-negligible(> AOEL)ERMA New Zealand is unable to determine an REI <strong>for</strong>domestic usage.Non-negligibleNo practical options available to reduce risks to childrenentering treated areas.Outdoor use (domestic use)28 - 29 Operator exposure(mixing, loading,application)Non-negligible(> AOEL)Restrict use to commercial use only, and in industriallocations only – remove exemption <strong>for</strong> approvedhandler requirements;[PPE: unlikely to be used in a domestic setting]Negligible.Introduce a maximum application rate <strong>of</strong> 0.3 g a.i. / m 2 ;Introduce a maximum treated volume <strong>of</strong> 150 m 2 peroperator per day and equivalent mixing/loadingquantity;Dichlorvos reassessment – application Page 101 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolIntroduce PPE requirements:Mixing, loading, application:PPE:- Chemical resistant overalls;- Boots;- GlovesRPE:- Air-hose RPE.Modified Level <strong>of</strong>RiskOperator exposure(restricted entry)Non-negligible(> AOEL)Introduce a REIs:- entry into treated areas is prohibited <strong>for</strong> 10 hoursafter completion <strong>of</strong> application; andNegligible- restricted entry into treated glasshouse areas ispermitted after at least 10 hours has elapsed sincecompletion <strong>of</strong> application <strong>for</strong> tasks that do notinvolve contact with treated areas;- unrestricted entry into treated buildings <strong>for</strong> o<strong>the</strong>rtasks is prohibited until at least 120 hours aftercompletion <strong>of</strong> application;Introduce minimum PPE/RPE requirements <strong>for</strong> entryinto treated buildings <strong>for</strong> ventilation tasks:RPE:- half-face respirator with minimum specification<strong>of</strong> A1P2;Dichlorvos reassessment – application Page 102 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolREI:- Half-face respirator with minimum specification<strong>of</strong> A1P2.Modified Level <strong>of</strong>RiskIntroduce a maximum exposure time <strong>for</strong> entry intotreated area:- <strong>for</strong> tasks within 120 hours <strong>of</strong> completion <strong>of</strong>application, < 30 minute/ day.Bystander exposureNon-negligible(> AOEL)ERMA New Zealand is unable to determine an REI <strong>for</strong>domestic usage.Non-negligibleNo practical risk reduction options available.Outdoor use (public spaces)30 Aquatic environment Non-negligible (> LOC) Restrict to automated or handheld fogging equipment.Operator exposure(mixing, loading,Avoid run-<strong>of</strong>f contamination <strong>of</strong> aquatic systems:- Do not apply <strong>under</strong> meteorological conditions orfrom spray equipment that could be expected tocause spray drift onto natural streams, rivers orwaterways;- Avoid excess spraying causing run-<strong>of</strong>f fromtreated surfaces into untreated areas;- Allow treated areas to dry be<strong>for</strong>e washing (orirrigating);- Do not apply to exposed areas if rain is expectedwithin 4 hours.NegligibleNon-negligible Restrict to automated or handheld fogging equipment; NegligibleDichlorvos reassessment – application Page 103 <strong>of</strong> 436
Use Scenario Receptor Level <strong>of</strong> Risk (with existingcontrols in place)Proposed Additional ContolModified Level <strong>of</strong>Riskapplication) (> AOEL) Maximum treatment area <strong>of</strong> 150 m 2 per operator perday and equivalent mixing/loading quantity.Operator and bystanderexposure(restricted entry)Non-negligible(> AOEL)ERMA New Zealand is unable to determine an REI <strong>for</strong> publicspace usage.Non-negligibleBiosecurity fruit fly monitoring programme31 Operator exposure(application/retrieval/checking)Non-negligibleIntroduce minimum PPE/RPE requirements <strong>for</strong> tasksinvolving dichlorvos-containing strips:PPENegligible- gloves;- handled strips with <strong>for</strong>ceps..RPE- half-face respirator, with minimum specification<strong>of</strong> A1P2.Restrict <strong>the</strong> number <strong>of</strong> strips handled / traps serviced byoperators per day to 90.Guidance (e.g. SOP) to be provided to operators byregistrants regarding carriage <strong>of</strong> DDVP strips andsachets.Bystander exposure Non-negligible Introduce additional labelling requirements on <strong>the</strong> trapsidentifying a potential inhalation risk.NegligibleDichlorvos reassessment – application Page 104 <strong>of</strong> 436
SECTION 7 – OVERALL EVALUATION7.1 Evaluation <strong>of</strong> options to reduce risk by restricting use7.1.1 In <strong>the</strong> absence <strong>of</strong> exposure in<strong>for</strong>mation, ERMA New Zealand has used quantitativeexposure assessment models to determine <strong>the</strong> levels <strong>of</strong> risk to human health and <strong>the</strong>environment. This exposure modelling has produced indicative levels <strong>of</strong> risk that, inmany cases, are high.7.1.2 On <strong>the</strong> basis <strong>of</strong> this in<strong>for</strong>mation, ERMA New Zealand‘s interim evaluation is that<strong>the</strong>re are significant (non-negligible) risks associated with <strong>the</strong> use <strong>of</strong> dichlorvos inNew Zealand which outweigh <strong>the</strong> benefits and need to be managed. Most notably:risks posed to <strong>the</strong> aquatic environment;risks to birds;risks to non-target invertebrates;risks to operators;risks to bystanders.7.1.3 ERMA New Zealand notes that use <strong>of</strong> substances would be based on alternativeactive ingredients if <strong>the</strong> use <strong>of</strong> dichlorvos was restricted or prohibited:Potential alternatives have been identified <strong>for</strong> some agricultural uses <strong>of</strong>dichlorvos and <strong>the</strong> hazards <strong>of</strong> <strong>the</strong>se are shown in Table 14; many have a lowerhazard pr<strong>of</strong>ile.For some crop/pest combinations no alternatives have been identified.Never<strong>the</strong>less, all <strong>the</strong> crops on which dichlorvos is used in New Zealand aregrown overseas in countries that do not use dichlorvos in plant protectionproducts.7.1.4 ERMA New Zealand also notes that <strong>the</strong>re are particular benefits associated with <strong>the</strong>use <strong>of</strong> dichlorvos, notably:dichlorvos has a different mode <strong>of</strong> action to o<strong>the</strong>r products that may be used ifits use is restricted or prevented. Maintaining a suite <strong>of</strong> products with differentmodes <strong>of</strong> action is an important means <strong>of</strong> reducing <strong>the</strong> likelihood <strong>of</strong>development <strong>of</strong> pest resistance:dichlorvos possesses a unique combination <strong>of</strong> physical and chemical propertiesthat can provide rapid knock-down <strong>of</strong> pests, with short withholding periods,and can be used close to harvest, where o<strong>the</strong>r products might be precluded:dichlorvos used in <strong>the</strong> biosecurity fruit fly monitoring programme, which hassignificant economic significance, and <strong>for</strong> which no alternatives have beenidentified.7.1.5 ERMA New Zealand notes that <strong>the</strong> comparison <strong>of</strong> risks or benefits, <strong>for</strong> example arisk <strong>of</strong> chronic human toxic effects compared to a risk <strong>of</strong> aquatic toxic effects, and<strong>the</strong> comparison <strong>of</strong> risks and benefits, <strong>for</strong> example an environmental or human healthrisk to a societal or economic benefit, requires value judgement. This is taken intoaccount in making recommendations (Section 6.1) and <strong>the</strong> Authority will take thisinto account in reaching an overall assessment <strong>of</strong> <strong>the</strong> risks and benefits.7.1.6 This evaluation takes into account that ERMA New Zealand‘s assessment is basedon <strong>the</strong> in<strong>for</strong>mation that is available to it. Additional in<strong>for</strong>mation is welcomed. ERMANew Zealand invites submitters to provide additional in<strong>for</strong>mation that <strong>the</strong>y mightDichlorvos reassessment – application Page 105 <strong>of</strong> 436
have, and notes <strong>the</strong> following as areas where additional in<strong>for</strong>mation may beparticularly useful:<strong>the</strong> level <strong>of</strong> benefit <strong>of</strong>fered by dichlorvos substances, especially regardingsocial effects from <strong>the</strong> use <strong>of</strong> dichlorvos (e.g. effect on local employmentopportunities and direct/indirect local community impact arising fromdichlorvos use);<strong>the</strong> level <strong>of</strong> ecomonic benefit provided to <strong>the</strong> public health sector bydichlorvos;<strong>the</strong> financial implications <strong>of</strong> overseas restrictions on crops treated withdichlorvos;identification <strong>of</strong> <strong>the</strong> use and availability <strong>of</strong> alternative substances, withparticular regard to dichlorvos use in non-agricultural enclosed space use;identification <strong>of</strong> use patterns that have not been included in <strong>the</strong> assessment;provision <strong>of</strong> data to determine when unrestricted entry into treated glasshousesor mushroom houses can occur;identification <strong>of</strong> minimum effective application rates, which may be used torefine <strong>the</strong> exposure assessment;feasibility <strong>of</strong> proposed risk management measures, and <strong>the</strong> implications <strong>of</strong> <strong>the</strong>modified control regime (such as financial implications <strong>of</strong> installing orupgrading application equipment).7.1.7 ERMA New Zealand notes that <strong>the</strong> Authority must consider <strong>the</strong> costs and benefits <strong>of</strong>varied or additional controls, in accordance with clause 35 <strong>of</strong> <strong>the</strong> Methodology 7 . If<strong>the</strong> recommendations from this assessment are adopted <strong>the</strong>re may be additional costsrequired to users arising from a need to upgrade existing or install new equipment inorder to continue to use dichlorvos <strong>for</strong> certain uses. The net level <strong>of</strong> benefit may bereduced as a result. ERMA New Zealand invites submitters to provide in<strong>for</strong>mationrelating to <strong>the</strong> cost implications <strong>of</strong> adopting <strong>the</strong> proposed recommendations.7.1.8 Although some in<strong>for</strong>mation on <strong>the</strong>se matters has been provided to ERMA NewZealand in <strong>the</strong> course <strong>of</strong> preparing this application, <strong>the</strong> statutory public submissionsperiod allows a fur<strong>the</strong>r opportunity <strong>for</strong> in<strong>for</strong>mation to be provided which could resultin <strong>the</strong> Authority establishing a higher level <strong>of</strong> risks, costs or benefits.7.1.9 Clauses 29 and 30 <strong>of</strong> <strong>the</strong> Methodology provides that where <strong>the</strong>re is scientific andtechnical uncertainty, <strong>the</strong> Authority must consider <strong>the</strong> materiality <strong>of</strong> <strong>the</strong> uncertaintyand if it cannot be resolved to its satisfaction, <strong>the</strong> Authority must take into account<strong>the</strong> need <strong>for</strong> caution in managing <strong>the</strong> adverse effects <strong>of</strong> <strong>the</strong> substance.7.1.10 Given <strong>the</strong> in<strong>for</strong>mation currently be<strong>for</strong>e it and taking account <strong>of</strong> <strong>the</strong> need <strong>for</strong> caution,ERMA New Zealand makes <strong>the</strong> preliminary recommendations set out in Section 7.4.7<strong>Hazardous</strong> <strong>Substance</strong>s and New Organisms (Methodology) Order 1998 (SR 1998/217).Dichlorvos reassessment – application Page 106 <strong>of</strong> 436
7.2 Overall Evaluation7.2.1 A summary <strong>of</strong> <strong>the</strong> risks, benefits and overall proposals <strong>for</strong> <strong>the</strong> Use Scenarios <strong>for</strong>dichlorvos-containing substances are details in Table 17, Table 18 and Table 19.7.2.2 Outcome Scenario (c) means that, while <strong>the</strong> unavailability <strong>of</strong> dichlorvos means that<strong>the</strong> level <strong>of</strong> adverse effects is regarded as non-existent, <strong>the</strong> level <strong>of</strong> benefit that mayarise from its availability can also not be realised. This is classed as an absence <strong>of</strong>benefit, ra<strong>the</strong>r than an adverse effect.Table 17.Summary <strong>of</strong> risks <strong>for</strong> Use Scenarios and Outcome Scenarios <strong>for</strong>dichlorvos-containing substances.UseScenarioOutcomeScenario (a)(continued use)1 - 8 Environmental:Non-negligibleHuman Health:Non-negligible9 – 29, 31 Environmental:NegligibleHuman Health:Non-negligible30 Environmental:Non-negligibleHuman Health:Non-negligible32 Environmental:NegligibleHuman Health:NegligibleOutcomeScenario (b)(restricteduse/additionalcontrols)Environmental:Non-negligibleHuman Health:Non-negligibleEnvironmental:Human Health:Environmental:Human Health:NegligibleNegligibleNegligibleNon-negligibleEnvironmental:Human Health:NegligibleNegligibleOutcomeScenario (c)(withdrawn –reliance onalternatives)Environmental:Human Health:Environmental:Human Health:Environmental:Human Health:Environmental:Human Health:NoneNoneNoneNoneNoneNoneNoneNoneDichlorvos reassessment – application Page 107 <strong>of</strong> 436
Table 18Summary <strong>of</strong> benefits associated with scenarios.Receptor(Use Scenario)Human health(All UseScenarios)Environment(All UseScenarios)Relationship <strong>of</strong>Māori to <strong>the</strong>environment(All UseScenarios)OutcomeScenario (a)(continued use)OutcomeScenario (b)(restricteduse/additionalcontrols)OutcomeScenario (c)(withdrawn –reliance onalternatives)Negligible Negligible NoneNegligible Negligible NoneNegligible Negligible NoneSociety andCommunities:Agricultural use(Use Scenarios1 to 16)Public health use(Use Scenarios17 to 30)Biosecurity use(Use Scenario31)MarketEconomy:Agricultural use(Use Scenarios1 to 16)Public health use(Use Scenarios17 to 29)(Use Scenario30)Biosecurity use(Use Scenario31)Negligible Negligible NoneNon-negligible(Low)Non-negligible(Low)NoneNegligible Negligible NoneNon-negligible(Low)Non-negligible(v. Low)Non-negligible(Low)Non-negligible(v. Low)NoneNoneNegligible Negligible NoneNon-negligible(Low to medium)Non-negligible(Low to medium)NoneDichlorvos reassessment – application Page 108 <strong>of</strong> 436
Table 19.Overall evaluation – summary <strong>of</strong> combined non-negligible effects.UseScenariosAssessment <strong>of</strong>EffectOutcomeScenario (a)(continued use)OutcomeScenario (b)(restricted use/additionalcontrols)OutcomeScenario (c)(discontinued use)Outdoor agricultural usage (HSNO Approvals HSR000211, HSR000213)1 - 8Adverse (-ve) Non-negligible Non-negligible NonePositive (+ve) Non-negligible Non-negligible NoneOverall -ve ≥ +ve -ve ≥ +ve Enclosed space, agricultural usage (HSNO Approvals HSR000211, HSR000212,HSR000213)9 - 16Adverse (-ve) Non-negligible Negligible NonePositive (+ve) Non-negligible Non-negligible NoneOverall -ve ≥ +ve -ve < +veEnclosed space, industrial usage (HSNO Approvals HSR000211, HSR000212,HSR000213)17 - 25Adverse (-ve) Non-negligible Negligible NonePositive (+ve) Non-negligible Non-negligible NoneOverall -ve ≥ +ve -ve < +veEnclosed space, domestic usage (HSNO Approvals HSR000207, HSR000209)26 - 29Adverse (-ve) Non-negligible Negligible NonePositive (+ve) Non-negligible Non-negligible NoneOverall -ve ≥ +ve -ve < +veOutdoor public space usage (HSNO Approvals HSR000211, HSR000213)30Adverse (-ve) Non-negligible Non-negligible NonePositive (+ve) Non-negligible Non-negligible NoneOverall -ve ≥ +ve -ve ≥ +ve Biosecurity use (HSNO Approval HSR000126)31Adverse (-ve) Non-negligible Negligible NonePositive (+ve) Non-negligible Non-negligible NoneOverall -ve ≥ +ve -ve < +veManufacture <strong>for</strong> export (HSNO Approval HSR001757)32Dichlorvos reassessment – application Page 109 <strong>of</strong> 436-ve > +veAdverse (-ve) Negligible Negligible NonePositive (+ve) Negligible Negligible NoneOverall-ve ≤ +ve
UseScenariosAssessment <strong>of</strong>EffectOutcomeScenario (a)OutcomeScenario (b)OutcomeScenario (c)(continued use)(restricted use/additionalcontrols)(discontinued use)Notes:Proposed Outcome Scenario7.3 Proposed additions and modifications to controls <strong>under</strong>section 77A7.3.1 The Outcome Scenarios have been evaluated <strong>for</strong> individual Use Scenarios. A singleapproval may contain numerous Use Scenarios. Additional controls have beenproposed <strong>for</strong> particular Use Scenarios and are <strong>the</strong>re<strong>for</strong>e appropriate <strong>for</strong> <strong>the</strong> associatedapprovals. The Use Scenarios are applicable to specific approvals <strong>for</strong> dichlorvoscontainingsubstances.7.3.2 Applying <strong>the</strong> Outcome Scenarios to <strong>the</strong> relevant approvals <strong>for</strong> dichlorvos anddichlorvos-containing substances results in <strong>the</strong> following proposals <strong>for</strong> variations to<strong>the</strong> conditions <strong>for</strong> each approval.7.3.3 Given <strong>the</strong> diverse use patterns <strong>for</strong> individual approvals, Outcome Scenario (b)includes withdrawal <strong>of</strong> specific Use Scenarios. The approval conditions, overall,would be restricted, but individual Use Scenarios may be discontinued. In order <strong>for</strong>an approval to be discontinued, all <strong>of</strong> <strong>the</strong> individual Use Scenarios would need to bediscontinued. Table 20 summarises <strong>the</strong> Outcome Scenarios <strong>for</strong> each substanceapproval containing dichlorvos.Table 20.Outcome Scenarios <strong>for</strong> approvals. “Restricted use” includeswithdrawal <strong>of</strong> specific Use Scenarios.Approvalnumber<strong>Substance</strong>DescriptionOutcomeScenario (a)OutcomeScenario (b)OutcomeScenario (c)(continued use)(restricted use /additionalcontrols)(discontinueduse)HSR002838Dichlorvos[CAS #62-73-7]HSR000212Aerosolcontaining 50 g/kgdichlorvosHSR000211Emulsifiableconcentratecontaining 1000g/litre dichlorvosHSR000213Emulsifiableconcentratecontaining 1140g/litre dichlorvosDichlorvos reassessment – application Page 110 <strong>of</strong> 436
Approvalnumber<strong>Substance</strong>DescriptionOutcomeScenario (a)OutcomeScenario (b)OutcomeScenario (c)(continued use)(restricted use /additionalcontrols)(discontinueduse)HSR000207HSR000209HSR000126Flammableaerosol containing3.1 g/litredichlorvos and 8.7g/litre propoxurReady to useliquid containing4.4 g/litredichlorvos and 9.6g/litre propoxurDDVP InsecticideStripHSR001757 J72.03 Notes:Proposed Outcome Scenario7.3.4 The diverse usage <strong>of</strong> dichlorvos means that multiple Use Scenarios may apply toeach approval, and individual Use Scenarios may apply to multiple approvals.7.3.5 ERMA New Zealand proposes that <strong>the</strong> use <strong>of</strong> dichlorvos is restricted as follows:Use <strong>of</strong> dichlorvos that is not in accordance with label instructions is prohibited.Dichlorvos, when applied as a spray, fog or aerosol, may be applied in indoorcommercial or industrial locations only.Maximum application rates, maximum treatment areas or volumes, maximumdaily limits <strong>for</strong> operator dichlorvos handling (including mixing/loading,connection <strong>of</strong> cylinders, application <strong>of</strong> dichlorvos strips) are specified.PPE/RPE requirements are specified <strong>for</strong> various stages <strong>of</strong> <strong>the</strong> substance‘slifecycle.Entry into treated areas must be in accordance with <strong>the</strong> restricted entryintervals (REIs) and conditions specified.7.3.6 The specific proposals <strong>for</strong> each approval are detailed in Table 21. The appropriateUse Scenarios in Table 16 should be referred to, in order to provide details <strong>of</strong> <strong>the</strong>variations that apply to <strong>the</strong> dichlorvos approvals. In <strong>the</strong> interests <strong>of</strong> clarity, <strong>the</strong>specific details have not been reproduced here.Table 21.Summary <strong>of</strong> <strong>the</strong> proposed variations to approvals <strong>for</strong> dichlorvos anddichlorvos-containing substances.<strong>Substance</strong> detailsHSR002838Dichlorvos[CAS #62-73-7]Proposed variationsNo variations to existing conditions proposed.Dichlorvos reassessment – application Page 111 <strong>of</strong> 436
<strong>Substance</strong> detailsHSR000126DDVPInsecticide StripUse Scenario31HSR000207Flammableaerosolcontaining 3.1g/litre dichlorvosand 8.7 g/litrepropoxurUse Scenarios26-27HSR000209Ready to useliquid containing4.4 g/litredichlorvos and9.6 g/litrepropoxurUse Scenarios28-29HSR000211Emulsifiableconcentratecontaining 1000g/litre dichlorvosUse Scenarios1-8,11-16,20-25,30Proposed variations1. Use that is not in accordance with <strong>the</strong> label instructionsis prohibited;2. Introduce PPE requirements <strong>for</strong> operators;3. Restrict <strong>the</strong> number <strong>of</strong> strips handled / traps serviced byoperators per day;4. Labelling requirements to identify <strong>the</strong> inhalation risk;5. Provision <strong>of</strong> guidance material <strong>for</strong> transportation and use<strong>of</strong> DDVP Strips.1. Use that is not in accordance with <strong>the</strong> label instructionsis prohibited;2. Restrict use to industrial sites and by commercialapplicators only – approved handler exemption removed;3. Introduce PPE/RPE requirements;4. <strong>Application</strong> methods to be restricted to remote,automatic delivery systems;5. Introduce maximum application rates and treatmentareas;6. Introduce a restricted entry intervals;7. Introduce a maximum exposure time <strong>for</strong> entry intotreated area.1. Use that is not in accordance with <strong>the</strong> label instructionsis prohibited;2. Restrict use to industrial sites and by commercialapplicators only – approved handler exemption removed;3. Introduce PPE/RPE requirements;4. <strong>Application</strong> methods to be restricted to remote,automatic delivery systems;5. Introduce maximum application rates and treatmentareas;6. Introduce a restricted entry intervals;7. Introduce a maximum exposure time <strong>for</strong> entry intotreated area.1. Use that is not in accordance with <strong>the</strong> label instructionsis prohibited;2. Outdoor agricultural or public area use is prohibited;3. <strong>Application</strong> methods to be restricted to remote,automatic delivery systems, or limited manual handspraying;4. Apply a maximum quantity that an individual maymix/load per day;5. Introduce maximum application rates;6. Introduce PPE/RPE requirements;7. Introduce a restricted entry intervals;Dichlorvos reassessment – application Page 112 <strong>of</strong> 436
<strong>Substance</strong> detailsHSR000212Aerosolcontaining 50g/kg dichlorvosUse Scenarios9-10, 17-19HSR000213Emulsifiableconcentratecontaining 1140g/litre dichlorvosUse Scenarios1-8,11-16,20-25,30HSR001757J72.03Use Scenarios32Proposed variations8. Introduce a maximum exposure time <strong>for</strong> entry intotreated area.1. Use that is not in accordance with <strong>the</strong> label instructionsis prohibited;2. Introduce PPE/RPE requirements <strong>for</strong> connection /disconnection <strong>of</strong> cylinders, and entry into treated areas;3. Restrict number <strong>of</strong> cylinder changes per operator perday;4. Introduce maximum application rates;5. Introduce a maximum daily treatment volume peroperator per day <strong>for</strong> manual application;6. Introduce a restricted entry intervals;7. Introduce a maximum exposure times <strong>for</strong> entry intotreated area <strong>for</strong> different tasks.1. Use that is not in accordance with <strong>the</strong> label instructionsis prohibited;2. Outdoor agricultural or public area use is prohibited;3. <strong>Application</strong> methods to be restricted to remote,automatic delivery systems, or limited manual handspraying;4. Apply a maximum quantity that an individual maymix/load per day;5. Introduce PPE/RPE requirements;6. Introduce maximum application rates;7. Introduce a restricted entry intervals;8. Introduce a maximum exposure time <strong>for</strong> entry intotreated area.No variations to existing conditions proposed.7.3.7 ERMA New Zealand has considered risk management options <strong>for</strong> use <strong>of</strong> dichlorvos<strong>for</strong>mulations and concluded that certain risks can be adequately managed byenhanced controls, such as:risks to <strong>the</strong> health <strong>of</strong> operators can be managed by prescription <strong>of</strong> PPE/RPE;anduse, application and restricted entry intervals restrictions.7.3.8 O<strong>the</strong>r risks cannot be adequately managed by realistic controls:buffer zones, greater than can be determined by <strong>the</strong> modelling <strong>under</strong>taken (i.e.in excess <strong>of</strong> 300 m) would be required around water bodies and <strong>the</strong>se are notconsidered to be practical;Dichlorvos reassessment – application Page 113 <strong>of</strong> 436
Table 22.<strong>the</strong>re are no practicable risk reduction measures to protect birds or non-targetinvertebrates;exposure risks to children returning to treated locations.7.3.9 ERMA New Zealand has assessed exposures based on specific usage in<strong>for</strong>mationavailable to it during its evaluation. The details <strong>of</strong> recommendations based on thisusage in<strong>for</strong>mation (such as application rates and methods, or PPE/RPE requirements)will reflect <strong>the</strong> criteria used to carry out <strong>the</strong> assessment.7.3.10 ERMA New Zealand considers that, if <strong>the</strong> proposed additional controls andrestrictions are accepted, a phase-in period <strong>of</strong> 12 months should also be adopted togive affected parties time to accommodate <strong>the</strong> revised conditions.7.3.11 ERMA New Zealand proposes that <strong>the</strong> classifications <strong>for</strong> dichlorvos and dichlorvoscontainingsubstances should be modified as detailed in Table 22.Summary <strong>of</strong> proposed hazard classifications <strong>for</strong> dichlorvos and dichlorvos-containingsubstances.Hazard ClassDichlorvosReady touse liquidcontaining4.4 g/ldichlorvos& 9.6 g/lpropoxurEmulsifiableconcentratecontaining1000 g/ldichlorvosAerosolcontaining50 g/kgdichlorvosEmulsifiableconcentratecontaining1140 g/ldichlorvosFlammableaerosolcontaining3.1 g/ldichlorvosand 8.7 g/lpropoxurDichlorvos reassessment – application Page 114 <strong>of</strong> 436DDVPinsecticidestripApproval # HSR002838 HSR000209 HSR000211 HSR000212 HSR000213 HSR000207 HSR000126 HSR001757Flammability No No No No 2.1.2A No No NoAcute toxicityN/A,N/A,6.1B 6.1D 6.1C6.1C(oral)aerosolaerosol6.1D 6.1CAcute toxicity(dermal)6.1B 6.1E 6.1B 6.1D 6.1B No 6.1E 6.1CAcute toxicity(inhalation)6.1B No 6.1B 6.1C 6.1C No 6.1C 6.1BSkinirritancy/corrosion6.3B 6.3B 6.3B No 6.3B 6.3B 6.3B 6.3BEyeirritancy/corrosion6.4A 8.3A 6.4A No 6.4A 6.4A 6.4A 6.4AContactsensitisation6.5B 6.5B 6.5B 6.5B 6.5B 6.5B 6.5B 6.5BMutagenicity 6.6B No 6.6B 6.6B 6.6B ND 6.6B 6.6BCarcinogenicity 6.7B 6.7B 6.7B 6.7B 6.7B 6.7B 6.7B 6.7BReproductive/developmentalNo No 6.8A No ND ND ND NotoxicityTarget organsystemic toxicity6.9A 6.9B 6.9A 6.9B 6.9A 6.9B 6.9A 6.9AAquaticecotoxicity9.1A 9.1A 9.1A 9.1A 9.1A 9.1A 9.1A 9.1ASoil ecotoxicity 9.2D No 9.2D No 9.2D ND ND NDTerrestrialvertebrate9.3A 9.3B 9.3A 9.3B 9.3A 9.3B 9.3B 9.3BecotoxicityTerrestrialinvertebrateecotoxicity9.4A 9.4B 9.4A 9.4A 9.4A 9.4B 9.4A 9.4AJ72.03
7.3.12 In preparing this application, ERMA New Zealand has not conducted a specificMāori consultation but <strong>the</strong> impression gained from hui with iwi/Māori resourcemanagers is that unless substances provide clear benefits to outweigh potential risk,<strong>the</strong>y generally oppose <strong>the</strong> ongoing use <strong>of</strong> hazardous substances. In <strong>the</strong> absence <strong>of</strong>fur<strong>the</strong>r in<strong>for</strong>mation regarding benefits, it is expected that submissions from Māoriwould seek <strong>the</strong> revocation <strong>of</strong> <strong>the</strong> approvals <strong>for</strong> dichlorvos and its <strong>for</strong>mulations.7.3.13 Clauses 29 and 30 <strong>of</strong> <strong>the</strong> Methodology 8 provides that where <strong>the</strong>re is scientific andtechnical uncertainty, <strong>the</strong> Authority must consider <strong>the</strong> materiality <strong>of</strong> <strong>the</strong> uncertaintyand if it cannot be resolved to its satisfaction, <strong>the</strong> Authority must take into account<strong>the</strong> need <strong>for</strong> caution in managing <strong>the</strong> adverse effects <strong>of</strong> <strong>the</strong> substance.7.3.14 Given <strong>the</strong> in<strong>for</strong>mation currently be<strong>for</strong>e it and taking account <strong>of</strong> <strong>the</strong> need <strong>for</strong> caution,ERMA New Zealand makes <strong>the</strong> preliminary recommendations set out in Section 7.4.8<strong>Hazardous</strong> <strong>Substance</strong>s and New Organisms (Methodology) Order 1998 (SR 1998/217).Dichlorvos reassessment – application Page 115 <strong>of</strong> 436
7.4 Preliminary Recommendations7.4.1 ERMA New proposes <strong>the</strong> revised classifications (Table 22) are adopted <strong>for</strong>dichlorvos and dichlorvos-containing substances.7.4.2 Discontinue Use (Outcome Scenario (c)) is proposed <strong>for</strong> outdoor agricultural andpublic area uses.7.4.3 Continue Use (Outcome Scenario (a)) is proposed <strong>for</strong> dichlorvos (approval numberHSR002838).7.4.4 Continue Use (Outcome Scenario (a)) is proposed <strong>for</strong> J72.03 (approval numberHSR001757).7.4.5 Restrict Use / Additional Controls (Outcome Scenario (b)) is proposed <strong>for</strong> <strong>the</strong>following dichlorvos-containing substances:DDVP Insecticide Strip (approval number HSR000126);Flammable aerosol containing 3.1 g/litre dichlorvos and 8.7 g/litre propoxur(approval number HSR000207);Ready to use liquid containing 4.4 g/litre dichlorvos and 9.6 g/litre propoxur(approval number HSR000209);Emulsifiable concentrate containing 1000 g/litre dichlorvos (approval numberHSR000211);Aerosol containing 50 g/kg dichlorvos (approval number HSR000212);Emulsifiable concentrate containing 1140 g/litre dichlorvos (approval numberHSR000213).7.4.6 ERMA New Zealand proposes that <strong>the</strong>se recommendations are phased-in over a 12month period.Signed_______________________________________Chief Executive, ERMA New Zealand.Dated ____________23 November 2010____________Dichlorvos reassessment – application Page 116 <strong>of</strong> 436
Table A.2:Methods <strong>of</strong> analysisAnalytical methods <strong>for</strong> <strong>the</strong> active ingredient (ai)Technical ai(principle <strong>of</strong> method)Impurities intechnical ai(principle <strong>of</strong> method)Dichlorvos as technical product can be determined according toaccepted analytical methods. A generally accepted method is<strong>the</strong> product analysis by reaction with excess <strong>of</strong> iodine that isestimated by tritation. This method is described in CIPACHandbook 1980,1A,1214. Ano<strong>the</strong>r method is gaschromatography (GLC), which is described in CIPACProceedings, 1981,3,173. Procedures are described <strong>for</strong> <strong>the</strong>analysis <strong>of</strong> dichlorvos technical by infrared spectroscopy and byan iodometric method: IR or GC/FID (method AW1/5)GC/FID (Denka method no.31) not validatedAnalytical methods were described <strong>for</strong> <strong>the</strong> determination o<strong>for</strong>ganic and additional by-products. The following organic byproductswere considered: Methylchloride, Deschlor-C177(CGA 320114), CGA236317 and CGA110990. Fur<strong>the</strong>rmethods <strong>for</strong> <strong>the</strong> determination <strong>of</strong> water and free acids werepresented. Methylchloride, CGA 320114, CGA 236317, CGA110990.GC/FID (method AK1/2)LOQ = 0.1% methylchlorideLOQ=10 ppm CGA 110990For deschlor-C177 (CGA320114) and (CGA236317) novalidation could be pre<strong>for</strong>med because no reference substanceswere available. The structures <strong>of</strong> <strong>the</strong>se compounds and <strong>the</strong>irchromatographic behaviour are similar to dichlorvos. Thedetermination in samples was done using dichlorvos as externalstandard.WaterMethod: Karl FisherLOQ=>50, 100 ppmFree acidsFree acids were determined by <strong>the</strong> alcalimetric method. Apotentiometric titration <strong>of</strong> free acids was per<strong>for</strong>med in awater/acetone mixture. The calculation was a sulphuric acid.Method AK 1/2 is not fully validated.TMP, ChloralAnalytical methods <strong>for</strong> residuesCalorimetric method (Denka analytical method no 107) notacceptableCVDC Chloral trichlorfonLC(reverse-phase)/UV (Denka analytical method no 109) notvalidatedWater (small quantities)Coloumetric (Denka analytical method no 110) LOQ= up to 1ppm, not validatedChloral, TMP,DMP,DMMP,TMPO,CVDPGLC/TCD (denka analytical method no 111) not validatedEU,2005EU,2005Soil (principle <strong>of</strong> Dichlorvos EU,2005Dichlorvos reassessment – application Page 118 <strong>of</strong> 436
method and LOQ)Water (principle <strong>of</strong>method and LOQ)Matrix: soil and ryegrassGC/AFID (cross reference KIIA 4.2.2/01)Not validatedTrichlorfonMatrix: soil and turfgrassGC/EC/NPD (cross reference:KII4.2.2/02)Soil LOQ=0.02 ppm (EC), 0.09 ppm (NPD)Turfgrass LOQ=0.04 (EC), 0.2 ppm (NPD)If used <strong>for</strong> monitoring purpose needs an independent laboratoryvalidation that should be per<strong>for</strong>med to GLP standard.DichlorvosMatrix: loch waterGC/ECD (cross reference KIIA 4.2.3/01)LOQ= 0.001 mg/LNot fully validatedEU,2005Matrix: waterHPLC/UV-Vis (cross reference KIIA 4.2.3/02)Not fully validatedMatrix: waterSPE (solid phase extraction)GC/SIM/MS (cross reference KIIA4.2.3/03)LOQ= 1 ng/gNot acceptableMatrix:distilled waterGC/MS (cross reference KIIA4.2.3/04)LOQ= 30 ig/LNot acceptableMatrix: waterSPME GC/NPD-SPME GC/MS-EPA 507 GLC/NPD (crossreference KIIA 4.2.3/05)LOQ= 2.50 ig/L EPA 507-GLC/NPDLOQ= 1.50 ig/L SPME GC/NPDLOQ=0.08 ig/L SPME GC/MSNot validatedAir (principle <strong>of</strong>method and LOQ)DichlorvosGC/FPD or GC/AFID (cross reference KIIA 4.2.4/01) NotvalidatedEU,2005GC/FPD (cross reference KIIA 4.2.4/02) Not acceptableDichlorvos reassessment – application Page 119 <strong>of</strong> 436
GC/FPD (cross reference KIIA 4.2.4/03)LOQ=0.0019 mg/m 3GC/FPD (cross reference KIIA 4.2.4/04) LOQ=0.10 ig/sampleNot acceptableGC/FPD (cross reference KIIA 4.2.4/05)Potassium nitrate method/drechsel methodNot fully validatedBody fluids andtissues (principle <strong>of</strong>method and LOQ)DichlorvosMatrix:lean tissue fluidsGLC/FPD (cross reference KIIA4.2.5/01)LOQ= 0.10 ppmNot fully validatedMatrix: serum urine (body fluid)HPLC/UV Diode-array detector array (cross reference KIIA4.2.5/02)LOQ= 6.8 mg/L (230 nm)Not fully validatedEU,2005Dichlorvos reassessment – application Page 120 <strong>of</strong> 436
Appendix B: Environmental Fate <strong>of</strong> dichlorvosTable B.1:Terrestrial fate and behaviour <strong>of</strong> dichlorvosDegradation in soilSummary In<strong>for</strong>mationSoil photolysis Sandy loam soil, pH7 DT 50 15.5 days (same soil in dark, DT 50 , 16.5days)Aerobic, laboratorystudiesDT 50 lab (sandy loam, pH 5.7, slightly humic sand pH6.1),
Degradates, 2,2-dichloroacetic acid (26.6%) and 2,2-dichloroethanol(4.4%).From concrete and glass surfaces: DT 50
Bioconcentration factor Gnathopogon caerulescens (willow shiner), BCF≤1.2 APVMA, 2008Table B.3:Fate and behaviour in air <strong>of</strong> dichlorvosDirect photolysisin airSummary In<strong>for</strong>mationReferenceNot expected from UV spectrum.APVMA, 2008DT 50
Appendix C: Environmental Exposure modellingAs ERMA New Zealand is unaware <strong>of</strong> locally monitored exposure concentrations, its riskassessment is based on modelling estimated environmental concentrations.Concentrations in surface waterERMA New Zealand has used <strong>the</strong> Generic Estimated Environmental Concentration Model v2(GENEEC2) surface water exposure model (USEPA 2001) to estimate <strong>the</strong> expectedenvironmental concentration (EEC) <strong>of</strong> dichlorvos in surface water which may potentially ariseas a result <strong>of</strong> spray drift and surface run<strong>of</strong>f, following wide dispersive use.The parameters used in <strong>the</strong> GENEEC2 modelling are listed in Table C.1.Table C.1:Input parameters <strong>for</strong> GENEEC2 analysis<strong>Application</strong> rate<strong>Application</strong> frequency<strong>Application</strong> intervalSee Table C2DichlorvosK d 0.41 USEPA, 1997Aerobic soil DT 50 1 day EU, 2005Pesticide wetted in?Methods <strong>of</strong> application‗No spray‘ zonenoSee Table C2noWater solubility 15 000 mg/l APVMA 2008Aerobic aquatic DT 50 1 day EU, 2005Aqueous photolysis DT 50 10.2 days USEPA, 2006ReferenceThe results <strong>of</strong> <strong>the</strong> modelling are summarised in Table C2 and <strong>the</strong> model output is shown inTable C3.Dichlorvos reassessment – application Page 124 <strong>of</strong> 436
Table C.2:Scenarios used in exposure modelling and aquatic estimated environmental concentrations <strong>for</strong> dichlorvosCrop Method rate scenario applications Estimated environmental concentration( µg/l)Equipment details Max gramai/ha/applicationNumberper yearInterval(days)peak 4 dayavg21 dayavg60 dayavgstrawberries boom Low,fine –mediumdropletVegetables,cereals, berriesFruit(tam./pers./berry)boomairblastHigh,fine –mediumdropletFinemediumdropletpassionfruit knapsack Finemediumdroplet800 1 1 - 9.7 6.0 1.5 0.5 0.32 2 7 9.8 6.1 1.5 0.5 0.4800 3 1 - 10.2 6.4 1.6 0.5 0.44 2 7 10.3 6.5 1.6 0.6 0.42052 5 1 - 27.1 17.2 4.2 1.5 1.06 2 7 27.5 17.5 4.3 1.5 1.01026 7 1 - 13.0 8.2 2.0 0.7 0.58 2 7 13.2 8.3 2.0 0.7 0.590 dayavgDichlorvos reassessment – application Page 125 <strong>of</strong> 436
Table C.3:Output from GENEEC2 exposure modellingScenario 1: Strawberry- 1 applicationRUN No. 1 FOR dichlorvos ON strawberri * INPUT VALUES *---------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)---------------------------------------------------------------------------------------------------------.712( .712) 1 1 .415000.0 GRLOFI( 2.9) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)---------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)---------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001-------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC-------------------------------------------------------------------------------------------------9.69 6.04 1.47 .52 .34Scenario 2: Strawberry – 2 applicationsRUN No. 2 FOR dichlorvos ON strawberri * INPUT VALUES *---------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)---------------------------------------------------------------------------------------------------------.712( .718) 2 7 .415000.0 GRLOFI( 2.9) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)-------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)--------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001---------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC---------------------------------------------------------------------------------------------------9.79 6.10 1.49 .52 .35Dichlorvos reassessment – application Page 126 <strong>of</strong> 436
Scenario 3: Vegetables – 1 applicationRUN No. 3 FOR dichlorvos ON vegetables * INPUT VALUES *--------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)--------------------------------------------------------------------------------------------------------.712( .712) 1 1 .415000.0 GRHIFI( 6.6) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)--------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)--------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001---------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC---------------------------------------------------------------------------------------------------10.16 6.41 1.56 .55 .37Scenario 4: Vegetables – 2 applicationsRUN No. 4 FOR dichlorvos ON vegetables * INPUT VALUES *----------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)----------------------------------------------------------------------------------------------------------.712( .718) 2 7 .415000.0 GRHIFI( 6.6) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)-------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)-------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001--------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC--------------------------------------------------------------------------------------------------10.29 6.50 1.59 .56 .37Scenario 5: Fruit- 1 applicationRUN No. 5 FOR dichlorvos ON fruit * INPUT VALUES *Dichlorvos reassessment – application Page 127 <strong>of</strong> 436
-----------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)----------------------------------------------------------------------------------------------------------1.827( 1.827) 1 1 .415000.0 ORCHAR( 9.7) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)--------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)--------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001--------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC-------------------------------------------------------------------------------------------------27.07 17.23 4.21 1.47 .98Scenario 6: Fruit- 2 applicationsRUN No. 6 FOR dichlorvos ON fruit * INPUT VALUES *--------------------------------------------------------------------------------------------------------RATE (lbAC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)-------------------------------------------------------------------------------------------------------1.827( 1.841) 2 7 .415000.0 ORCHAR( 9.7) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)---------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)--------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001---------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC---------------------------------------------------------------------------------------------------27.47 17.52 4.28 1.50 1.00Scenario 7: Passionfruit- 1 applicationRUN No. 7 FOR dichlorvos ON passionfru * INPUT VALUES *-------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)-------------------------------------------------------------------------------------------------------.913( .913) 1 1 .415000.0 GRHIFI( 6.6) .0 .0Dichlorvos reassessment – application Page 128 <strong>of</strong> 436
FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)--------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)--------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001------------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC------------------------------------------------------------------------------------------------------13.03 8.22 2.01 .70 .47Scenario 8: Passionfruit- 2 applicationsRUN No. 8 FOR dichlorvos ON passionfru * INPUT VALUES *----------------------------------------------------------------------------------------------------------RATE (lb/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORPONE(MULT) INTERVAL Kd (PPM ) (%DRIFT) ZONE(FT) (IN)----------------------------------------------------------------------------------------------------------.913( .921) 2 7 .415000.0 GRHIFI( 6.6) .0 .0FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)-----------------------------------------------------------------------------------------------------------------------METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED(FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND)----------------------------------------------------------------------------------------------------------------------1.00 2 N/A 10.20- 1264.80 1.00 1.00GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001------------------------------------------------------------------------------------------------------PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAYGEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC-----------------------------------------------------------------------------------------------------13.20 8.34 2.04 .71 .48To examine how buffer zones would reduce <strong>the</strong> dichlorvos concentration in aquatic receivingwaters, ERMA New Zealand used <strong>the</strong> AgDrift model. The model was set to estimate <strong>the</strong>dichlorvos concentration in a 30 cm deep pond. The model indicated that at 304 m from <strong>the</strong>application area, <strong>the</strong> limit <strong>of</strong> <strong>the</strong> model, drift from a low boom, fine droplet size would beapproximately 0.1% <strong>of</strong> <strong>the</strong> field application rate.Concentrations in groundwaterThe concentration in groundwater has been estimated using <strong>the</strong> USEPA SCIGROW model.For one application <strong>the</strong> concentration ranges from 0.00069 to 0.00178 µg/L. For twoapplications <strong>the</strong> concentration ranges from 0.00138 to 0.00357 µg/L.Dichlorvos reassessment – application Page 129 <strong>of</strong> 436
Terrestrial exposureBirds – food exposure terrestrial and aquatic food chains.The avian toxicity assessment was per<strong>for</strong>med according to ―Risk Assessment to Birds andMammals‖ (EFSA 2008). Dichlorvos is considered not to be bioaccumulative, so this was nottaken into account in <strong>the</strong> assessment. The bird exposure assessment is based on <strong>the</strong>concentration <strong>of</strong> dichlorvos in <strong>the</strong> diet and <strong>the</strong> quantity <strong>of</strong> food consumed. The ‗daily dietarydose‘ (DDD) is defined by <strong>the</strong> food intake rate <strong>of</strong> <strong>the</strong> species <strong>of</strong> concern (i.e. <strong>the</strong> indicatorspecies), <strong>the</strong> body weight <strong>of</strong> <strong>the</strong> species <strong>of</strong> concern, <strong>the</strong> concentration <strong>of</strong> a substance in/onfresh diet and <strong>the</strong> fraction <strong>of</strong> diet obtained in <strong>the</strong> treated area. The estimated food intake ratesare based on <strong>the</strong> daily energy expenditure <strong>of</strong> <strong>the</strong> species <strong>of</strong> concern, <strong>the</strong> energy in <strong>the</strong> food,<strong>the</strong> ‗energy‘ assimilation efficiency <strong>of</strong> <strong>the</strong> species <strong>of</strong> concern, and <strong>the</strong> moisture content <strong>of</strong> <strong>the</strong>food. The above in<strong>for</strong>mation is combined into a single value <strong>for</strong> specific species-cropcombinations and termed a ‗shortcut value‘. The daily dietary dose <strong>for</strong> a single applicationcan be calculated by multiplying <strong>the</strong> shortcut value with <strong>the</strong> application rate. When asubstance is applied more than once a multiple application factor <strong>for</strong> 90 th percentile residuedata is taken into account (MAF 90 ).DDD single application = application rate (kg/ha) x shortcut valueDDD multiple applications = DDD single application x MAF 90The toxicity-exposure ratio (TER) can be calculated by dividing <strong>the</strong> LD 50 value by <strong>the</strong> dailydietary dose (Appendix F).TER = LD 50 / DDDThe first step <strong>of</strong> <strong>the</strong> risk assessment is <strong>the</strong> ‗screening step‘ that uses an indicator species andworst case assumptions regarding exposure. If a substance and its use do not pass <strong>the</strong>screening step, <strong>the</strong>n <strong>the</strong> next step is <strong>the</strong> first-tier risk assessment. This uses more realisticexposure estimates (i.e. crop growth stages) along with a ‗generic focal species‘.ERMA New Zealand calculated <strong>the</strong> DDD values <strong>for</strong> <strong>the</strong> indicator species <strong>for</strong> <strong>the</strong> differentcrops and <strong>the</strong> results <strong>for</strong> dichlorvos are shown <strong>for</strong> acute toxicity in Tables C4 (screening step)and C5 (Tier 1). No assessment was made <strong>for</strong> chronic toxicity due to <strong>the</strong> short half-life <strong>of</strong>dichlorvos.Table C4:Daily dietary dose used in <strong>the</strong> screening step <strong>for</strong> <strong>the</strong> assessment <strong>of</strong> acute toxicity<strong>of</strong> dichlorvosScenario Crop 1 Species 2Indicator1,3 Strawberries,vegetables,cereals,berries2,4 Strawberries,vegetables,cereals,berriesSmall omnivorousbirdSmall omnivorousbird5 Fruit (trees) Smallinsectivorous birdShort-cutvalue 3(90 th percentileRUD)<strong>Application</strong>rate (kg/ha) MAF 904Dichlorvos reassessment – application Page 130 <strong>of</strong> 436DDD 5158.8 0.8 1 127.04158.8 0.8 1.4 177.8646.8 2.052 1 96.036 Fruit (trees) Small 46.8 2.052 1.4 134.45
insectivorous bird7 Passionfruit Smallinsectivorous bird8 Passionfruit Smallinsectivorous bird46.8 1.026 1 48.0246.8 1.026 1.4 67.22Additional details provided in EFSA (2008):1Crop type Table I.1 (Annex 1) and Appendix 102Species type Table I.1 (Annex 1) and Appendix 103Residue Unit Dose (90 th percentile) Table I.1 (Annex 1)4 Multiple application factor (90 th percentile) Table 1.1 and Appendix 155 DDD = daily dietary doseTable C5:Daily dietary dose <strong>for</strong> first tier assessment <strong>of</strong> acute toxicity dichlorvosScenario Crop 1 IndicatorSpecies 2Short-cutvalue 3(90 th percentileRUD)<strong>Application</strong>rate (kg/ha)MAF 904DDD 51 Strawberry(BBCH 10-19)1 Strawberry(BBCH 20-39)1 Strawberry(BBCH ≥40)1 Strawberry(BBCH 10-19)1 Strawberry(BBCH ≥20)2 Strawberry(BBCH 10-19)2 Strawberry(BBCH 20-39)2 Strawberry(BBCH ≥40)2 Strawberry(BBCH 10-19)2 Strawberry(BBCH ≥20)3 Cereals(BBCH 10-19)3 Cereals (BBCH20-29)SmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallomnivorousbirdSmallomnivorous24 0.8 1 19.222.9 0.8 1 18.3210.7 0.8 1 8.5626.8 0.8 1 21.4425.2 0.8 1 20.1624 0.8 1.4 26.8822.9 0.8 1.4 25.6510.7 0.8 1.4 11.9826.8 0.8 1.4 30.0225.2 0.8 1.4 28.2224 0.8 1 19.222.9 0.8 1 18.32Dichlorvos reassessment – application Page 131 <strong>of</strong> 436
3 Cereals3 Cereals(BBCH 30-39)(BBCH ≥40)4 Cereals(BBCH 10-19)4 Cereals (BBCH20-29)4 Cereals4 Cereals(BBCH 30-39)(BBCH ≥40)3 Leafyvegetables(BBCH 10-49)3 Leafyvegetables(BBCH ≥50)3 Leafy + fruitingvegetables andpulses(BBCH 10-19)3 Leafy + fruitingvegetables andpulses(BBCH 20-49)3 Leafy + fruitingvegetables andpulses(BBCH ≥50)3 Leafyvegetables andpulses(BBCH 10-19)3 Leafy + fruitingvegetables andpulses(BBCH 10-19)3 Leafy + fruitingvegetables andpulses(BBCH ≥20)4 Leafyvegetables(BBCH 10-49)birdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdmediumherbivorous/granivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallgranivorousbird12.7 0.8 1 10.168.6 0.8 1 6.8824 0.8 1.4 26.8822.9 0.8 1.4 18.3212.7 0.8 1.4 14.228.6 0.8 1.4 9.6327.3 0.8 1 21.848.2 0.8 1 6.5624 0.8 1 19.222.9 0.8 1 18.328.6 0.8 1 6.8890.6 0.8 1 72.4826.8 0.8 1 21.4425.2 0.8 1 20.1627.3 0.8 1.4 30.58Dichlorvos reassessment – application Page 132 <strong>of</strong> 436
4 Leafyvegetables(BBCH ≥50)4 Leafy + fruitingvegetables andpulses(BBCH 10-19)4 Leafy + fruitingvegetables andpulses(BBCH 20-49)4 Leafy + fruitingvegetables andpulses(BBCH ≥50)4 Leafyvegetables andpulses(BBCH 10-19)4 Leafy + fruitingvegetables andpulses(BBCH 10-19)4 Leafy + fruitingvegetables andpulses(BBCH ≥20)3 Fruitingvegetable andpulses(BBCH 10-49)3 Fruitingvegetables andpulses(BBCH ≥50)4 Fruitingvegetables andpulses(BBCH 10-49)4 Fruitingvegetables andpulses(BBCH ≥50)3 Fruitingvegetables(BBCH 71-89)4 Fruitingvegetables(BBCH 71-89)4 FruitingvegetablesSmallgranivorousbirdSmallomnivorousbirdSmallomnivorousbirdSmallomnivorousbirdmediumherbivorous/granivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallgranivorousbird8.2 0.8 1.4 9.1824 0.8 1.4 26.8822.9 0.8 1.4 25.658.6 0.8 1.4 9.6390.6 0.8 1.4 101.4726.8 0.8 1.4 30.0225.2 0.8 1.4 28.2224.7 0.8 1 27.667.4 0.8 1 5.9224.7 0.8 1.4 27.667.4 0.8 1.4 8.29frugivorous bird 49.4 0.8 1 39.52frugivorous bird 57.4 0.8 1.4 64.29frugivorous bird 49.4 0.8 1.4 55.33Dichlorvos reassessment – application Page 133 <strong>of</strong> 436
(BBCH 71-89)3 Bush &canefruit(BBCH 00-79)4 Bush &canefruit(BBCH 00-79)5 Orchard(spring/summer)5 Orchard(BBCH 10-19)5 Orchard(BBCH 20-39)5 Orchard(BBCH ≥40)5 Orchard(BBCH 10-19)5 Orchard(BBCH 20-39)5 Orchard(BBCH ≥40)6 Orchard(spring/summer)6 Orchard(BBCH 10-19)6 Orchard(BBCH 20-39)6 Orchard(BBCH ≥40)6 Orchard(BBCH 10-19)6 Orchard(BBCH 20-39)6 Orchard(BBCH ≥40)7 passionfruit(spring/SmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallinsectivorousbird52.2 0.8 1 41.7952.2 0.8 1.4 58.4646.8 2.052 1 96.035.9 2.052 1 12.114.4 2.052 1 9.032.2 2.052 1 4.5121.9 2.052 1 44.9416.4 2.052 1 33.658.2 2.052 1 16.8346.8 2.052 1.4 134.455.9 2.052 1.4 16.954.4 2.052 1.4 12.642.2 2.052 1.4 6.3221.9 2.052 1.4 62.9116.4 2.052 1.4 47.118.2 2.052 1.4 23.5646.8 1.026 1 48.02Dichlorvos reassessment – application Page 134 <strong>of</strong> 436
summer)7 passionfruit(BBCH 10-19)7 passionfruit(BBCH 20-39)7 passionfruit(BBCH ≥40)7 passionfruit(BBCH 10-19)7 passionfruit(BBCH 20-39)7 passionfruit(BBCH ≥40)8 passionfruit(spring/summer)8 passionfruit(BBCH 10-19)8 passionfruit(BBCH 20-39)8 passionfruit(BBCH ≥40)8 passionfruit(BBCH 10-19)8 passionfruit(BBCH 20-39)8 passionfruit(BBCH ≥40)SmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallinsectivorousbirdSmallgranivorousbirdSmallgranivorousbirdSmallgranivorousbird5.9 1.026 1 6.054.4 1.026 1 4.512.2 1.026 1 2.2621.9 1.026 1 22.4716.4 1.026 1 16.838.2 1.026 1 8.4146.8 1.026 1.4 67.225.9 1.026 1.4 8.474.4 1.026 1.4 6.322.2 1.026 1.4 3.1621.9 1.026 1.4 31.4616.4 1.026 1.4 23.568.2 1.026 1.4 11.78Additional details provided in EFSA (2008):1Crop type Table I.1 (Annex 1) and Appendix 102Species type Table I.1 (Annex 1) and Appendix 103Residue Unit Dose (90 th percentile) Table I.1 (Annex 1)4 Multiple application factor (90 th percentile) Table 1.1 and Appendix 155 DDD = daily dietary dosePlants, <strong>of</strong>f-target foliar exposureNo foliar exposure plant toxicity data were available to ERMA New Zealand, <strong>the</strong>re<strong>for</strong>e noexposure assessment was made.Dichlorvos reassessment – application Page 135 <strong>of</strong> 436
Plants and soil organisms, <strong>of</strong>f-target soil exposureMaximum application rates (Table C2) were used to calculate concentrations in soil adjacentto <strong>the</strong> application area. For <strong>of</strong>f-field deposition <strong>of</strong> <strong>the</strong> substances it was assumed that driftfrom a 1 ha treated area was evenly distributed over a 1 ha non-target area. It was assumedthat 9.7% <strong>of</strong> <strong>the</strong> active ingredient will drift outside <strong>the</strong> target area by airblast application,6.6% by ground application high boom (vegetables, cereals, berries, maize), and 2.9% byground boom application low boom (strawberries, pasture). These drift assumptions werebased on GENEEC2 modelling. Dichlorvos application to passionfruit is by knapsack sprayer,but GENEEC2 does not provide a drift assumption <strong>for</strong> knapsack application. As passionfruitis a vigorous, climbing vine that clings by tendrils to almost any support it was assumed that<strong>the</strong> drift is comparable with a ground application high boom (6.6%). Results are shown inTable C6 <strong>for</strong> dichlorvos.Table C6:Deposition dichlorvos <strong>of</strong>f-field<strong>Application</strong> scenario<strong>Application</strong> rate(kg ai/ha)% <strong>of</strong> applicationdriftingDeposition bydrift (kg/ha)Deposition(mg/m 2 )Airblast 2.052 9.7 0.199 19.9Ground (high boom) 0.8 6.6 0.053 5.3Ground (low boom) 0.8 2.9 0.023 2.3Knapsack 1.026 6.6 0.068 6.8Soil concentrations <strong>of</strong> <strong>the</strong> active ingredient are calculated by assuming <strong>the</strong> deposition wouldmix into <strong>the</strong> top 5 cm <strong>of</strong> soil, and this soil would have a bulk density <strong>of</strong> 1500 kg/m 3 , ie <strong>the</strong>deposition expressed in mg/m 2 would mix into 75 kg <strong>of</strong> soil.Deposition after 2 applications was calculated according to European guidance (EU, 2000):PEC multiple applications = PEC one application x (1- e -nki ) / (1-e –ki )Where <strong>for</strong> dichlorvosPEC = predicted environmental concentrationn = number <strong>of</strong> applications =2k= ln 2/ DT 50 (in days)i= interval between two consecutive applications in days= 7 daysDT 50 = half life soil in days = 1 daye = constant= 2.718The estimated soil concentrations <strong>of</strong> dichlorvos are shown in Table C8.Table C8:Soil concentration <strong>of</strong> dichlorvos<strong>Application</strong>scenarioSoil concentration <strong>of</strong>f field (mg/kg)Soil concentration in field (mg/kg)1 application 2 applications 1 application 2 applicationsAirblast 0.27 0.27 2.74 2.74Ground (highboom)0.07 0.07 1.07 1.07Dichlorvos reassessment – application Page 136 <strong>of</strong> 436
Ground (lowboom)0.03 0.03 1.07 1.07Knapsack 0.09 0.09 1.37 1.37Terrestrial invertebratesERMA New Zealand has used <strong>the</strong> Guidance from ESCORT Workshop 2 to estimate <strong>the</strong> infieldand <strong>of</strong>f-field exposure (Barrett et al 2000).In-field exposure is estimated using <strong>the</strong> <strong>for</strong>mula:In-field exposure = application rate x MAFWhere:application rate is in g/haMAF is a multiple application factor listed in <strong>the</strong> guidance document. Inaccordance with <strong>the</strong> guidance <strong>the</strong> MAF is not applied <strong>for</strong> bees, only <strong>for</strong> o<strong>the</strong>rnon-target invertebrates.The estimated in-field concentrations are shown in Table C9 <strong>for</strong> dichlorvosTable C9:Terrestrial invertebrates- in-field exposure dichlorvosCrop<strong>Application</strong> rate(g ai/ ha)<strong>Application</strong>frequencyMAF 1In-field exposure(g ai/ha)strawberries 800 1 1 800800 2 1.7 1360Vegetables, cereals,berries800 1 1 800800 2 1.7 1360Fruit (tree) 2052 1 1 20522052 2 1.7 3488passionfruit 1026 1 1 10261026 2 1.7 17441: MAF= multiple application factor. In <strong>the</strong> absence <strong>of</strong> field data, default values are used. For 2 applications <strong>the</strong> default is1.7For <strong>the</strong> <strong>of</strong>f-field exposure ERMA New Zealand used <strong>the</strong> <strong>for</strong>mula:Off field exposure = application rate x MAF x (drift factor/ vegetation distribution factor)Whereapplication rate is in g/ha or ml/haMAF is a multiple application factorThe drift factors used in <strong>the</strong> model differ from <strong>the</strong> drift factors in GENEEC2modelling. The values used were recommended <strong>for</strong> use with this model(Rautmann et al, 2001).Dichlorvos reassessment – application Page 137 <strong>of</strong> 436
The vegetation distribution factor estimates <strong>the</strong> interception <strong>of</strong> drift byvegetation. For a generic assessment a value <strong>of</strong> 1 was used corresponding to<strong>the</strong> worst case assessment <strong>of</strong> no interception.The estimated <strong>of</strong>f field concentrations are shown in Table C10 <strong>for</strong> dichlorvos.Table C10:Terrestrial invertebrates- <strong>of</strong>f field exposure dichlorvosCrop<strong>Application</strong>rate(g ai/ ha)<strong>Application</strong>frequencyMAF 1Drift factor(= % drift/100)VegetationdistributionfactorOff fieldexposure(g ai/ha)Strawberries,Vegetables,cereals, berries800 1 1 0.0277 1 22.16800 2 1.7 0.0238 1 32.37Fruit (tree) 2052 1 1 0.2920(earlyseason)0.1573 (laterin season)2052 2 1.7 0.2553(earlyseason)0.1213 (laterin season)passionfruit 1026 1 1 0.2920(earlyseason)0.1573 (laterin season)1026 2 1.7 0.2553(earlyseason)0.1213 (laterin season)1 599.18322.781 890.59423.141 299.59161.391 445.29211.571: MAF= multiple application factor. In <strong>the</strong> absence <strong>of</strong> field data, default values are used. For 2 applications <strong>the</strong> default is1.7.Dichlorvos reassessment – application Page 138 <strong>of</strong> 436
Appendix D: Ecotoxicity <strong>of</strong> dichlorvosNo evaluation <strong>of</strong> chronic toxicity has been made due to <strong>the</strong> rapid dissipation <strong>of</strong> dichlorvos in<strong>the</strong> environment.Table D.1:Aquatic toxicityAcute toxicityfishAcute toxicityinvertebrateSpecies and lifestage testedrainbow trout(Oncorhynchusmykiss)Rainbow trout(Oncorhynchusmykiss)Lake trout(Salvelinusnamacycush)Bluegillsunfish(Lepomismacrochirus)Bluegillsunfish(Lepomismacrochirus)Sheepsheadminnow(Cyprinodonvariegates)Sheepsheadminnow(Cyprinodonvariegates)Waterflea(Daphniapulex)Waterflea(Simocephalusserrulatus)Waterflea(Simocephalusserrulatus)Waterflea(Daphniamagna)Waterflea(Daphniamagna)Test substanceandconcentrationstestedTestmethodObservations andresults100 % ai 24 h LC 50 = 0.5 mg/L(supplemental)42 % ai 96 h LC 50 = 0.32 mg/L(supplemental)100% ai 96 h LC 50 = 0.183-0.187mg/L(supplemental)ReferenceUS EPA2006US EPA2006US EPA200698% ai 96 h LC 50 = 0.869 mg/L US EPA200642% ai 96 h LC 50 =1.86 mg/L(supplemental)US EPA200698% ai 96 h LC 50 =7.35 mg/L US EPA200642.39% ai 96 h LC 50 =6.146 mg/L US EPA2006100% ai 48 h EC 50 = 0.00007mg/L100% ai 48 h EC 50 = 0.00028mg/L(supplemental)100% ai 48 h EC 50 = 0.00026mg/L(supplemental)97/98% ai 48 h EC 50 = 0.00019mg/L99% ai 48 h LC 50 = 0.000085mg/LUS EPA2006EU 2003US EPA2006EU 2003US EPA2006EU 2005EU 2005Dichlorvos reassessment – application Page 139 <strong>of</strong> 436
eastern oyster(Crassostreavirginica)Mysid(Americamysisbahia)Mysid(Americamysisbahia)Anadaragranosa98% ai 96h EC 50 = 89.1 mg/L US EPA200698% ai 96 h EC 50 = 0.0191mg/L42% ai 96 h EC 50 = 0.0187mg/LUS EPA2006US EPA200691.17% ai 48 h LC 50 = 4.72 mg/L EU 2005Gammaruslacustris100% ai 96 h LC 50 = 0.0005mg/LEU 2005Toxicity toalgaegreen algae - 48 h EC 50 > 100 mg/L(supplemental)US EPA2006Unknownalgae- 48 h EC 50 = 14 mg/L(supplemental)US EPA2006Marine diatom - 48 h EC 50 = 17- 28mg/LSelenastrumcapricornutum(supplemental)US EPA200697-98% ai 94 h E r C 50 = 140 mg/L EU 2005Scenedesmussubspicatus98.1% ai 96 h E r C 50 = 160 mg/L EU 2005Scenedesmussubspicatus- 96 h EC 50 =52.8 mg/LbiomassproductionAPVMA2008Toxicity toaquatic vascularplantsNDAcute toxicitysedimentdwellingorganismsChironomusriparius(larvae)94% ai 24 h EC 50 = 0.00873mg/L withoutsedimentEC 50 = 0.0167mg/L withsedimentEU 2005ActivatedsludgeNDTable D.2:BioconcentrationSummary In<strong>for</strong>mationBioconcentrationBioconcentration factor (BCF) Log Kow = 1.47This indicates a low potential <strong>for</strong>ReferencePMRA,2008Dichlorvos reassessment – application Page 140 <strong>of</strong> 436
ioaccumulationClearance timeLevel <strong>of</strong> residues (%) in organisms after <strong>the</strong> 14day depuration phaseNDNDTable D.3:Acute oraltoxicity tomammalsAcute oraltoxicity to birdsTerrestrial vertebrate toxicitySpecies andlife stagetestedTest substance anddoses/concentrationstestedTestmethodObservations andresultsrat - LD 50 = 46.4mg/kgPheasant 93 % ai - LD 50 = 11.3mg/kgReferenceAPVMA,2008US EPA2006Bobwhitequail96.5% - LD 50 = 8.8 mg/kg US EPA2006Mallardduck93% - LD 50 = 7.78mg/kgUS EPA2006Dietary toxicityto birdsJapanesequailPekingduck14 d LD 50 = 6.6 mg/kg(not acceptable)7 d LD 50 = 10.8mg/kg(not acceptable)chicken 21 d LD 50 = 10.18mg/kgCommonpigeonChicken(whiteleghorn)(not acceptable)21 d LD 50 = 3.28mg/kg(not acceptable)24 h LD 50 = 6.45mg/kg(not acceptable)pheasant 94.8% 5 day LC 50 =568 mgai/kgEU 2005EU 2005EU 2005EU 2005EU 2005US EPA2006Mallardduck94.8% 5 day LC 50 =1317 mgai/kgUS EPA2006Mallardduck94.8% 5 day LC 50 >5000 mgai/kgUS EPA2006Dichlorvos reassessment – application Page 141 <strong>of</strong> 436
JapanesequailJapanesequailJapanesequailChicken(whiteleghorn)8 d LC 50 >75 mg/kgfood(not acceptable)8 d LC 50 >10 mg/kgfood(<strong>for</strong>mulation)(not acceptable)8 d LC 50 = 251mg/kg feed28 d LC 50 = 500mg/kg food(not acceptable)EU 2005EU 2005EU 2005EU 2005Table D.4:Toxicity to o<strong>the</strong>r soil dwelling organismsEffects on earthwormAcute toxicityField or semifieldtestsSpecies andlife stagetestedEiseniafetidaEiseniafetidaNDEffects on soil micro-organismsNitrogen mineralizationCarbon mineralisationActivated sludgeTerrestrial plantsSeedling emergenceVegetative vigourTest substance anddoses/concentrationstested0, 10, 18, 32, 56and 100 mg ai/kgsoilTestmethodObservations andresults14 d LC 50 = 14 mgai/kgNOEC = 10 mgai/kg- 14 d LC 50 = 80.9 mgai/kgTest substance anddoses/concentrations testedDichlorvos0, 1.5 and 13.4 mg ai/kg in loamand sand soil, 28 dDichlorvos0, 1.28 and 13.4 mg ai/kg in loamand humic sand soil, 28 dDichlorvos100 mg ai/L, 30 minNDNDNOEC < 12.3 mgai/kgObservationsand resultsNo effect on soilnitrification atconcentrations upto 13.4 mg ai/kg.No effect on soilmicrobial biomass(measured as soilrespiration) atconcentrations upto 13.4 mg ai/kg.EC 50 = 100 mgai/LReferenceEU 2005APVMA2008ReferenceEU 2005EU 2005EU 2005Dichlorvos reassessment – application Page 142 <strong>of</strong> 436
Table D.5:Toxicity to terrestrial invertebratesSpeciesand lifestagetestedEffects on honeybeesAcute oraltoxicityHoneybeeTest substance anddoses/concentrationstestedTestmethodObservationsand resultsdichlorvos - LD 50 = 0.029µg/ beeReferenceEU 2005AcutecontacttoxicityHoneybeedichlorvos - LD 50 = 0.495µg/ beedichlorvos - LD 50 = 0.065µg/ beeUS EPA 2006EU 2005Dichlorvos 100 EC 72 h LD 50 < 0.41 µg/beeEU 2005dichlorvos 24 h LD 50 = 0.6 µg/bee (estimation)EU 2005Field or semi-field testshoneybeedichlorvos LD 50 = 0.052-0.9 µg/ beeDichlorvos residueon foliageLD 50 = 0.2 kgai/ haAPVMA 2008APVMA 2008Effects on o<strong>the</strong>r arthropod speciesLaboratory testsPredatory mite(Phytoseiuluspersimilis)Ladybird(Curinuscoeruleus)Speciesand lifestageAdult,eggsadultTest substance anddoses/concentrationstestedDichlorvos 100 atdose rate <strong>of</strong> 100 g ai/100 LDichlorvos 0.08 kgai/haTestmethodExtendedlab test,roseleafletsLab test, 72hObservationsand resultsDichlorvos hadadverse effects on<strong>the</strong> development<strong>of</strong> <strong>the</strong> adults, noton that <strong>of</strong> larvae.ReferenceEU 200560% mortality EU 2005Dichlorvos reassessment – application Page 143 <strong>of</strong> 436
Environmental classificationOn <strong>the</strong> basis <strong>of</strong> <strong>the</strong>se ecotoxicity data, dichlorvos was classified <strong>for</strong> environmental endpointsas follows:Table D.6:Environmental classification <strong>of</strong> dichlorvosHazard Class/SubclassHazardclassificationMethod <strong>of</strong> classificationReferenceSubclass 9.1 9.1A Fish: bluegill sunfish LC 50 = 0.869mg/LCrustacean: Daphnia pulex EC 50 =0.00007 mg/LAlgae: Selenastrum capricornutumE r C 50 = 140 mg/LUS EPA 2006US EPA 2006EU 2005Subclass 9.2 9.2B Earthworm: LC 50 = 14 mg/kgEU 2005( EC 50 = 1.4 mg/kg)Subclass 9.3 9.3A ratLD 50 = 46.4 mg/kgBird: mallard duckAPVMA, 2008US EPA 2006LD 50 = 7.78 mg/kgSubclass 9.4 9.4A HoneybeeEU 2005LD 50 oral = 0.029 µg/beeLD 50 contact = 0.065 µg/beeDichlorvos reassessment – application Page 144 <strong>of</strong> 436
Appendix E: Risk Assessment: Environment dichlorvosIntroductionAn estimation <strong>of</strong> environmental risks has been made on <strong>the</strong> basis <strong>of</strong> available in<strong>for</strong>mation on<strong>the</strong> use <strong>of</strong> dichlorvos using standard modelling tools to estimate exposure concentrations incombination with <strong>the</strong> data on <strong>the</strong> ecotoxicity <strong>of</strong> <strong>the</strong> substance.For Class 9 substances, irrespective <strong>of</strong> <strong>the</strong> intrinsic hazard classification, <strong>the</strong> ecological riskcan be assessed <strong>for</strong> a substance or its components by calculating a risk quotient (RQ) based onmeasured or estimated exposure concentrations. Estimated exposure concentrations (EEC)are calculated taking into account use scenarios (including spray drift, application rates andfrequencies), and <strong>the</strong> fate <strong>of</strong> <strong>the</strong> product including half-lives <strong>of</strong> <strong>the</strong> component(s) in soil andwater. Dividing an EEC by <strong>the</strong> LC 50 or EC 50 generates an acute RQ whilst dividing <strong>the</strong> EECby <strong>the</strong> NOEC generates a chronic RQ as follows:Acute RQ = EEC Chronic RQ = EECLC 50 or EC 50NOECIf <strong>the</strong> RQ exceeds a predefined level <strong>of</strong> concern (see below), it may be appropriate to refine<strong>the</strong> risk assessment or apply controls to ensure that appropriate matters are taken into accountto minimise <strong>of</strong>f-site movement <strong>of</strong> <strong>the</strong> substance. Conversely, if a worst-case scenario is used,and <strong>the</strong> level <strong>of</strong> concern is not exceeded, <strong>the</strong>n in terms <strong>of</strong> <strong>the</strong> environment, <strong>the</strong>re is apresumption <strong>of</strong> low risk which is able to be adequately managed by existing controls.For <strong>the</strong> assessment <strong>of</strong> environmental effects <strong>of</strong> dichlorvos, no evaluation <strong>of</strong> chronicenvironmental risk has been made due to its rapid dissipation in <strong>the</strong> field.Levels <strong>of</strong> concern (LOC) developed by <strong>the</strong> USEPA (Urban & Cook, 1986), and adopted byERMA New Zealand, to determine whe<strong>the</strong>r a substance poses an environmental risk areshown in Table E.1.Table E.1:Levels <strong>of</strong> concern in environmental risk assessment <strong>for</strong> aquatic andterrestrial organismsAquatic (fish, invertebrates)Level <strong>of</strong> Concern(LOC)PresumptionAcute RQ ≥0.5 High acute riskPlants (aquatic and terrestrial)0.1–0.5 Risk can be mitigated through restricted use
TER= LD 50 / estimated environmental concentrationHQ bees = application rate/ LD 50HQ invertebrates = exposure/ LR 50Table E.2:Levels <strong>of</strong> concern in environmental risk assessment <strong>for</strong> terrestrial organismsBird/ earthwormLevel <strong>of</strong> Concern(LOC)PresumptionAcute TER 50Terrestrial invertebratesHQ < 2 Low riskHQ Higher tier < testing required≥2Aquatic organismsAcute risks to aquatic organisms are shown in Table E.3.Dichlorvos reassessment – application Page 146 <strong>of</strong> 436
Aquatic organsimsTable E.3:Environmental risk quotients <strong>for</strong> aquatic organsimsCompartmentExposuredurationExpected Environmental concentration (µg/L)(<strong>for</strong> Scenarios 1-8*)ReceptorEffectconcentra-tion(µg/L)Risk Quotient(<strong>for</strong> Scenarios 1-8*)1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8Freshwater Acute 9.7 9.8 10.2 10.3 27.1 27.5 13.0 13.2 Fish 870 0.011 0.011 0.012 0.012 0.031 0.032 0.015 0.015Invertebrates 0.07 139 140 146 147 387 393 186 189Plants 140000 0.00007 0.00007 0.00007 0.00007 0.00019 0.0002 0.00009 0.00009*Scenarios1 Strawberries, 1 application2 Strawberries, 2 applications3 Vegetables, cereals,berries, 1 application4 Vegetables, cereals,berries, 2 applications5 Fruit, 1 application6 Fruit, 2 applications7 Passionfruit, 1 application8 Passionfruit, 2 applicationsDichlorvos reassessment – application Page 147 <strong>of</strong> 436
Comparison <strong>of</strong> levels <strong>of</strong> concern (Table E.1) to <strong>the</strong> risk quotient in Table E.3 showshigh acute risk to invertebrates in <strong>the</strong> freshwater environment. The risks to fish andaquatic plants are low. This conclusion is based on Tier 0 modelling <strong>of</strong> exposure(GENEEC2).To explore risk reduction options, ERMA New Zealand used <strong>the</strong> AgDrift model toestimate <strong>the</strong> buffer zone that would reduce exposure through spray drift to aconcentration unlikely to cause acute toxicity. The receiving water was defined as a 30cm deep pond. Spray drift is only one route <strong>of</strong> exposure by which dichlorvos willcontaminate <strong>the</strong> aquatic environment, but given <strong>the</strong> rapid dissipation <strong>of</strong> dichlorvos itwill be important. The model indicated that even <strong>for</strong> <strong>the</strong> lowest application rate (800 gai/ha), a buffer zone > 304 meters is required to reduce <strong>the</strong> receiving waterconcentration to less than <strong>the</strong> lowest acute EC/LC 50 .GroundwaterTier 0 modelling <strong>of</strong> concentrations in groundwater predicts concentrations from 0.00069to 0.0036µg/L. In <strong>the</strong> EU, 0.1 µg/L is <strong>the</strong> concentration above which <strong>the</strong> predictedconcentration is considered to be unacceptable. As this level <strong>of</strong> concern is not exceededERMA New Zealand considers <strong>the</strong> risks <strong>for</strong> groundwater are low.BirdsThe avian toxicity assessment was per<strong>for</strong>med according to ―Risk Assessment to Birdsand Mammals (EFSA 2008)‖. The risk assessment is based on a TER (toxicity-exposureratio) approach. For pesticides in general, mortality is unlikely when TER ≥ 10 (acuterisk). No assessment <strong>of</strong> chronic risk was made due to <strong>the</strong> rapid dissipation <strong>of</strong>dichlorvos in <strong>the</strong> environment.Table E.4:Acute avian risk assessment – screening stepScenario Crop 1 IndicatorSpecies 2 LD 503DDD 4 TER 5 valueTrigger1 strawberries Small omnivorous bird 9.18 127.04 0.07
12345Crop type Table I.1 (Annex 1) and Appendix 10Species type Table I.1 (Annex 1) and Appendix 10Geometric mean if multiple species testedDDD = daily dietary doseToxicity-exposure ratio = LD 50 / Estimated environmental concentrationFor all scenarios <strong>the</strong> toxicity:exposure ratio triggers higher tier risk assessment.Table E.5:Acute avian risk assessment- first tier assessmentScenario Crop 1 IndicatorSpecies 2 LD 5031 Strawberry(BBCH 10-19)1 Strawberry(BBCH 20-39)1 Strawberry(BBCH ≥40)1 Strawberry(BBCH 10-19)1 Strawberry(BBCH ≥20)3 Cereals(BBCH 10-19)3 Cereals (BBCH 20-29)3 Cereals3 Cereals(BBCH 30-39)(BBCH ≥40)3 Leafy vegetables(BBCH 10-49)3 Leafy vegetables(BBCH ≥50)3 Leafy + fruitingvegetables and pulses(BBCH 10-19)3 Leafy + fruitingvegetables and pulses(BBCH 20-49)3 Leafy + fruitingvegetables and pulses(BBCH ≥50)3 Leafy vegetables andpulsesDDD 4 TER 5 TriggervalueSmall omnivorous bird 9.18 19.2 0.48
(BBCH 10-19)3 Leafy + fruitingvegetables and pulses(BBCH 10-19)3 Leafy + fruitingvegetables and pulses(BBCH ≥20)3 Fruiting vegetableand pulses(BBCH 10-49)3 Fruiting vegetablesand pulses(BBCH ≥50)3 Fruiting vegetables(BBCH 71-89)3 Bush &cane fruit(BBCH 00-79)5 Orchard(spring/summer)5 Orchard(BBCH 10-19)5 Orchard(BBCH 20-39)5 Orchard(BBCH ≥40)5 Orchard(BBCH 10-19)5 Orchard(BBCH 20-39)5 Orchard(BBCH ≥40)7 passionfruit(spring/summer)7 passionfruit(BBCH 10-19)7 passionfruit(BBCH 20-39)7 passionfruit(BBCH ≥40)7 passionfruit(BBCH 10-19)Small insectivorousbirdSmall insectivorousbird9.18 21.44 0.43
7 passionfruit(BBCH 20-39)7 passionfruit(BBCH ≥40)Small granivorous bird 9.18 16.83 0.55
Table E.8:Earthworm –TER in-field<strong>Application</strong>scenarioEarthwormacute toxicity14 d LC 50(mg/kg)Soil concentration in-field(mg/kg) both 1 and 2applicationsTER in-fieldAirblast 14 2.74 5
Fruit (tree) 2052 70759 >50Passionfruit 1026 35379 >50These HQ greatly exceed <strong>the</strong> critical HQ <strong>of</strong> 50. HQ values that exceed levels <strong>of</strong>concern may be refined using <strong>the</strong> results <strong>of</strong> higher tier testing such as semi-field andfield trials. However, no data from higher tier testing were available to ERMA NewZealand.ERMA New Zealand notes that in APVMA (2008) <strong>the</strong> results <strong>of</strong> a foliar residue studyare provided. The LD 50 value was reported to be 0.2 kg ai/ha, which is less than NewZealand application rates, but no o<strong>the</strong>r in<strong>for</strong>mation was available. By contrast, USEPA (2006) reports <strong>the</strong> results <strong>of</strong> a study on <strong>the</strong> toxicity <strong>of</strong> foliar residues to honey bees(guideline 141-2) using <strong>the</strong> typical end-use product. The study showed residues <strong>of</strong>dichlorvos 4E applied at 0.5 lb ai/A (= 0.56 kg ai/ha) were practically nontoxic to honeybees three hours post treatment.Terrestrial invertebrates (o<strong>the</strong>r than bees)No data are available to per<strong>for</strong>m a quantitative risk assessment. However, <strong>the</strong>re are twostudies on non-target invertebrates. The results <strong>of</strong> those tests show that dichlorvos hadadverse effects on <strong>the</strong> development <strong>of</strong> adult predatory mites (Phytoseiulus persimilis)and that 0.08 kg dichlorvos per ha caused 60% mortality <strong>of</strong> <strong>the</strong> ladybirds (Cuinuscoeruleus). Based on this in<strong>for</strong>mation and <strong>the</strong> mode <strong>of</strong> action <strong>of</strong> dichlorvos ERMA NewZealand expects dichlorvos to be toxic to a wide range <strong>of</strong> terrestrial non-targetinvertebrates coming in contact with <strong>the</strong> spray, vapours or fresh residue.Conclusions environmental risksERMA New Zealand concludes that <strong>the</strong> levels <strong>of</strong> concern are exceeded <strong>for</strong> aquaticorganisms, birds and terrestrial invertebrates. ERMA New Zealand also identified a risk<strong>for</strong> earthworms in <strong>the</strong> field when dichlorvos is applied by airblast equipment. Highertier modelling could potentially refine <strong>the</strong>se estimates <strong>of</strong> <strong>the</strong> risks but it is unlikely toreduce <strong>the</strong> risk quotients, particularly <strong>for</strong> <strong>the</strong> aquatic environment by <strong>the</strong> orders <strong>of</strong>magnitude required to remove <strong>the</strong> estimation <strong>of</strong> risks. There<strong>for</strong>e risk mitigationmeasures need to be considered.Buffer zones can be used to mitigate risks to <strong>the</strong> aquatic environment. However, <strong>for</strong>dichlorvos a buffer zone <strong>of</strong> more than 304 meters, <strong>the</strong> maximum calculated by <strong>the</strong>model, is needed to reduce <strong>the</strong> risk to an acceptable level. Buffer zones are notprotective <strong>of</strong> birds and terrestrial invertebrates that may move in and out <strong>of</strong> a crop.Timing <strong>of</strong> application to avoid times bees are <strong>for</strong>aging will reduce <strong>the</strong> risks to bees, butwould not reduce <strong>the</strong> risk to o<strong>the</strong>r non-target invertebrates that live within or adjacent tocrops.Dichlorvos reassessment – application Page 153 <strong>of</strong> 436
Restricting application rates or frequencies would be unlikely to reduce risks toacceptable levels due to <strong>the</strong> size <strong>of</strong> <strong>the</strong> risk quotients determined <strong>for</strong> even a singleapplication.Dichlorvos reassessment – application Page 154 <strong>of</strong> 436
Appendix F: Human Toxicity <strong>of</strong> dichlorvosDichlorvos (DDVP):Review <strong>of</strong> Toxicology and HSNO Classifications 6 and 8For:ERMA New Zealand20 Customhouse QuayPO Box 131WellingtonNEW ZEALANDPrepared by:Martin Edwards PhDToxicology Consulting Ltd36 Hastings ParadeDevonport 0624North Shore Cityedwardsm@ihug.co.nzVersion: 2.0 DraftJune 2009Dichlorvos reassessment – application Page 155 <strong>of</strong> 436
1 PURPOSE1.1 The purpose <strong>of</strong> this report is, <strong>for</strong> <strong>the</strong> Environmental Risk ManagementAuthority New Zealand (ERMA New Zealand) reassessment <strong>of</strong> dichlorvos(DDVP), to:review <strong>the</strong> toxicologyreview <strong>the</strong> HSNO Classifications 6 and 8propose AOEL(s)1.2 The key aspects to extract from <strong>the</strong> overseas regulatory reviews are:type <strong>of</strong> studyspecies/straintest materialdose levelsendpointremarks - findings (adverse effects)GLP/Test Guidelinereference (including date <strong>of</strong> original source)reliabilityjustificationwith any data gaps or endpoints with insufficient data clearly identified.1.3 The scope <strong>of</strong> <strong>the</strong> context used to <strong>for</strong>m this assessment is confined to <strong>the</strong>documents listed in <strong>the</strong> Reference section <strong>of</strong> this document, <strong>the</strong> timeconstraints, <strong>the</strong> pr<strong>of</strong>essional experience <strong>of</strong> <strong>the</strong> author, and <strong>the</strong> date thisdocument was issued.1.4 The assessment constitutes <strong>the</strong> whole document and <strong>the</strong> reference sources,and should only be used as a whole.1.5 In spite <strong>of</strong> all care taken, <strong>the</strong> reference material should be directlyconsulted to check <strong>the</strong> veracity <strong>of</strong> data, opinions and o<strong>the</strong>r material usedand attributed in this document.1.6 No responsibility will be taken <strong>for</strong> misuse <strong>of</strong> this document, or use bythird parties.Dichlorvos reassessment – application Page 156 <strong>of</strong> 436
CONTENTS:Title Page 11 Purpose 2Contents 32 <strong>Substance</strong> Identification 53 Toxicology Hazard Pr<strong>of</strong>ile – Introduction 64 Absorption, Distribution, Metabolism and Elimination (ADME) 94.1 Absorption 94.2 Distribution 124.3 Metabolism 134.4 Elimination 145 Acute Oral 6.1 166 Acute Dermal 6.1 197 Acute Inhalation 6.1 218 Skin Irritation 6.3 & Corrosion 8.2 259 Eye Irritation 6.4 & Corrosion 8.3 2710 Respiratory Sensitisation 6.5A 2911 Contact Sensitisation 6.5B 3012 Mutagenicity 6.6 3313 Carcinogenicity 6.7 4114 Reproductive Toxicity 6.8 5615 Developmental Toxicity 6.8 6316 Reproductive or Developmental Effects on or via Lactation 6.8C 6917 Specific Target Organ Toxicity 6.9: Single dose – oral 7118 Specific Target Organ Toxicity 6.9: Single dose – dermal 75Dichlorvos reassessment – application Page 157 <strong>of</strong> 436
19 Specific Target Organ Toxicity 6.9: Single dose – inhalation 7720 Specific Target Organ Toxicity 6.9: Repeat dose – oral 7921 Specific Target Organ Toxicity 6.9: Repeat dose – dermal 8622 Specific Target Organ Toxicity 6.9: Repeat dose – inhalation 8723 O<strong>the</strong>r Potential Toxic Endpoints 9123.1 Endocrine disruption 9123.2 Neurotoxicity 9223.3 Immunotoxicity 9724 Human Exposure Reports 9825 AOEL 10126 Summary & Conclusions 110References 115Appendix 1: Summary <strong>of</strong> benchmarks used in occupational risk assessments(APVMA, 2008b) 117Last Page 123Dichlorvos reassessment – application Page 158 <strong>of</strong> 436
2 SUBSTANCE IDENTIFICATIONIUPAC name:Chemical name (CAS):Common name:2,2-dichlorovinyl dimethylphosphate2,2-dichloroe<strong>the</strong>nyl dimethylphosphate;Phosphoric acid, 2,2-dichloroe<strong>the</strong>nyl dimethyl esterDichlorvos; DDVPCAS Registry number: 62-73-7Molecular <strong>for</strong>mula: C 4 -H 7 -Cl 2 -O 4 -PMolecular weight: 220.97Structural <strong>for</strong>mula:(ChemID; HSG 18, 1988)Vapour pressure: 0.0158 mm Hg = 2.1 Pa (CCID, 2009)Dichlorvos reassessment – application Page 159 <strong>of</strong> 436
3 TOXICOLOGICAL HAZARD PROFILE – INTRODUCTIONDichlorvos exerts its toxic effects by inhibiting neural acetylcholinesterase inhumans and animals. Throughout <strong>the</strong> central and peripheral nervous systemscholinergic synapses contain this enzyme, which is responsible <strong>for</strong> hydrolyzingacetylcholine released from <strong>the</strong> pre-synaptic terminal. Dichlorvos chemicallyreacts with <strong>the</strong> active site <strong>of</strong> acetylcholinesterase and inhibits enzyme activity.Inhibition <strong>of</strong> neural acetylcholinesterase allows acetylcholine to accumulate in <strong>the</strong>synapse, resulting in increased firing <strong>of</strong> <strong>the</strong> postsynaptic neuron or increasedneuroeffector activity. Increased cholinergic activity in <strong>the</strong> parasympa<strong>the</strong>ticautonomic nervous system (muscarinic receptors) can include increasedsalivation, lacrimation, perspiration, miosis, nausea, vomiting, diarrhea, excessivebronchial secretions, bradycardia, frequent micturition, and incontinence.Increased neuroeffector activity on skeletal muscles (nicotinic receptors) caninclude muscle fasciculations, cramps, muscle weakness, and depolarization-typeparalysis. Effects on central nervous system (predominantly muscarinic) includedrowsiness, fatigue, mental confusion, headache, convulsions, and coma. Theseclassical symptoms <strong>of</strong> organophosphate neurotoxicity increase in severity andrapidity <strong>of</strong> onset in a dose-dependent manner (Ecobichon 1991). (Originals notsighted in APVMA, 2008a)Erythrocytes also contain acetylcholinesterase, erythrocyte (or RBC)acetylcholinesterase. Both neural and erythrocyte acetylcholinesterase areproduced by <strong>the</strong> same gene (Taylor et al., 1993). Erythrocyte and neuralacetylcholinesterase in in vitro systems are inhibited to roughly <strong>the</strong> same extent byexposure to dichlorvos (Hayes 1982). Erythrocyte acetylcholinesterase is used as asurrogate measurement <strong>of</strong> <strong>the</strong> inhibition <strong>of</strong> neural acetylcholinesterase. The liverproduces a cholinesterase that circulates in <strong>the</strong> blood. This cholinesterase, calledserum (or plasma) cholinesterase, is also inhibited by dichlorvos and is ano<strong>the</strong>rmarker <strong>for</strong> exposure. Usually, this enzyme is inhibited by dichlorvos at lower levels<strong>of</strong> exposure than required to inhibit neural or erythrocyte acetylcholinesterase(Hayes 1982). (Originals not sighted; ATSDR, 1997)Dichlorvos has high acute toxicity in experimental animals. Clinical signs <strong>of</strong> toxicityoccur soon after dosing and are typical <strong>of</strong> organophosphate poisoning (exophthalmus,salivation, lachrymation, tremors, dyspnoea, convulsions and death). Survivors recovercompletely within 24 hours (Durham et al., 1957; Lamb 1992). The time to peak effectin rats following oral dosing is 15-60 minutes (Tyl et al., 1990a; Lamb 1992; Lamb1993b). (Originals not sighted; APVMA, 2008a)There is an extensive genotoxicity database <strong>for</strong> dichlorvos. Negative results werereported in in vivo host-mediated, dominant lethal, sister chromatid exchange andmicronucleus assays (except on skin after local application at cytotoxic doses).Dichlorvos was reported not to induce in vivo chromosomal aberrations in bone-marrowcells, spermatocytes or spermatogonia (Dean & Thorpe, 1972a; Moutschen-Dahmen etal., 1981; Degraeve et al., 1984b), DNA strand breaks (Wooder & Creedy, 1979) orunscheduled DNA syn<strong>the</strong>sis (Mirsalis et al., 1989; Bed<strong>for</strong>d, 1991). (Originals notsighted; WHO, 1993)Dichlorvos reassessment – application Page 160 <strong>of</strong> 436
However, dichlorvos has genotoxic potential at localised high concentrations and in <strong>the</strong>absence <strong>of</strong> metabolism, demonstrated by micronucleus <strong>for</strong>mation in mouse epidermalkeratinocytes after direct application <strong>of</strong> dichlorvos to <strong>the</strong> skin; an increase in <strong>the</strong>mutation frequency in <strong>the</strong> liver <strong>of</strong> transgenic mice following repeated intraperitonealinjection; and, an increased incidence <strong>of</strong> hair follicle nuclear aberrations (NA) in CD1mice after a single application at 1/8 th <strong>the</strong> dermal LD 50 (non-guideline method).Dichlorvos was mutagenic and DNA-reactive in bacteria and o<strong>the</strong>r microorganisms invitro, in both <strong>the</strong> presence and absence <strong>of</strong> exogenous metabolic activation (althougheffects were commonly reduced in <strong>the</strong> presence <strong>of</strong> exogenous metabolic activation).Dichlorvos was also mutagenic and clastogenic in a range <strong>of</strong> mammalian cells exposedin vitro, including induction <strong>of</strong> UDS but not chromosomal aberrations or SCE incultured human cells.Dichlorvos is an electrophile and stated to possess a structural alert <strong>for</strong>methylating activity. While dichlorvos possesses methylating activity, <strong>the</strong>phosphorous atom <strong>of</strong> <strong>the</strong> molecule is reported to be a stronger electrophile than<strong>the</strong> methyl carbon atoms (phosphorylating reactivity). In tissues and blood,dichlorvos is much more likely to react with “A”-type esterases, serumcholinesterase, or acetylcholinesterase than with DNA (ATSDR, 1997; APVMA,2008a).There<strong>for</strong>e, dichlorvos is mutagenic and clastogenic at <strong>the</strong> point <strong>of</strong> contact, whereunchanged dichlorvos may be in direct contact with tissue [DDVP‘s inherent potential].There is no evidence that dichlorvos has any systemic genotoxic potential, due to <strong>the</strong>substance‘s inherent phosphorylating reactivity and <strong>the</strong> highly efficientbiotrans<strong>for</strong>mation [low risk].Dichlorvos revealed an increased incidence <strong>of</strong> adenomas <strong>of</strong> <strong>the</strong> exocrine pancreas inmale F344/N rats (2-year dietary study) indicated some evidence <strong>of</strong> carcinogenicactivity <strong>of</strong> dichlorvos, as did <strong>the</strong> increased incidences <strong>of</strong> <strong>for</strong>estomach squamous cellpapillomas in male and female B6C3F 1 mice (2-year dietary study). While <strong>for</strong>estomachtumours are not considered directly relevant to humans, <strong>the</strong>se findings (and <strong>the</strong>mutagenic potential in certain contact scenarios) indicate that repeated exposure to highconcentrations <strong>of</strong> dichlorvos poses some carcinogenic hazard.Dichlorvos revealed no evidence <strong>of</strong> particular reproductive or developmental toxicity,with adverse effects only noted at maternotoxic doses.The APVMA (2008a) summarised:―Dose-related inhibition <strong>of</strong> plasma, RBC and brain ChE activities was <strong>the</strong>most common manifestation <strong>of</strong> dichlorvos toxicity in short-term, subchronicand chronic studies in mice, rats and dogs. Cholinergic signs and occasionalmortalities occurred in rats and dogs at <strong>the</strong> same doses as <strong>the</strong> inhibition <strong>of</strong>brain ChE activity. Plasma and RBC ChE activities were also inhibitedfollowing chronic inhalational exposure in rats (LOEC = 0.5 mg/m 3 ; Blair etal., 1974 & 1976). There was little indication that repeated oral orinhalational exposure had any effect on haematology, clinical chemistry orDichlorvos reassessment – application Page 161 <strong>of</strong> 436
urinary parameters, or on organ weights or gross pathology. In some rat anddog studies, histopathology revealed cytoplasmic vacuolisation <strong>of</strong> <strong>the</strong> liver(Jolley et al., 1967; Wi<strong>the</strong>rup et al., 1967; Chan 1989).‖ (Originals notsighted; APVMA, 2008a)Dichlorvos reassessment – application Page 162 <strong>of</strong> 436
4 ABSORPTION, DISTRIBUTION, METABOLISM AND ELIMINATION (ADME)Dichlorvos is a relatively small, lipid-soluble molecule that can be absorbed bypassive diffusion through <strong>the</strong> lungs, gastrointestinal tract, or skin. Dichlorvosappears to be rapidly absorbed by <strong>the</strong> oral and dermal routes <strong>of</strong> exposure.Dichlorvos is difficult to assay in biological tissues, so this rapid rate <strong>of</strong> absorptionis inferred from <strong>the</strong> time to onset <strong>of</strong> clinical signs and/or cholinesterase inhibition.The rapid degradation <strong>of</strong> dichlorvos by tissue esterases, particularly in <strong>the</strong> liverand <strong>the</strong> serum contribute to <strong>the</strong> assay difficulties. The half-life <strong>of</strong> dichlorvos inhuman blood in vitro is about 10 minutes (Blair et al., 1975). Dichlorvos does notappear to have preferential distribution to particular tissues, to be stored orconcentrated in any tissue. Esterase-catalysed degradation <strong>of</strong> dichlorvos producesdimethyl phosphate and dichloroacetaldehyde. Dimethyl phosphate is excreted in<strong>the</strong> urine, while dichloroacetaldehyde can be reduced to dichloroethanol ordehalogenated to glyoxal, which enters 2-carbon metabolism pool. Dichloroethanolis ei<strong>the</strong>r conjugated to glucuronic acid and excreted in <strong>the</strong> urine or dehalogenatedand fur<strong>the</strong>r metabolised. Dichlorvos can also be demethylated in a glutathionedependentreaction. (Originals not sighted; ATSDR, 1997)4.1 Absorption:OralCalDRP (1996) reported:―DDVP ( 14 C- and 32 P-labelled, 10 mg/kg [b.w.], 78 and 67-78% purity,respectively) was rapidly absorbed following gavage administration toalbino rats (strain not specified) (Casida et al., 1962).‖ (Originals notsighted; CalDPR, 1996)The ATSDR (1997) reported:“When 5 mg [vinyl- 14 C]dichlorvos was ingested in orange juice by amale volunteer, 27% <strong>of</strong> <strong>the</strong> dose was recovered from expired air as14 CO, (Hutson and Hoadley 1972b). Dichlorvos was detected (0.18mg/L) in <strong>the</strong> blood <strong>of</strong> fetuses 5 minutes after oral administration <strong>of</strong> 6mg/kg [b.w.] dichlorvos in sunflower oil to 5 pregnant rabbits on <strong>the</strong>day <strong>of</strong> delivery (Maslinska et al., 1979). A total <strong>of</strong> 38.2% <strong>of</strong> <strong>the</strong> [l- 14 C-vinyl]dichlorvos (40 mg/kg [b.w.] in PVC pellets) was absorbed in 9young male Yorkshire pigs (Potter et al., 1973a), <strong>the</strong> remainder wasrecovered in <strong>the</strong> pellets. In ano<strong>the</strong>r experiment, where [l-14 Cvinylldichlorvos was mixed with feed, absorption <strong>of</strong> dichlorvos wasdemonstrated by <strong>the</strong> recovery <strong>of</strong> 4% <strong>of</strong> <strong>the</strong> radioactivity in <strong>the</strong> urine,5% in <strong>the</strong> feces, and 6.6% in <strong>the</strong> expired air (Potter et al., 1973b).“Small amounts (ppb) <strong>of</strong> organosoluble [ 32 P] (presumably dichlorvos ordesmethyl dichlorvos) was detected in <strong>the</strong> milk <strong>of</strong> a lactating cow after<strong>the</strong> oral administration <strong>of</strong> 1 mg/kg [b.w.]/day [ 32 P]dichlorvos <strong>for</strong> 7 daysfollowed by a dose <strong>of</strong> 20 mg/kg [b.w.] on day 8 in gelatin capsulesDichlorvos reassessment – application Page 163 <strong>of</strong> 436
(Casida et al., 1962). Dichlorvos was effectively absorbed in 6 male and6 female rats following <strong>the</strong> oral administration <strong>of</strong> 3.6 mg/kg [b.w.][methyl- 14 C]dichlorvos in arachis oil as indicated by <strong>the</strong> recovery <strong>of</strong>64.6% <strong>of</strong> <strong>the</strong> dose in urine (Hutson and Hoadley 1972a). Identicalrecovery was obtained in 6 male and 6 female mice given 22 mg/kg[b.w.] [methyl-14C]dichlorvos (Hutson and Hoadley 1972a). When[vinyl- 14 C]dichlorvos was administered orally to 2 male Syrianhamsters at a dose <strong>of</strong> 3.7 mg/kg [b.w.] and to a female at a dose <strong>of</strong> 1.5mg/kg [b.w.], it was rapidly absorbed and 11.9-21.8% <strong>of</strong> <strong>the</strong> dose wasrecovered in <strong>the</strong> urine.“Evidence <strong>for</strong> rapid absorption <strong>of</strong> dichlorvos by <strong>the</strong> oral route includesdeath <strong>of</strong> Swiss mice within 9 minutes after a single gavage dose <strong>of</strong> 150mg/kg [b.w.] (Mohammad et al. 1989) and in crossbred swine within15-30 minutes receiving 100-560 mg/kg [b.w.] in an LD50 study(Stanton et al., 1979). Signs <strong>of</strong> cholinergic toxicity (vomiting, diarrhea)were observed in greyhound dogs within 7-15 minutes <strong>of</strong> receiving 11mg/kg [b.w.] dichlorvos by gelatin capsule (Snow and Watson 1973).(Originals not sighted; ATSDR, 1997)InhalationCalDRP (1996) reported:―In a comparison study with <strong>the</strong> oral route <strong>of</strong> exposure, rats (male, strain notgiven) were exposed to DDVP (0.71-1.07 mg in vapor) <strong>for</strong> 1 hour by noseonlyinhalation (Hutson et al., 1971). Urine, feces, exhaled air, and tissueswere collected following <strong>the</strong> same protocol as <strong>the</strong> oral route. The actualadministered dose was unknown since DDVP adsorbed to <strong>the</strong> apparatus.There<strong>for</strong>e, results were expressed as <strong>the</strong> percentage <strong>of</strong> <strong>the</strong> total recoveredyield <strong>of</strong> carbon dioxide, <strong>the</strong> major metabolite. The amount <strong>of</strong> radioactivityretained in <strong>the</strong> tissues was similar to those <strong>for</strong> <strong>the</strong> oral route with <strong>the</strong> highestradioactivity level in <strong>the</strong> liver. The rates and routes <strong>of</strong> excretion, and urinarymetabolites by <strong>the</strong> inhalation route were considered similar to those afteroral administration.‖ (Originals not sighted; CalDPR, 1996)The ATSDR (1997) reported:“Indirect evidence <strong>for</strong> absorption <strong>of</strong> dichlorvos following inhalation inhumans was obtained by measuring dichloroethanol, a specificdichlorvos metabolite, in <strong>the</strong> urine <strong>of</strong> a male volunteer (Hutson andHoadley 1972b). This individual was exposed at <strong>the</strong> extremely highlevel <strong>of</strong> 38 mg/m3 (4.2 ppm) <strong>for</strong> 105 minutes. The first urine sampleobtained after exposure ended was analyzed by gas-liquidchromatography and 0.42 μg dichloroethanol/mL urine was detected(Hutson and Hoadley 1972b). The dichlorvos metabolite dimethylphosphate was found in <strong>the</strong> urine <strong>of</strong> 3 <strong>of</strong> 13 male volunteer pesticideapplicators who applied dichlorvos during an 8-hour workday (Das etal., 1983). During <strong>the</strong> application, <strong>the</strong>y wore goggles, caps, respirators,coats, gloves, and shoes. Each applicator sprayed 4 homes using 10-14Dichlorvos reassessment – application Page 164 <strong>of</strong> 436
aerosol cans (230-330 g dichlorvos) and 18-22 pints <strong>of</strong> 0.5% emulsionspray (40-50 g dichlorvos). A range <strong>of</strong> 0.32-l .39 μg <strong>of</strong> dimethylphosphate was measured in <strong>the</strong> urine <strong>of</strong> 3 workers. No effect was seenin clinical parameters or plasma cholinesterase activities. Dichlorvoswas not detected (detection limit was 1 μg/g) in <strong>the</strong> blood <strong>of</strong> 2 malevolunteers immediately after exposure to air concentrations <strong>of</strong> 0.25mg/m 3 (0.03 ppm) <strong>for</strong> 10 hours or to 0.7 mg/m3 (0.08 ppm) <strong>for</strong> 20hours (Blair et al., 1975). Low-level exposure and breakdown byesterases may account <strong>for</strong> nondetection <strong>of</strong> dichlorvos.” (Originals notsighted; ATSDR, 1997)The APVMA (2008b) reported:Dermal―A study (Kirkland, 1971) evaluated by <strong>the</strong> WHO (1988) demonstrated thatat dichlorvos concentrations <strong>of</strong> 0.1 – 2.0 mg/m 3 , [anaes<strong>the</strong>tised andtracheotomised] pigs retained 15 – 70% <strong>of</strong> <strong>the</strong> inhaled dichlorvos.‖(APVMA, 2008b)The APVMA (2008a) reported:― 14 C-dichlorvos (in water) was applied to <strong>the</strong> shaved backs <strong>of</strong> 12 rats/dose at3.6, 36 or 360 μg/animal (rates <strong>of</strong> 0.5, 3 and 30 μg/cm 2 , respectively). Theapplication site was 12 cm 2 and <strong>the</strong> total volume applied to each rat was 100μL. A substantial proportion <strong>of</strong> 14 C-dichlorvos (38-55%) evaporated from<strong>the</strong> skin surface following application. The total level <strong>of</strong> dermal absorptionwas 22-30% and was consistent over time and dose (0.5-30 g/cm 2 ).Absorption occurred within <strong>the</strong> first 10 hours <strong>of</strong> sample application, with<strong>the</strong> actual amount <strong>of</strong> 14 C-dichlorvos absorbed increasing with dose. Theexcretion routes were via exhaled air (CO 2 ) (2.2-4.9%), urine (1-2%) andfaeces (0.1-0.6%). Blood levels decreased over time. Analysis <strong>of</strong> <strong>the</strong>stability <strong>of</strong> <strong>the</strong> test material lacked transparency and was somewhat difficultto follow in <strong>the</strong> study report. (Jeffcoat 1990).‖ (Originals not sighted;APVMA, 2008a)CalDRP (1996) reported <strong>the</strong> same study:―DDVP ( 14 C, 93% purity; 0, 0.3, 3.0, or 30 ug/cm 2 ) was applied dermally onrats (Jeffcoat, 1990). After 10 hours <strong>of</strong> exposure, <strong>the</strong> percent <strong>of</strong> dermalabsorption (determined by radioactivity in <strong>the</strong> carcass, blood, exhaled air,urine, feces, and cage rinses) ranged from 7.3 to 13.3% <strong>for</strong> all doses. Therewas no fur<strong>the</strong>r absorption after 10 hours and up to 120 hours. The majority<strong>of</strong> <strong>the</strong> applied dose (37.7- 51.6%) was lost to evaporation and trapped by acharcoal impregnated covering placed over <strong>the</strong> area. Washing <strong>of</strong> <strong>the</strong>exposed skin with soapy water removed 8.4-14.7% <strong>of</strong> <strong>the</strong> administereddose. Based on <strong>the</strong> results <strong>of</strong> this study, <strong>the</strong> DPR Worker Health and SafetyBranch recommended a dermal absorption factor <strong>of</strong> 13% <strong>for</strong> <strong>the</strong> estimation<strong>of</strong> potential human exposure.‖ (Originals not sighted; CalDPR, 1996)Dichlorvos reassessment – application Page 165 <strong>of</strong> 436
The US EPA (2006) reported that:4.2 Distribution:―The dermal absorption rate <strong>for</strong> dichlorvos was estimated to beapproximately 11% in 10 hours <strong>of</strong> exposure based on an acceptable dermalabsorption study in rats (MRID 41435201).‖ [MRID 41435201 is Jeffcoat,A. (1990) Dermal Absorption <strong>of</strong> Dichlorvos in Rats: Lab Project Number:4615. Unpublished study prepared by Research Triangle Institute. 196 p.]CalDRP (1996) reported:―Rats (Crl:CD (SD) BR) were given DDVP ( 14 C, purity not specified) ei<strong>the</strong>ras a single intravenous dose (1 mg/kg [b.w.]), by gavage as a single dose(0.8 mg/kg [b.w.] or 21 mg/kg [b.w.]), or by gavage as multiple doses (0.8mg/kg [b.w.]) <strong>for</strong> 16 days (Cheng, 1989 and 1991). Radioactivity in <strong>the</strong>tissues and carcasses was determined 7 days after dosing. Urine, feces, andexhaled air as CO 2 were monitored <strong>for</strong> 7 days after dosing. Clinical signs,such as tremors and salivation, were observed 2.5 hours after gavage dosingin <strong>the</strong> 21 mg/kg [b.w.] group. There were no differences in <strong>the</strong> tissuedistribution and excretion patterns between <strong>the</strong> dosing regiment or sexes.Consistent with <strong>the</strong> earlier studies, <strong>the</strong> liver and kidneys contained higherlevels <strong>of</strong> radioactivity than o<strong>the</strong>r organs (lung, spleen, uterus, and bone). Forboth routes <strong>of</strong> administration, <strong>the</strong> percent <strong>of</strong> total dose excreted ranged from40 to 58% in <strong>the</strong> exhaled air, 10-17% in <strong>the</strong> urine, and 4-7% in <strong>the</strong> feces.The majority <strong>of</strong> <strong>the</strong> radioactivity in <strong>the</strong> exhaled air and excreta waseliminated within 24 hours after dosing. The major metabolites in <strong>the</strong> urineand feces were hippuric acid and urea. Glucuronide conjugates and o<strong>the</strong>rdehalogenated products were not positively identified.‖ (Originals notsighted; CalDPR, 1996)The APVMA (2008a) reported:―Blair et al. (1975) examined <strong>the</strong> tissue distribution <strong>of</strong> dichlorvos inmammals following inhalational or intravenous administration. Rats wereexposed to dichlorvos vapour at 0.05 or 0.5 mg/m 3 (in open chambers <strong>for</strong> 14days), 50 mg/m 3 <strong>for</strong> 2-4 h[ours], or 10 or 90 mg/m3 <strong>for</strong> 4 h[ours] (head-onlyexposure). In addition, two male human subjects were exposed in a 20 m 3chamber to atmospheres containing 0.25 mg/m 3 dichlorvos <strong>for</strong> 10 h[ours] or0.7 mg/m 3 <strong>for</strong> 20 h[ours]. A separate group <strong>of</strong> rats was given a singleintraperitoneal injection <strong>of</strong> 0.83 mg/kg bw dichlorvos. No dichlorvos wasdetected in ei<strong>the</strong>r <strong>of</strong> <strong>the</strong> two male subjects. At low concentrations (
4.3 Metabolism:found in tissues <strong>of</strong> rats exposed to 10 mg/m3 <strong>for</strong> 4 h[ours], or in blood ortissues exposed to 0.05 or 0.5 mg/m 3 <strong>for</strong> 14 days. Following intravenousinjection, little or no dichlorvos was found in rat liver, fat, testes or brain.Dichlorvos was detected in blood in only one <strong>of</strong> three rats at 10 and 30 minpostdose. Overall, <strong>the</strong> results indicated that dichlorvos was rapidlymetabolised in vivo.‖ (Originals not sighted; APVMA, 2008a)CalDRP (1996) reported:―After absorption, <strong>the</strong> primary site <strong>of</strong> metabolism was <strong>the</strong> liver, and <strong>the</strong>metabolism <strong>of</strong> DDVP was rapid. At 0.25 hour after treatment, <strong>the</strong> tissues(liver, kidneys, and blood) contained primarily hydrolysis products and lessthan 5% as DDVP. Radioactivity was also found in <strong>the</strong> bone which is likelydue to <strong>the</strong> deposition <strong>of</strong> phosphoric acid in <strong>the</strong> bone. Routes <strong>of</strong> excretion <strong>for</strong>DDVP were exhaled air, urine, and feces. After 24 hours, <strong>the</strong> percentage <strong>of</strong>radioactivity in <strong>the</strong> exhaled air as CO 2 was 16%. Urinary metabolitesincluded desmethyl DDVP, mono- and dimethyl phosphates, inorganicphosphate, and dichloroethyl glucuronide. Over 80% <strong>of</strong> <strong>the</strong> radioactivity in<strong>the</strong> urine collected 3 hours after treatment were mono- and dimethylphosphates. Only about 10% <strong>of</strong> <strong>the</strong> dose excreted in <strong>the</strong> feces was watersoluble DDVP derivatives. O<strong>the</strong>r metabolites included inorganic phosphate,two-carbon fragments (glycine and serine), phosphate ions, and chlorideions.‖ (Originals not sighted; CalDPR, 1996)The APVMA (2008a) reported:―Hutson et al. (1971) investigated <strong>the</strong> metabolic fate <strong>of</strong> [ 14 C-vinyl]dichlorvos in rats following oral, inhalational and intraperitonealexposure. Respired air accounted <strong>for</strong> <strong>the</strong> greatest proportion <strong>of</strong> eliminated14 C and most was recovered within 24 hours following inhalationalexposure (head only). After 4 days, <strong>the</strong> highest tissue levels occurred in <strong>the</strong>carcass and skin (~38 and 26%, respectively <strong>of</strong> <strong>the</strong> total amount <strong>of</strong> 14CO 2 ).Analysis <strong>of</strong> metabolites following oral dosing with [ 14 C-vinyl]-labelled or[ 36 Cl]-labelled dichlorvos detected free 36 Cl and at least 7 metabolites.Identified metabolites included hippuric acid (8.3%), desmethyl dichlorvos(10.9%) and dichloroethanol glucuronide (27%). The presence <strong>of</strong>dichloroacetaldehyde could not be demonstrated. No parent compound wasidentified. The majority <strong>of</strong> 14 C in <strong>the</strong> livers from rats given a single oral dose<strong>of</strong> [ 14 C-vinyl]dichlorvos was detected in <strong>the</strong> protein fraction (as glycine andserine). Urinary metabolites detected following intraperitonealadministration <strong>of</strong> [ 14 C-vinyl]dichlorvos included hippuric acid anddesmethyl dichlorvos (2-5%) and dichloroethanol glucuronide (76%).Following inhalational exposure, identifiable urinary metabolites alsoincluded hippuric acid (9.3%) and desmethyl dichlorvos (4.3%), and urea(5.3%). No unchanged dichlorvos was found in <strong>the</strong> urine following dosingby ei<strong>the</strong>r <strong>the</strong> oral or inhalational routes.‖ (Originals not sighted; APVMA,2008a)Dichlorvos reassessment – application Page 167 <strong>of</strong> 436
4.4 Elimination:CalDRP (1996) reported:―Rats (strain not specified) were given DDVP ( 14 C and 36 Cl, purity notspecified; 0.99 mg/male rat and 0.72 mg/female rat) by gavage (Hutson etal., 1971). Urine, feces, and exhaled air were collected every day <strong>for</strong> 4 days.Radioactivity in tissues was also determined. Additional female rats wereused <strong>for</strong> <strong>the</strong> determination <strong>of</strong> metabolites in <strong>the</strong> urine and <strong>the</strong> liver. Therewas no difference in <strong>the</strong> excretion patterns between sexes. After 4 days(daily result not given), <strong>the</strong> percentages <strong>of</strong> administered doses in <strong>the</strong> urine,feces, and exhaled air were 12.8-18.2%, 3.4-4.8%, 36.8-38.8%, respectively.The identified urinary metabolites included hippuric acid (8.3% <strong>of</strong> totalurinary radioactivity), desmethyl-DDVP (10.9%), and 2,2-dichloroethyl-Bd-glucopyranosiduronicacid (27%), while no unmetabolized DDVP,dichloroacetaldehyde or dichloroacetic acid was found. Of <strong>the</strong> tissuesexamined, <strong>the</strong> highest level <strong>of</strong> radioactivity (4.4-5.0% <strong>of</strong> dose) was in <strong>the</strong>liver. Analysis <strong>of</strong> <strong>the</strong> liver tissue showed that 75% <strong>of</strong> <strong>the</strong> radioactivity wasassociated with glycine, serine, and cystine in <strong>the</strong> protein hydrolysatefraction.‖ (Originals not sighted; CalDPR, 1996)The APVMA (2008a) reported:―In a series <strong>of</strong> experiments, [ 14 C-vinyl]dichlorvos was given by gavage tomale and female mice (0.2 mg, approximately 8 mg/kg bw), and Syrianhamsters (0.22-0.56 mg, approximately 4 mg/kg bw), and to 1 man orally (5mg in 100 mL orange juice, approximately 70 μg/kg bw) and ano<strong>the</strong>r byinhalation (38 mg/m3 unlabelled dichlorvos <strong>for</strong> 105 min). Elimination ratesand urinary excretion were compared with results obtained from a secondexperiment using rats. Overall, <strong>the</strong> data indicated that <strong>the</strong> rates and routes <strong>of</strong>elimination were largely similar (predominantly air and urine) in all speciesand <strong>the</strong>re was no marked sex difference in laboratory animals. Followingoral dosing <strong>of</strong> mice and rats with [ 14 C-methoxy]dichlorvos, <strong>the</strong> majorurinary metabolite was dimethyl phosphate (~70% <strong>of</strong> urinary radioactivityand 40% <strong>of</strong> <strong>the</strong> dose). Desmethyl dichlorvos constituted 4% <strong>of</strong> total urinaryradioactivity in rats and 28% in mice. Minor metabolites present at less than2% <strong>of</strong> total urinary radioactivity were S-methyl-L-cysteine (both species),S-methyl-L-cysteine oxide and methylmercapturic acid (mouse only), andmethylmercapturic acid S-oxide (rat only). Two o<strong>the</strong>r minorchromatographic peaks could not be identified. Following oral dosing with[ 14 Cvinyl] dichlorvos hippuric acid, desmethyl dichlorvos and urea weredetected in <strong>the</strong> urine <strong>of</strong> mice and <strong>the</strong> man, with only hippuric acid measuredin hamsters. A dichloroethanol conjugate in <strong>the</strong> urine <strong>of</strong> <strong>the</strong> man exposed todichlorvos by inhalation was detectable but not quantifiable because <strong>of</strong>interference from endogenous peaks. (Hutson and Hoadly 1972a & b)‖(Originals not sighted; APVMA, 2008a)―Cheng (1989 & 1991) examined <strong>the</strong> metabolism and tissue distribution <strong>of</strong>[vinyl-1- 14 C] dimethyl dichlorovinylphosphate ( 14 C-dichlorvos) in rats. Fiverats/sex/group were administered 14 C-dichlorvos as a single intravenousDichlorvos reassessment – application Page 168 <strong>of</strong> 436
dose <strong>of</strong> 1.0 mg/kg bw, a single gavage dose <strong>of</strong> 0.8 or 21.0 mg/kg bw, or 15daily oral gavage doses <strong>of</strong> 0.8 mg/kg bw unlabelled dichlorvos followed bya single radiolabelled dose <strong>of</strong> 0.8 mg/kg bw on <strong>the</strong> 16th day. The controlgroup consisted <strong>of</strong> 2 untreated rats. The major route <strong>of</strong> excretion was viaexhaled CO 2 (40-58%) followed by <strong>the</strong> urine (10-15%) and faeces (4-7%).Excretion was rapid, occurring within <strong>the</strong> first 24 hours after dosing.Marked levels <strong>of</strong> 14 C (13-26%) remained in <strong>the</strong> carcass seven days afterdosing. Relatively low levels <strong>of</strong> 14 C were found in o<strong>the</strong>r tissues such as <strong>the</strong>liver (3.5-4.8%), blood (0.3-0.5%) and kidneys (0.2-0.5%). Excretion andtissue distribution appeared to be independent <strong>of</strong> dose route and sex. Severalradioactive metabolites were detected in urine, including urea (19-33%) andhippuric acid (3.78-19.5%). In faeces, numerous uncharacterised minormetabolites were detected in addition to hippuric acid (
5 ACUTE ORAL 6.1HSNO Classification: Acute oral - 6.1BKEY STUDY:• Type <strong>of</strong> study: LD 50 ;• Species:• Strain:• Sex/Numbers:Rat;Tif:RAI;5/sex/group;• Test Material: Dichlorvos tech. (purity/source unstated) in 2%carboxymethylcellulose (CMC);• Dose levels:• Endpoint:• Remarks:• LD 50 (mean) =• GLP:• Test Guideline:31.7 to 100 mg/kg b.w. by gavage;Observations <strong>for</strong> morbidity, mortality, injury & clinicalsigns were conducted. Necropsy examinations wereper<strong>for</strong>med on all animals found dead and all survivinganimals at <strong>the</strong> scheduled terminal necropsy;Adverse signs included dyspnoea, exophthalmus, curvedposition, trismus, tonic-clonic muscle spasms and ruffledfur, with <strong>the</strong>se signs occurring at all dose levels within 2hours <strong>of</strong> administration. These signs increased in severitywith dose. All survivors recovered within 4 days. Grossexamination revealed no treatment-related changes.46.4 mg/kg b.w. (40.1-53.7 mg/kg b.w.), calculated byprobit analysis;No in<strong>for</strong>mation;No in<strong>for</strong>mation;• Reference source: Ciba-Geigy Ltd, Basle (1973) ―Acute oral LD 50 <strong>of</strong>technical dichlorvos (G177) in <strong>the</strong> rat.‖Toxicology/pathology PH 2.635. Report number Siss 3361Report date: 30 th August 1973. (Original not sighted.)(APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Ciba-Geigy (1973) is not stated to have beenconducted to GLP or Test Guidelines, however <strong>the</strong> LD 50 value is in line with o<strong>the</strong>rDichlorvos reassessment – application Page 170 <strong>of</strong> 436
eports. LD 50 = 46.4 mg/kg b.w. is in Category 6.1B as stated in Table 10.1 <strong>of</strong> <strong>the</strong>User Guide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).BACKGROUND:The APVMA (2008a) reported:―Durham WF, Gaines TB, McCauley RH, Sedlak VA, Mattson AM & Hayes WJjr (1957) Studies on <strong>the</strong> toxicity <strong>of</strong> 0, 0-dimethyl-2,2-dichlorovinyl phosphate(DDVP). Arch Ind Health 15: 340-349. This published paper reported on a series<strong>of</strong> experiments that investigated a number <strong>of</strong> endpoints as well as acute oraltoxicity in rats. Dichlorvos was prepared in-house at <strong>the</strong> Technical DevelopmentLaboratories <strong>of</strong> <strong>the</strong> Communicable Disease Centre, Public Health Service, USDepartment <strong>of</strong> Health, Education and Welfare. In<strong>for</strong>mation on <strong>the</strong> purity <strong>of</strong> <strong>the</strong>test material was not provided. Dichlorvos was given in peanut oil by gavage witha dose volume <strong>of</strong> 5 mL/kg bw to groups <strong>of</strong> white Sherman rats (group size notreported). LD50 values were 80 mg/kg bw (95% CI 62-104 mg/kg bw) in malesand 56 mg/kg (48-65 mg/kg bw) in females respectively. All animals that died didso within 1 h <strong>of</strong> dosing and complete recovery was observed in survivors within24 h. Adverse signs included bulging eyes, lachrymation, sialorrhoea, generalisedmuscle fasciculations and tremors. Convulsions were observed in some animalsprior to death. There was no apparent weight loss amongst survivors. Necropsyand pathology were not reported.‖ (Original not sighted; APVMA, 2008a)WHO (1992) reported:Acute oral toxicity <strong>of</strong> dichlorvos (WHO, 1988)SpeciesLD 50 (mg/kg b.w.)Mouse 68-275Rat 30-110Rabbit 13-23Cat 28Dog 100-316Chicken 15Swine 157Dichlorvos reassessment – application Page 171 <strong>of</strong> 436
The ATSDR (1997) reported:“A number <strong>of</strong> oral exposure LD50 studies have been done with dichlorvos inrats and mice. Based on reported LD50 values, dichlorvos is considered to be<strong>of</strong> moderate to high acute toxicity (WHO 1988). In <strong>the</strong> most extensive study<strong>of</strong> this type, dichlorvos was one <strong>of</strong> 5 chemicals used in a study designed toinvestigate how well an experimentally derived LD50 value would predict <strong>the</strong>level that would result in 1% lethality (LDl value) <strong>for</strong> CD-l mice (Haley et al.,1975). The LD50 <strong>for</strong> male mice in this study was calculated to be 139 mg/kg[b.w.], and <strong>the</strong> LD50 <strong>for</strong> females was 133 mg/kg [b.w.]. In a subsequent studyat lower doses, <strong>the</strong> LDl <strong>for</strong> <strong>the</strong> male mice was 84 mg/kg [b.w.] (predicted LDlwas 81 mg/kg [b.w.]). In <strong>the</strong> female mice, <strong>the</strong> LDl was 95 mg/kg [b.w.](predicted LDl was 106 mg/kg [b.w.]). The authors fur<strong>the</strong>r estimated an LD0.1<strong>of</strong> 70 mg/kg [b.w.] <strong>for</strong> male mice and 82 mg/kg [b.w.] <strong>for</strong> female mice. AnLD50 <strong>of</strong> 110 mg/kg [b.w.] was reported in male ICR mice (Takahashi et al.,1987). Dichlorvos administered by gavage in water at a dose <strong>of</strong> 150 mg/kg[b.w.] to male Swiss mice caused 100% lethality within 9 minutes(Mohammad et al., 1989).―In Sherman rats, oral LD50 values <strong>of</strong> 80 mg/kg [b.w.] in males and 56 mg/kg[b.w.] in females were reported (Durham et al., 1957). The LD 50 <strong>for</strong> female Wistarrats was reported to be 58.8 mg/kg [b.w.] (Gajewski and Katkiewicz 1981) and inmale Fischer 344 rats 97.5 mg/kg [b.w.] (Ikeda et al., 1990). Crossbred pigsweighing 12-27 kg treated with dichlorvos in gelatin capsules were reported tohave an LD50 <strong>of</strong> 157 mg/kg [b.w.] (Stanton et al., 1979).‖ (Original not sighted;ATSDR, 1997)Dichlorvos reassessment – application Page 172 <strong>of</strong> 436
6 ACUTE DERMAL 6.1HSNO Classification: Acute dermal – 6.1BKEY STUDY:• Type <strong>of</strong> study: LD 50 ;• Species:• Strain:• Sex/Numbers:• Test Material:• Dose levels:Rat;Sherman;Unstated number/sex/group;Dichlorvos tech. (purity/source unstated) in xylene;Unstated levels to clipped skin;• Endpoint: Mortality (LD 50 );• Remarks: All rats killed by a single dermal dose died within 20minutes <strong>of</strong> dosage, except a male dosed at 110 mg/kgb.w. that survived <strong>for</strong> 40 minutes and ano<strong>the</strong>r maledosed at 125 mg/kg b.w. that survived <strong>for</strong> 17 days.The symptoms <strong>of</strong> poisoning observed were bulgingeyes, lacrimation, sialorrhea [excessive salivation],muscle fasciculations, and tremors. Some animals hadconvulsions just be<strong>for</strong>e death. Rats that survivedappeared to make a full recovery.• LD50 =• GLP:• Test Guideline:75 mg/kg b.w. in females; 107 mg/kg b.w. in males;No in<strong>for</strong>mation;No in<strong>for</strong>mation;• Reference source: Durham WF, Gaines TB, McCauley RH, et al. 1957.“Studies on <strong>the</strong> toxicity <strong>of</strong> O,O-dimethyl-2,2-dichlorovinyl phosphate (DDVP).” AMA Arch IndHealth 15:340-349. (Original not sighted.) (ATSDR,1997);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Durham et al. (1957) was not conducted to GLP, andno Test Guideline is reported (but pre-dated such requirements). However, <strong>the</strong> LD 50value is in line with o<strong>the</strong>r reports. LD 50 = 75 mg/kg bw is in Category 6.1B as statedDichlorvos reassessment – application Page 173 <strong>of</strong> 436
in Table 10.1 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNOAct (ERMA, 2008).BACKGROUND:The APVMA (2008a) reported:―Tierfarm, Sissel, Switzerland (1969b) Report on <strong>the</strong> determination <strong>of</strong> <strong>the</strong> acutedermal LD 50 to <strong>the</strong> rat <strong>of</strong> DDVP technical. No Study/Report No. Lab/Sponsor:unspecified. Report date 10th July 1969. Dichlorvos (purity and source not given)was applied as a concentrate or dissolved in PEG (10% v/v) to a 10 cm 2 area <strong>of</strong><strong>the</strong> shaved back <strong>of</strong> RAC rats (6/sex/group) at doses in <strong>the</strong> range 80-200 mg/kgbw. The skin was occluded with aluminium foil and sticking plaster <strong>for</strong> 24 h[our]be<strong>for</strong>e washing with warm water, and animals were observed <strong>for</strong> 7 days afteradministration. The LD 50 (males plus females) was 210 mg/kg bw, with mostdeaths occurring after 24 h[our]. No adverse signs were observed at 80 or 100mg/kg bw (in PEG). At 150 or 200 mg/kg bw (concentrate), adverse signs wereobserved within 15-30 minutes <strong>of</strong> application and included dose-dependenttrismus, tonic-clonic spasms <strong>of</strong> limb muscles, prostration, exophthalmus,dyspnoea, and lachrymation and secretion from <strong>the</strong> Hardersche (Harderian)glands. Symptoms persisted <strong>for</strong> up to 3 days but surviving animals recovered fullyafter 5-6 days. Necropsy <strong>of</strong> animals dying during <strong>the</strong> observation period revealedacute liver, spleen and kidney congestion, bloated intestines and inflamedperitoneum. Animals sacrificed after 7 days showed enlarged livers, and bloatedor slack intestines. No o<strong>the</strong>r macroscopic effects were reported. No skin irritationwas evident.‖ (Original not sighted; APVMA, 2008a)WHO (1992) reported:Acute dermal toxicity <strong>of</strong> dichlorvos (WHO, 1988)SpeciesRatThe ATSDR (1997) reported:LD 50 (mg/kg b.w.)75-107 (24 hours)Rabbit 205“In ano<strong>the</strong>r LD50, study where dichlorvos was applied to female Wistar rats inethanol-water on depilated skin, an LD50 <strong>of</strong> 70.4 mg [/kg b.w.] dichlorvos wasfound (Gajewski and Katkiewicz 1981).” (Only details available, original notsighted; ATSDR, 1997)Dichlorvos reassessment – application Page 174 <strong>of</strong> 436
7 ACUTE INHALATION 6.1HSNO Classification: Acute inhalation - 6.1BKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test Material:LC 50 (4 hours, head-only); vapour/aerosol;Rat;Wistar (Bor:WISW);5 (vapour) or 10 (aerosol)/sex/group;Dichlorvos (98.7 % pure, batch no. 809 436 388, lot no.3379);• Dose levels: Vapour: 342 mg/m 3 (nominal), 116 mg/m 3 (analysed) <strong>for</strong> 4hours;Aerosol: 230-1926 mg/m 3 <strong>for</strong> 4 hours;• Endpoint: Mortality (LC 50 );• Remarks:For <strong>the</strong> vapour experiment, 5 animals/sex were exposed <strong>for</strong>4 hours to a nominal concentration <strong>of</strong> 342 mg/m 3 (<strong>the</strong>analysed concentration was 116 mg/m 3 , <strong>the</strong> maximumachievable as vapour). All animals showed adverse signsincluding bristling and ungroomed coat, reduced motilityand high gait but <strong>the</strong>re were no deaths. No effects onweight gain were observed during <strong>the</strong> 14-day observationperiod and autopsy revealed no treatment-related grosseffects.A lethal vapour concentration could not be generated(maximum concentration was 116 mg/m 3 ); LC 50 > 116mg/m 3 (0.116 mg/L).In <strong>the</strong> aerosol experiment, 10 animals/sex were exposed tonominal air concentrations <strong>of</strong> 1500 - 15000 μL/m 3 (230-1926 mg/m 3 ) <strong>for</strong> 4 hours, with <strong>the</strong> particle mass mediandiameter ranging from 2.8 to 6.4 μm. Adverse signs,evident immediately after exposure (i.e. when rats wereremoved from tubes) were severe muscle tremors andweakness, convulsions, recumbence on side, ataxia, apathyand dyspnoea. More persistent signs included ungroomedcoat, bristling fur and high gait. All surviving animalsappeared to behave normally during <strong>the</strong> second week <strong>of</strong>observation. Body weight gain was normal. Animals thatdied during exposure showed a number <strong>of</strong> changes atDichlorvos reassessment – application Page 175 <strong>of</strong> 436
autopsy: distended lung; oedematous and pale, patchy liverwith lobulation; pale spleen and kidney; hyperaemia <strong>of</strong> <strong>the</strong>glandular stomach and serosa <strong>of</strong> <strong>the</strong> small intestine; andblood and mucus in <strong>the</strong> gut. No treatmentrelated grosseffects were observed in those animals surviving <strong>the</strong> 14-day observation period.• LC 50 (aerosol) = 523 mg/m 3 (95% CI 435-632) (0.523 mg/L) <strong>for</strong> males;447 mg/m 3 (379-529) (0.447 mg/L) in females;• GLP:Yes;• Test Guideline: Stated con<strong>for</strong>ming to OECD [403?];• Reference source:• Reliability:Pauluhn J (1984) ―Dichlorvos (L15/20, DDVP) study <strong>for</strong>acute inhalation toxicity.‖ Report No. 13124;Lab/Sponsor: Bayer AG Institute <strong>of</strong> Toxicology,Wuppertal-Eberfeld. Report date: 12th December 1984.(Original not sighted.) (APVMA, 2008a);Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification:Pauluhn J (1984) was stated to have been conductedto GLP and Test Guideline, with <strong>the</strong> APVMA concluding that <strong>the</strong> quality wasadequate to have confidence in <strong>the</strong> LC 50 values. The LC 50 values are in line witho<strong>the</strong>r reports. LC 50 (mist) = 0.447 mg/L is in Category 6.1B (as a mist) as stated inTable 10.1 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act(ERMA, 2008).BACKGROUND:The APVMA (2006a) reported:―Durham WF, Gaines TB, McCauley RH, Sedlak VA, Mattson AM & Hayes WJJr (1957) Studies on <strong>the</strong> toxicity <strong>of</strong> 0, 0-dimethyl-2,2-dichlorovinyl phosphate(DDVP). Arch Ind Health 15: 340-349.―Weanling Sherman rats (10/sex/group) were maintained <strong>for</strong> two weeks in Peet-Grady chambers that had previously been sprayed once with an emulsioncontaining 2.5% dichlorvos at a rate <strong>of</strong> approximately 100 or 195 mg dichlorvosper square foot (ie. equivalent to 9.29 or 18.12 mg/m 3 ). Air levels <strong>of</strong> dichlorvos in<strong>the</strong> chamber sprayed at <strong>the</strong> lower rate ranged from 6 mg/m 3 at <strong>the</strong> start and 0.1mg/m 3 at <strong>the</strong> end <strong>of</strong> <strong>the</strong> two-week period. No adverse signs or body weightchanges were observed. Plasma and RBC ChE activities were slightly (
measured and it was not possible to determine <strong>the</strong> inhaled dose from <strong>the</strong> datapresented. Animals were supplied with food but not water and were removed from<strong>the</strong> chambers <strong>for</strong> 1 h[our]/day when water was supplied. Incoming and exhaust airwas monitored <strong>for</strong> dichlorvos by measuring total phosphorus. All animals in alltrials exposed to dichlorvos in <strong>the</strong> air died, with symptoms including slowlaboured respiration, sialorrhoea and paleness <strong>of</strong> ears and feet. Under <strong>the</strong> mostsevere exposure, <strong>the</strong>se signs appeared within 2 h[ours], with average survival time6.9 and 10.1 h[ours] in males and females respectively.―Kimmerle G (1966) Letter re. DDVP (Lo-No. 271) inhalation study. Bayer AGInstitute <strong>of</strong> Toxicology, 56 Wuppertal-Elberfeld. Ref. Dr.Ki/Sp dated 7thDecember 1966.―A single-page note reported on <strong>the</strong> LC 50 <strong>of</strong> dichlorvos in male rats (<strong>the</strong> sourceand purity <strong>of</strong> dichlorvos and strain <strong>of</strong> rat were not provided). Groups <strong>of</strong> 20animals were exposed to analysed dichlorvos aerosol concentrations <strong>of</strong> 0.209-1.244 mg/L <strong>for</strong> 1 h[our], or 0.063-0.544 g/L <strong>for</strong> 4 h[ours]. In addition, 2 groups <strong>of</strong>rats received (<strong>the</strong>oretical) 0.049 or 0.109 mg/L <strong>for</strong> 4 h[ours]/d[ay] <strong>for</strong> 5consecutive days. The 1-h[our] LC 50 was 0.455 mg/L (455 mg/m3), and <strong>the</strong> 4-h[our] LC 50 was 0.340 mg/L (340 mg/m3). Adverse signs were observed in 3/20rats at 0.319 mg/L and in most animals exposed to 0.479 mg/L or more <strong>for</strong> 1 h,and in all animals exposed to 0.082 mg/L or more <strong>for</strong> 4 h[ours]. There were noclinical signs and no animals died in <strong>the</strong> repeat-dose section <strong>of</strong> <strong>the</strong> study.―Macdonald R (1982) Toxicology <strong>of</strong> consumer products: <strong>the</strong> acute (4 h)inhalation toxicology <strong>of</strong> dichlorvos in rats and mice. Document No SBGR.82.145.Lab: Shell Research Ltd, Sittingbourne, UK. Sponsor: Temana. Report date:March 1982 QA study.―Groups <strong>of</strong> 10 animals (5/sex, CF1 mice and Wistar rats, both from Shell'sTunstall Laboratory) were subjected to head-only exposure to vapour containingdichlorvos (Windmill Plastics Ltd; batch No. ST82/016; 97.8% purity) <strong>for</strong> 4h[ours]. Observations on health and behaviour were made during and <strong>for</strong> 14 daysafter exposure. All mice exposed to 218 mg/m 3 (<strong>the</strong> only dose tested) survived.Adverse signs were body tremors and lethargy, with 3 mice displaying hind limbparesis and all showing splayed gaits. The clinical signs reversed by <strong>the</strong> secondday. In male rats, 3/10 animals exposed to 250 mg/m 3 (saturated air) died while all10 animals exposed to 210 mg/m 3 died. Subsequent exposure to 142 and 85mg/m 3 resulted in one male death at <strong>the</strong> lowest concentration. Two fur<strong>the</strong>rexperiments were per<strong>for</strong>med, using concentrations <strong>of</strong> 206 and 198 mg/m 3 , with nodeaths observed. Adverse signs in rats were observed at <strong>the</strong> highestconcentrations, and included ataxia and hypersensitivity to noise, both clearingrapidly after exposure. Lethargy persisted <strong>for</strong> up to 3 days in survivors. Dead ratsshowed signs <strong>of</strong> respiratory failure but no treatment-related effects were seen insurvivors sacrificed after 14 days. In conclusion, <strong>the</strong> LC 50 (4 h[our]) <strong>for</strong>dichlorvos in mice was >218 mg/m 3 and in rats was >206 mg/m 3 . Considerablevariability was evident, with all animals exposed to 210 mg/m 3 dying but nodeaths observed at 206 mg/m 3 .‖ (Originals not sighted; APVMA, 2006a)WHO (1992) reported:Dichlorvos reassessment – application Page 177 <strong>of</strong> 436
Acute inhalation toxicity <strong>of</strong> dichlorvos (WHO, 1988)Species Mode <strong>of</strong> exposure Time <strong>of</strong> exposure(hours)LC 50 (μg/L)Mouse Whole body 4 13Head only 4 > 218Rat Whole 4 15Whole 1 140Head 4 340Head 1 455Head 4 > 198Dichlorvos reassessment – application Page 178 <strong>of</strong> 436
8 SKIN IRRITATION 6.3 & CORROSION 8.2HSNO Classification: Skin irritation – 6.3BKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test Material:• Dose levels:• Endpoint:• Remarks:Primary dermal irritation;Rabbit;Hacking and Churchill, New Zealand White (HC:NZW);3/group (sex unstated);Dichlorvos (batch no. 809 436 455, 97.3% pure);500 μL <strong>for</strong> 4 hours;Skin reactions (ery<strong>the</strong>ma and oedema);Groups <strong>of</strong> 3 HC:NZW rabbits (from Hacking andChurchill, Huntingdon, UK) were shorn over areas <strong>of</strong> <strong>the</strong>irflanks and exposed to 2.5 x 2.5 cm cellulose squares towhich water (control) or 500 μL dichlorvos (batch no. 809436 455, 97.3% pure) had been applied. After 4 hours <strong>the</strong>dressings were removed and areas washed with water; skinreactions where scored after 1, 24, 48 and 72 hours, and 7and 14 days.Easily perceptible redness (ery<strong>the</strong>ma grade 2) and slightswelling (oedema grade 1) were identified in all threerabbits during <strong>the</strong> first 48 hours after exposure. Thisdeclined in 2 rabbits to ery<strong>the</strong>ma grade 1 after 7 days butincreased to grade 3 (moderate) in <strong>the</strong> third. After 14 daysthis rabbit showed slight ery<strong>the</strong>ma (grade 1) with no o<strong>the</strong>reffects evident in o<strong>the</strong>r animals.[The mean Draize score (ery<strong>the</strong>ma) ≥ 1.77 ≤ 2.1]Overall, dichlorvos was slightly irritating to rabbit skin;• GLP:No in<strong>for</strong>mation;• Test Guideline: OECD 404;• Reference source:Pauluhn J (1985) ―L 15/20 (DDVP) technical activeingredient (c.n. dichlorvos): Study <strong>for</strong> irritant/corrosiveeffect on skin and eye (rabbit).‖ Report No. 13500.Lab/Sponsor: Bayer AG Institute <strong>of</strong> Toxicology,Dichlorvos reassessment – application Page 179 <strong>of</strong> 436
Wuppertal-Elberfeld. Report date: 22nd May 1985.(Original not sighted.) (APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Pauluhn J (1985) was conducted to Test Guideline,but <strong>the</strong> GLP status was not confirmed. The mean Draize score (ery<strong>the</strong>ma) wasgreater than <strong>the</strong> minimum threshold <strong>for</strong> 6.3B as stated in Section 11.2 <strong>of</strong> <strong>the</strong> UserGuide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).BACKGROUND:Cal DPR (1996) reported that DDVP technical was a ―mild‖ dermal irritant to rabbits.WHO (1988) reported:―A primary skin irritation test on dichlorvos was per<strong>for</strong>med by using male NewZealand white rabbits. Irritation observed on <strong>the</strong> skin after <strong>the</strong> application <strong>of</strong> 5 -20% water solutions <strong>of</strong> dichlorvos was relatively severe compared with thatcaused by o<strong>the</strong>r organophosphorus insecticides (Arimatsu et al., 1977).‖ (Originalnot sighted in WHO, 1988)Dichlorvos reassessment – application Page 180 <strong>of</strong> 436
9 EYE IRRITATION 6.4 & CORROSION 8.3HSNO Classification: Eye irritation – 6.4AKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test Material:• Dose levels:• Endpoint:• Remarks:Primary eye irritation;Rabbit;Hacking and Churchill, New Zealand White (HC:NZW);6/group (sex unstated);Dichlorvos (batch no. 809 436 455, 97.3% pure);100 μL <strong>for</strong> 24 hours;Ocular reactions (irritation <strong>of</strong> <strong>the</strong> cornea, iris andconjunctiva);100 μL <strong>of</strong> dichlorvos was applied to <strong>the</strong> conjunctival sac<strong>of</strong> one eyelid <strong>of</strong> 6 rabbits, <strong>the</strong> eyelid was held shut <strong>for</strong> onesecond [and released] and washed with saline 24 hourslater. Cornea and iris findings were obtained optically, and<strong>the</strong> corneal area affected was determined using a drop <strong>of</strong>1% fluorescein applied to <strong>the</strong> eye after 24 hours.Adverse signs were observed in all rabbits immediatelyafter administration. These included miosis, muscularfasciculations, tremor, staggering gait and recumbence onstomach, cyanosis, hyper salivation, tachypnoea andbronchosecretion. One male rabbit died 25 minutes afteradministration. Corneal opacity was evident, graded aslight and affecting up to 3/4 <strong>of</strong> <strong>the</strong> cornea, in all rabbitsduring <strong>the</strong> first 72 hours. Conjunctival redness andswelling, and increased tear flow was also observed in allanimals, generally graded as slight to pronounced (grade 1-3). Little effect on <strong>the</strong> iris reaction to light was observed.All surviving animals had recovered within 14-21 daysafter administration.Under <strong>the</strong> conditions <strong>of</strong> this study, dichlorvos was a severeeye irritant in rabbits;• GLP:No in<strong>for</strong>mation;• Test Guideline: OECD 405;Dichlorvos reassessment – application Page 181 <strong>of</strong> 436
• Reference source:• Reliability:Pauluhn J (1985) ―L 15/20 (DDVP) technical activeingredient (dichlorvos): Study <strong>for</strong> irritant/corrosive effecton skin and eye (rabbit).‖ Report No. 13500. Lab/Sponsor:Bayer AG Institute <strong>of</strong> Toxicology, Wuppertal-Elberfeld.Report date: 22nd May 1985. (Original not sighted.)(APVMA, 2008a);Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Pauluhn J (1985) was conducted to Test Guideline,but <strong>the</strong> GLP status was not confirmed. The level <strong>of</strong> reported injury was more than<strong>the</strong> minimum threshold as stated in Section 12.2 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholdsand Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).BACKGROUND:Cal DPR (1996) reported that DDVP technical was a ―mild‖ eye irritant to rabbits.Dichlorvos reassessment – application Page 182 <strong>of</strong> 436
10 RESPIRATORY SENSITISATION 6.5AHSNO Classification: Respiratory sensitisation – Insufficient dataKEY STUDY: None.BACKGROUND:No appropriate studies or o<strong>the</strong>r relevant data were reported by APVMA (2008a), WHO(1988 & 1993), Cal DPR (1996) or ATSDR (1997) in <strong>the</strong>ir reassessments <strong>of</strong> dichlorvos.Dichlorvos reassessment – application Page 183 <strong>of</strong> 436
11 CONTACT SENSITISATION 6.5BHSNO Classification: Contact sensitisation – 6.5BKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Number:• Test Material:• Dose levels:• Endpoint:• Remarks:Maximisation Test;Guinea pig;Dunkin-Hartley;9 females/group;Dichlorvos (source, purity unstated);Induction: 25% dichlorvos;Challenge: 0.005, 0.05 or 0.5% dichlorvos;Skin reactions (ery<strong>the</strong>ma and oedema);Nine Dunkin-Hartley female guinea pigs (300-400 g b.w.)were induced topically with 25% dichlorvos <strong>under</strong>occluded conditions. Animals were <strong>the</strong>n challenged with0.005, 0.05 or 0.5% dichlorvos and any skin reactionsscored at 24 and 48 hours according to <strong>the</strong> procedure <strong>of</strong>Kligman (1966).At 24 hours post-challenge, 0, 56 and 100% <strong>of</strong> guinea pigstested positive at 0.005, 0.05 or 0.5% dichlorvos,respectively, decreasing to 0, 22 and 67%, respectively, at48 hours. There was a dose-related increase in <strong>the</strong> grade <strong>of</strong><strong>the</strong> reaction.Dichlorvos is concluded to be a skin sensitiser in guineapigs;• GLP:• Test Guideline:No in<strong>for</strong>mation;No in<strong>for</strong>mation;• Reference source: Ueda A, Aoyama K, Manda F, Ueda T & Kawahara Y(1994) ―Delayed-type allergenicity <strong>of</strong> tri<strong>for</strong>ine (Saprol®).‖Contact Dermititis 31:140-145. (Original not sighted.)(APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Dichlorvos reassessment – application Page 184 <strong>of</strong> 436
Justification <strong>for</strong> Classification: Ueda et al. (1994) was a published study, althoughTest Guideline and GLP status were not reported. The positive response rate wasmore than <strong>the</strong> minimum threshold as stated in Section 13.2 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong>Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008), so dichlorvosshould be classified 6.5B <strong>for</strong> contact sensitisation.BACKGROUND:The APVMA (2008a) reported:―Ueda A, Aoyama K, Manda F, Ueda T & Kawahara Y (1994) Delayed-typeallergenicity <strong>of</strong> tri<strong>for</strong>ine (Saprol®). Contact Dermititis 31:140-145.“Humans: The delayed-type allergenicity <strong>of</strong> seven pesticides (tri<strong>for</strong>ine,dichlorvos, chlorothalonil, quinomethionate, cyhexatin, methomyl and benomyl)and chrysan<strong>the</strong>mum extracts (known to induce contact dermatitis due to <strong>the</strong>irsesquiterpene lactones) were studied in 59 male and 48 female chrysan<strong>the</strong>mumgrowers following <strong>the</strong> spring harvest season. The average age <strong>of</strong> males was38.6+11.8 years and <strong>the</strong> average age <strong>of</strong> females was 42.2+9.6 years. Subjects hadworked in flower growing <strong>for</strong> an average <strong>of</strong> 14 years and had reportedly beenexposed to a range <strong>of</strong> pesticides. Health in<strong>for</strong>mation was obtained usingquestionaires (work-related allergies, family history <strong>of</strong> allergies and general healthin<strong>for</strong>mation). Patch testing <strong>of</strong> <strong>the</strong> 7 pesticides and extracts was per<strong>for</strong>med on <strong>the</strong>inner side <strong>of</strong> <strong>the</strong> <strong>for</strong>earm and reactions read after 2 days. Subjects were alsoanalysed <strong>for</strong> serum immunoglobulins (IgE, IgA, IgG and IgM).―Approximately 60% <strong>of</strong> subjects were reported to have one or more work-relatedallergic symptoms (immediate-type or delayed-type), 25% had a personal history<strong>of</strong> allergic diseases and 26% a family history <strong>of</strong> allergic disease. Of <strong>the</strong> 27% <strong>of</strong>subjects who reported experiencing work-related skin conditions, approximatelyhalf attributed this to pesticides. Pesticides thought to be causative factorsincluded dichlorvos, chlorothalonil, methomyl, maneb and macozeb. Twentypercent <strong>of</strong> males and 44% <strong>of</strong> females patch-tested positive to at least one or more<strong>of</strong> <strong>the</strong> compounds. When subjects were patched tested with 0.02% dichlorvos,10% <strong>of</strong> males (6/59) and 19% <strong>of</strong> females (9/48) exhibited a positive reaction(average <strong>of</strong> 14%). On this basis, dichlorvos is concluded to be a skin sensitiser inhumans.‖ (Originals not sighted; APVMA, 2008a)The ATSDR (1997) reported:“A 52-year-old male truck driver who had been hauling pesticide containerspresented with dermatitis <strong>of</strong> his neck, anterior chest, dorsal hands, and<strong>for</strong>earms (Mathias 1983). On <strong>the</strong> previous day, several containers spilled inhis truck, and he apparently had direct dermal contact with a pesticidecontaining 5% dichlorvos, 15% petroleum distillates, and 80%trichloroethane. A faint papular dermatitis was present over <strong>the</strong> dorsal arms,hands, and V <strong>of</strong> <strong>the</strong> neck. .Vertical ery<strong>the</strong>matous, slightly scaling streaks werepresent over <strong>the</strong> lateral and posterior neck, a pattern suggesting that liquiddroplets had produced <strong>the</strong> dermatitis. The dermatitis was treated with 1%hydrocortisone ointment. Follow-up examination six weeks later showedDichlorvos reassessment – application Page 185 <strong>of</strong> 436
persistent vertical, mildly ery<strong>the</strong>matous streaks over <strong>the</strong> posterior andlateral neck; <strong>the</strong> arms and anterior chest had cleared. Negative patch testresults suggested that <strong>the</strong> dermatitis resulted from a primary irritant effect <strong>of</strong>dichlorvos on <strong>the</strong> skin. Dermatitis resolved completely approximately 10weeks after onset. The persistence <strong>of</strong> dermatitis 2 months after exposure isvery unusual, and <strong>the</strong> author suggested that this may be related to someunique local toxic effect <strong>of</strong> dichlorvos, but did not speculate fur<strong>the</strong>r.“In a guinea pig maximization test conducted in this study, induction withdichlorvos by intradermal injection and topical application and subsequentchallenge with topical dichlorvos solutions showed sensitization, <strong>the</strong>threshold irritation concentration <strong>of</strong> dichlorvos on guinea pig skin wasreported to be 1% (Ueda et al., 1994). Cross-reactivity with dichlorvos wasdemonstrated in animals induced with tri<strong>for</strong>ine.” (Originals not sighted;ATSDR, 1997)WHO (1988) reported:―In order to study <strong>the</strong> allergenicity <strong>of</strong> dichlorvos, <strong>the</strong> guinea-pig maximizationtest was used. Threshold limit values <strong>of</strong> primary irritancy tested on <strong>the</strong> skin <strong>of</strong>guinea-pigs (Hartley strain) were 2% or more. In <strong>the</strong> maximization test, 0.05 and0.5% were used. With 0.5%, 35% <strong>of</strong> <strong>the</strong> animals showed slight or discreteery<strong>the</strong>ma. The allergenicity rating as determined by <strong>the</strong> Kligman test wasmoderate. In combination with methidathion, dichlorvos showed a strongerreaction, indicating cross-sensitization (Fujita, 1985).‖ (Originals not sighted;WHO, 1988)Dichlorvos reassessment – application Page 186 <strong>of</strong> 436
12 MUTAGENICITY 6.6HSNO Classification: Mutagenicity – 6.6BKEY STUDY: NoneAs <strong>the</strong> classification <strong>for</strong> mutagenicity is based on <strong>the</strong> total weight <strong>of</strong> evidence available,<strong>the</strong>re is no single key study.The minimum degrees <strong>of</strong> hazard criteria <strong>for</strong> mutagenicity lists a hierachy <strong>of</strong> evidence(study types): mutagenic effects as a result <strong>of</strong> mammalian in vivo exposure; genotoxiceffects as a result <strong>of</strong> mammalian in vivo exposure, with mutagenic effects as a result <strong>of</strong>in vitro exposure; and, mutagenic effects as a result <strong>of</strong> in vitro exposure <strong>of</strong> mammaliancells, and <strong>the</strong> substance has a structure-activity relationship to known germ cellmutagens.Justification <strong>for</strong> Classification:Weight <strong>of</strong> evidence: There is an extensive genotoxicity database <strong>for</strong> dichlorvos.Negative results were reported in in vivo host-mediated, dominant lethal, sisterchromatid exchange and micronucleus assays (except on skin after local application atcytotoxic doses). Dichlorvos was reported not to induce in vivo chromosomalaberrations in bone-marrow cells, spermatocytes or spermatogonia, DNA strand breaksor unscheduled DNA syn<strong>the</strong>sis. The negative in vivo genotoxicity results wereexplained by <strong>the</strong> rapid metabolism and inactivation <strong>of</strong> dichlorvos, which appears toprevent systemic exposure to intact dichlorvos at concentrations likely to lead to directmolecular interactions.However, dichlorvos has genotoxic potential at localised high concentrations and in <strong>the</strong>absence <strong>of</strong> metabolism, demonstrated by micronucleus <strong>for</strong>mation in mouse epidermalkeratinocytes after direct application <strong>of</strong> dichlorvos to <strong>the</strong> skin; an increase in <strong>the</strong>mutation frequency in <strong>the</strong> liver <strong>of</strong> transgenic mice following repeated intraperitonealinjection; and, an increased incidence <strong>of</strong> hair follicle nuclear aberrations (NA) in CD1mice after a single application at 1/8 th <strong>the</strong> dermal LD 50 .Dichlorvos was mutagenic and DNA-reactive in bacteria and o<strong>the</strong>r microorganisms invitro, in both <strong>the</strong> presence and absence <strong>of</strong> exogenous metabolic activation (althougheffects were commonly reduced in <strong>the</strong> presence <strong>of</strong> exogenous metabolic activation).Dichlorvos was also mutagenic and clastogenic in a range <strong>of</strong> mammalian cells exposedin vitro, including induction <strong>of</strong> UDS but not chromosomal aberrations or SCE incultured human cells.Dichlorvos is an electrophile and stated to possess a structural alert <strong>for</strong>methylating activity. While dichlorvos possesses methylating activity, <strong>the</strong>phosphorous atom <strong>of</strong> <strong>the</strong> molecule is reported to be a stronger electrophile than<strong>the</strong> methyl carbon atoms (phosphorylating reactivity). In tissues and blood,dichlorvos is much more likely to react with “A”-type esterases, serumcholinesterase, or acetylcholinesterase than with DNA (ATSDR, 1997; APVMA,2008a).Dichlorvos reassessment – application Page 187 <strong>of</strong> 436
In summary, dichlorvos is mutagenic and clastogenic at <strong>the</strong> point <strong>of</strong> contact, whereunchanged dichlorvos may be in direct contact with tissue [DDVP‘s inherent potential].There is no evidence that dichlorvos has any systemic genotoxic potential, due to <strong>the</strong>substance‘s inherent phosphorylating reactivity and <strong>the</strong> highly efficientbiotrans<strong>for</strong>mation [low risk]. Dichlorvos should be Classified as 6.6B, as <strong>the</strong> evidencemeets <strong>the</strong> criteria in Section 14.2.2 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholds andClassifications in <strong>the</strong> HSNO Act (ERMA, 2008). However, <strong>the</strong> lack <strong>of</strong> systemicgenotoxic potential should be accounted <strong>for</strong> in any human risk assessment.Dichlorvos is proposed <strong>for</strong> classification <strong>for</strong> Carcinogenicity (6.7B), based on <strong>the</strong> dataavailable <strong>for</strong> this review (see Section 13 Carcinogenicity 6.7 below).The 6.6B Classification <strong>for</strong> mutagenicity is consistent with conclusions from reviews by<strong>the</strong> APVMA and ASTDR.BACKGROUND:The APVMA (2008a) reported <strong>the</strong> following in vivo and in vitro assays (Originals notsighted):Dichlorvos reassessment – application Page 188 <strong>of</strong> 436
ERMA New Zealand CONFIDENTIAL Report ID: dichlorvos_RA_ClassJune 2009 Dichlorvos Re-assessment – Review <strong>of</strong> Tox. & Classes 6 & 8 Page 189 <strong>of</strong> 436
The APVMA (2008a) summarised:―Numerous in vitro and in vivo experiments have tested <strong>the</strong> genotoxic potential <strong>of</strong>dichlorvos, with <strong>the</strong> majority <strong>of</strong> data generated between 1972 and 1990 andpublished in <strong>the</strong> open scientific literature. In <strong>the</strong> current submission, sevenunpublished genotoxicity studies were evaluated, which showed that dichlorvoswas genotoxic in vitro but not in vivo. These findings are consistent with <strong>the</strong>extensive genotoxicity database <strong>for</strong> dichlorvos.―Dichlorvos is mutagenic and DNA-reactive in bacteria and o<strong>the</strong>r microorganismsin vitro, in both <strong>the</strong> presence and absence <strong>of</strong> exogenous metabolic activation(although effects were commonly reduced in <strong>the</strong> presence <strong>of</strong> exogenous metabolicactivation). Dichlorvos is also mutagenic and clastogenic in a range <strong>of</strong>mammalian cells exposed in vitro, including induction <strong>of</strong> UDS but notchromosomal aberrations or SCE in cultured human cells. In contrast, <strong>the</strong> majority<strong>of</strong> in vivo studies, including tests <strong>for</strong> induction <strong>of</strong> UDS, SCE, micronucleus<strong>for</strong>mation, chromosomal aberrations and dominant lethal mutations, have yieldednegative results. These negative in vivo genotoxicity results can be explained by<strong>the</strong> rapid metabolism and inactivation <strong>of</strong> dichlorvos, which appears to preventsystemic exposure to intact dichlorvos at concentrations likely to lead to directmolecular interactions.―Tungul et al. (1991) described micronucleus <strong>for</strong>mation in mouse epidermalkeratinocytes after direct application <strong>of</strong> dichlorvos to <strong>the</strong> skin, confirming thatdichlorvos has genotoxic potential at localised high concentrations and in <strong>the</strong>absence <strong>of</strong> metabolism. Pletsa (1999) reported a 3-fold increase in <strong>the</strong> mutationfrequency in <strong>the</strong> liver <strong>of</strong> transgenic mice following repeated intraperitonealinjection <strong>of</strong> dichlorvos. In this same study, a single injection failed to have aneffect, while nei<strong>the</strong>r single nor repeated administration generated methylatedDNA adducts or increased <strong>the</strong> frequency <strong>of</strong> mutations in o<strong>the</strong>r tissues. Thesefindings are consistent with increased tumours (mostly papillomas) observed in<strong>the</strong> <strong>for</strong>estomach <strong>of</strong> mice, where tissue was exposed to high concentrations <strong>of</strong>unchanged dichlorvos (NCI 1977; Chan 1989).―The extensive genotoxicity database indicates that in <strong>the</strong> absence <strong>of</strong> metabolism,dichlorvos is mutagenic and clastogenic at <strong>the</strong> point <strong>of</strong> contact, where unchangeddichlorvos may be in direct contact with tissue. There is no evidence thatdichlorvos has any systemic genotoxic potential. Scenarios <strong>of</strong> prolonged exposurein <strong>the</strong> absence <strong>of</strong> metabolic activity are unlikely in <strong>the</strong> general population given<strong>the</strong> current patterns <strong>of</strong> use. Chronic inhalational exposure (<strong>the</strong> most likelyexposure route in humans) failed to cause tumours (Blair et al., 1974) or tomethylate nucleic acids in rats (Wooder et al., 1976). The failure <strong>of</strong> dichlorvos tomethylate DNA or RNA in vivo has been attributed to its phosphorylatingreactivity, leading to highly efficient biotrans<strong>for</strong>mation (Wright et al., 1979).Fur<strong>the</strong>rmore, <strong>the</strong> consistently negative in vivo genotoxicity findings consequentwith rapid metabolism indicate that dichlorvos is unlikely to pose a genotoxic riskto humans.‖ (Originals not sighted; APVMA, 2008a)Dichlorvos reassessment – application Page 190 <strong>of</strong> 436
The ATSDR (1997) reported:“Dichlorvos is an electrophile and possesses a structural alert <strong>for</strong> methylatingactivity. Dichlorvos has been tested <strong>for</strong> genotoxicity in a number <strong>of</strong> in vivoand in vitro systems. In general, dichlorvos was not genotoxic in in vivostudies but was generally genotoxic or mutagenic in in vitro tests whenmetabolizing enzymes (S9 fraction) were not present.“In <strong>the</strong> sex-linked lethal mutation test in Drosophila melanogaster,dichlorvos gave negative results when <strong>the</strong> flies were exposed by inhalation(Jayasuriya et al., 1973; Sobels and Todd 1979). Multiple generations <strong>of</strong> fliesexposed to food containing dichlorvos <strong>for</strong> 18 months had increasedmutations (Hanna and Dyer 1975). Salivary gland chromosome abnormalitieswere reported in larvae fed 1 ppm dichlorvos in food in one study (Gupta andSingh 1974), while ano<strong>the</strong>r study at lower levels showed no effect (Kramersand Knaap 1978).“No dominant lethal mutations were reported in ICR mice given a singleintraperitoneal dose or consecutive daily doses <strong>of</strong> 5 or 10 mg/kg [b.w.] orally(Epstein et al., 1972). In a similar study where dichlorvos was administeredby inhalation (30 or 55 mg/m 3 (3.3 or 6.1 ppm) to CF-1 mice, no dominantlethal mutations were observed (Dean and Thorpe 1972).“Male Q strain mice which received drinking water containing 2 mg/Ldichlorvos <strong>for</strong> 7 weeks did not show chromosome damage in bone marrowcells, spermatogonia, or primary spermatocytes (Moutschen-Dahmen et al.,1981). In a micronucleus test, Swiss mice given daily intraperitonealinjections <strong>of</strong> dichlorvos (0.0075 or 0.015 mg/kg [b.w.]) <strong>for</strong> 2 days showed noaberrations in structure or number <strong>of</strong> chromosomes in bone marrow cells.CF-1 mice exposed to 64-72 mg/m3 <strong>for</strong> 16 hours or to 5 mg/m3 <strong>for</strong> 21 daysdid not show chromosome abnormalities (Dean and Thorpe 1972). In Syrianhamsters, however, intraperitoneal injections at 3, 6, 15, and 30 mg/kg [b.w.]did cause increases in <strong>the</strong> number <strong>of</strong> cells with aberrant chromosomes(Dzwonkowska and Hubner 1986).“Dichlorvos was positive <strong>for</strong> binding to calf thymus DNA in vitro (L<strong>of</strong>roth1970; Segerbeck 1981). Dichlorvos was negative <strong>for</strong> DNA binding in vivo inrats (Wooder et al., 1977) and in mice (Segerbeck 1981).“In mutagenicity tests with S. typhimurium tester strains, dichlorvos hasgenerally been positive without metabolic activation and negative in <strong>the</strong>presence <strong>of</strong> S9. Dichlorvos in <strong>the</strong> presence <strong>of</strong> metabolic activation wasnegative in strains TA 98 (Braun et al., 1982), TA 1535 (Braun et al., 1982;Carere et al., 1976; Moriya et al., 1978) and TA 1536, 1537, and 1538 (Braunet al., 1982; Carere et al., 1976). Without metabolic activation, dichlorvos waspositive in strain TA 100 (Moriya et al., 1978), strain 1530 (Hanna and Dyer1975), strain 1535 (Carere et al., 1978; Hanna and Dyer 1975; Moriya et al.,1978; Shirasu et al., 1976), but negative in strains 1536, 1537, and 1538(Moriya et al., 1983; Shirasu et al., 1976).Dichlorvos reassessment – application Page 191 <strong>of</strong> 436
“The lack <strong>of</strong> dichlorvos genotoxicity in in vivo studies is most likely due to <strong>the</strong>fact that while dichlorvos possesses methylating activity, <strong>the</strong> phosphorousatom <strong>of</strong> <strong>the</strong> molecule is a stronger electrophile than <strong>the</strong> methyl carbon atoms(Wright et al. 1979). In tissues and blood, dichlorvos is much more likely toreact with “A”-type esterases, serum cholinesterase, or acetylcholinesterasethan with DNA (WHO 1989).” (Originals not sighted; ATSDR, 1997)WHO (1993) reported:―Mice were given i.p. injections <strong>of</strong> methyl- 14 C-dichlorvos (1.9 µmol/kg bw,approximately 420 µg/kg bw). The degree <strong>of</strong> alkylation <strong>of</strong> guanine-N-7 in DNAisolated from s<strong>of</strong>t tissues amounted to 8 x 10 -13 mol methyl per gram <strong>of</strong> DNA(about 5 x 10 -10 mol/mol guanine) (Segerback, 1981; Segerback & Ehrenberg,1981). From acute toxicity data in mouse it can be extrapolated that this dosewould cause 1 mol/mol phosphorylation <strong>of</strong> erythrocyte ChE.―DNA and RNA from <strong>the</strong> total s<strong>of</strong>t tissues <strong>of</strong> male rats exposed to atmospherescontaining 0.064 mg/m 3 (about 0.1% <strong>of</strong> <strong>the</strong> LC 50 ) <strong>of</strong> methyl- 14 C-dichlorvos <strong>for</strong> 12hours did not show methylation <strong>of</strong> <strong>the</strong> N-7 atom <strong>of</strong> guanine moieties. Theexposure period constituted a significant fraction <strong>of</strong> <strong>the</strong> half-life <strong>of</strong> <strong>the</strong> 7-methylguanine moieties in DNA (Wooder et al., 1977; Wooder & Wright, 1981).―Excretion <strong>of</strong> labelled 7-methylguanine in <strong>the</strong> urine by NMRI mice and ratsinjected i.p. with [Me- 14 C]-dichlorvos, or exposed by inhalation <strong>for</strong> 2 hours (miceonly) was reported by Wennerberg & L<strong>of</strong>roth (1974) and L<strong>of</strong>roth & Wennerberg(1974). In rat urine, labelled 3-methyladenine and 1-methyl-nicotinamide werealso present (L<strong>of</strong>roth & Wennerberg, 1974). According to <strong>the</strong> authors, <strong>the</strong>seresults demonstrate that dichlorvos spontaneously methylates guanine and adeninemoieties in nucleic acids. However, administration <strong>of</strong> radiolabelled adenine andguanine to o<strong>the</strong>rwise untreated rats gave rise to <strong>the</strong> excretion <strong>of</strong> radiolabelledmethylated purines in <strong>the</strong> urine. There<strong>for</strong>e, <strong>the</strong> detection <strong>of</strong> radiolabelled purines,per se, in <strong>the</strong> urine <strong>of</strong> animals exposed to methyl-labelled methylating agents doesnot constitute evidence <strong>for</strong> <strong>the</strong> spontaneous methylation <strong>of</strong> <strong>the</strong> purine moieties <strong>of</strong>nucleosides or nucleic acids by methylating agents (Wooder et al., 1978; Wooder& Wright, 1981). Moreover, a natural biosyn<strong>the</strong>tic pathway has beendemonstrated whereby <strong>the</strong> methyl carbon atoms <strong>of</strong> dichlorvos can be incorporatedinto <strong>the</strong> heterocyclic rings and <strong>the</strong> methyl groups <strong>of</strong> urinary 7-methylguanine afterentering <strong>the</strong> 1-C pools, in vivo (Wright et al., 1979; Wooder & Wright, 1981).‖(Originals not sighted; WHO, 1993)―In Drosophila melanogaster, chromosomal aberrations but not sex-linkedrecessive lethal mutations were induced. Negative results were obtained in hostmediated,dominant lethal, sister chromatid exchange and micronucleus assays(except on skin after local application at cytotoxic doses). Dichlorvos did notinduce in vivo chromosomal aberrations in bone-marrow cells, spermatocytes orspermatogonia, DNA strand breaks or unscheduled DNA syn<strong>the</strong>sis.‖ (Originalsnot sighted; WHO, 1993)The genotoxicity database available <strong>for</strong> dichlorvos was also summarised by:Dichlorvos reassessment – application Page 192 <strong>of</strong> 436
•ATSDR (1997): http://www.atsdr.cdc.gov/toxpr<strong>of</strong>iles/tp88.html•WHO (1993): http://www.inchem.org/documents/jmpr/jmpmono/v93pr05.htm•CCRIS (2008): http://toxnet.nlm.nih.gov/cgi-bin/sis/search - dichlorvosContact genotoxicity <strong>of</strong> dichlorvosA. Tungul, A.M. Bonin, S. He1 and R.S.U. Baker2Mutagenesis vol. 6 no. 5 pp. 405-408, 1991“Micronuclei induction by dichlorvos in <strong>the</strong> mouse skin”Toxicology Unit, National Institute <strong>of</strong> Occupational Health and Safety GPO Box 58,Sydney, New South Wales 2001, Australia 1 Guangxi Medical College Nanning,Guangxi, People's Republic <strong>of</strong> ChinaMicronucleus (MN) induction in cultured keratinocytes was investigated following skinpainting <strong>of</strong> HRA/Skh mice with <strong>the</strong> pesticide, dichlorvos. Whole skin and partiallypurifiedepidermal cells from 5–6 week old male animals were cultured <strong>for</strong> 4 days invitro after single topical applications <strong>of</strong> various concentrations <strong>of</strong> dichlorvos in vivo.Appropriate doses, allowing optimum survival <strong>of</strong> keratinocytes, were selected followingan initial range-finding experiment. To evaluate MN induction in dividing cells, <strong>the</strong>cytokinesis-block method was employed. Results showed statistically significant MN atall dose levels in partially-purified epidermal cells and a positive trend with respect todose from 51 to 1033 nmol dichlorvos. A significant increase in MN was also detectablein cultured cells from whole skin, dissociated within as little as 1 h after application <strong>of</strong>dichlorvos. Although a number <strong>of</strong> technical difficulties are associated with <strong>the</strong> skinmicronucleus method, it has been used successfully in this laboratory to detect severalskin carcinogens <strong>of</strong> both high and low potency. Since dichlorvos is rapidly absorbedthrough <strong>the</strong> skin, and can induce MN in skin cells <strong>of</strong> treated mice, this compound may<strong>the</strong>re<strong>for</strong>e be considered to pose a contact hazard <strong>for</strong> exposed humans.Pletsa V, Steenwinkel MJ, van Delft JH, Baan RA, Kyrtopoulos SA.Cancer Lett. 1999 Nov 15;146(2):155-60―Induction <strong>of</strong> somatic mutations but not methylated DNA adducts in lambdalacZtransgenic mice by dichlorvos.‖Laboratory <strong>of</strong> Chemical Carcinogenesis, Institute <strong>of</strong> Biological Research andBiotechnology, National Hellenic Research Foundation, A<strong>the</strong>ns, Greece.In order to examine <strong>the</strong> in vivo genotoxic activity <strong>of</strong> dichlorvos, lambdalacZ transgenicmice (Muta Mouse) were treated i.p. with single (4.4 or 11 mg/kg [b.w.]) or multiple (5x 11 mg/kg [b.w.]) doses <strong>of</strong> this agent and sacrificed 4 h or 14 days post-treatment <strong>for</strong>DNA adduct measurement or mutant frequency analysis, respectively. Nei<strong>the</strong>rmethylated DNA adducts nor an increase in mutant frequency were detected in <strong>the</strong> bonemarrow, white blood cells, liver, spleen, lung, brain and sperm cells after <strong>the</strong> singledoses. However, following multiple dosing a statistically significant 3-fold increase inmutant frequency was observed in <strong>the</strong> liver, while a non-statistically significant increasewas observed in <strong>the</strong> bone marrow. In contrast, dimethylsulphate, a model methylatingagent, gave rise to detectable DNA adducts but no increase in mutant frequencyDichlorvos reassessment – application Page 193 <strong>of</strong> 436
following i.p. administration <strong>of</strong> single (30 mg/kg [b.w.]) or multiple (10 x 6 mg/kg[b.w.]) doses.Schop RN, Hardy MH, Goldberg MT.Fundam Appl Toxicol. 1990 Nov;15(4):666-75.―Comparison <strong>of</strong> <strong>the</strong> activity <strong>of</strong> topically applied pesticides and <strong>the</strong> herbicide 2,4-D intwo short-term in vivo assays <strong>of</strong> genotoxicity in <strong>the</strong> mouse.‖Department <strong>of</strong> Biomedical Sciences, University <strong>of</strong> Guelph, Ontario, Canada.Genotoxicity <strong>of</strong> eight topically applied compounds was determined using <strong>the</strong> bonemarrow micronucleus (MN) test and hair follicle nuclear aberration (NA) assay in CD1mice. Twenty-four hours after a single treatment, cyclophosphamide (CY), applied atdoses corresponding to 1/4, 1/8, 1/16, and 1/32 <strong>of</strong> <strong>the</strong> published dermal LD50, and N-methyl-N-nitrosourea (MNU), applied at 1/4, 1/8, and 1/16 <strong>of</strong> <strong>the</strong> published dermalLD50, were found to increase <strong>the</strong> incidence <strong>of</strong> NA in a dose-dependent manner. Thefrequency <strong>of</strong> MN was significantly increased only at <strong>the</strong> highest dose <strong>of</strong> CY. Using <strong>the</strong>same protocol, six pesticides applied in dimethyl sulfoxide (DMSO) at doses <strong>of</strong> 1/8,1/16, and 1/32 <strong>of</strong> <strong>the</strong> dermal LD50 were investigated. Aminocarb and chlordaneinduced a dose-dependent increase in <strong>the</strong> frequency <strong>of</strong> NA, while <strong>the</strong>re was an observedincrease in NA incidence at only <strong>the</strong> highest doses <strong>of</strong> dichlorvos (DDVP), 4,4'-DDT(DDT), and 2,4-dichlorophenoxyacetic acid (2,4-D). No effect was observed withfenitrothion on nuclear aberrations in hair follicles. Except <strong>for</strong> <strong>the</strong> highest dose <strong>of</strong>chlordane, none <strong>of</strong> <strong>the</strong> pesticides tested positive in <strong>the</strong> bone marrow micronucleus test.Serum cholinesterase levels were reduced to 70 +/- 4.7% <strong>of</strong> <strong>the</strong> DMSO control levelwith DDVP, 57 +/- 8.2% with aminocarb, and 60.3 +/- 4.8% with fenitrothion,indicating some systemic activity with <strong>the</strong>se topically applied agents. The data suggestthat aminocarb, chlordane, DDVP, DDT, and 2,4-D are genotoxic as determined by <strong>the</strong>NA assay and that this assay may be more useful in detecting topically appliedgenotoxic agents than <strong>the</strong> more <strong>of</strong>ten used bone marrow micronucleus test.[Note: <strong>the</strong> hair follicle nuclear aberration (NA) assay is not currently an acceptedguideline test.]Dichlorvos reassessment – application Page 194 <strong>of</strong> 436
13 CARCINOGENICITY 6.7HSNO Classification: Carcinogenicity – 6.7BKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test material:Rat combined (chronic toxicity and carcinogenicity);Rat;Fischer 344/N;50/sex/group;Dichlorvos (batch No. SDC 092179; 99% purity);• Dose levels: 0, 4 or 8 mg/kg b.w./day in corn oil, 5 days/week <strong>for</strong> 103weeks;• Endpoint:• Remarks:Clinical signs, mortality, body weight gain, foodconsumption, clinical chemistry, haematology or urinaryparameters, organ weight, gross/microscopic abnormalitiesand tumour incidences. Plasma and RBC ChE activitieswere measured in a separate experiment;Mild diarrhoea was reportedly treatment-related but <strong>the</strong>rewere no o<strong>the</strong>r adverse clinical signs. No treatment-relatedeffects on bodyweight gain or survival were reported.Cytoplasmic vacuolisation <strong>of</strong> <strong>the</strong> liver and adrenal cortexwas observed at increased frequency in low-dose (26%)and high-dose (38%) males compared to controls (14%).Adrenal cortical cytoplasmic vacuolisation was alsoobserved in high-dose males (26% compared to 6% incontrols) and low-dose females (34% compared to 9% incontrols).Non-neoplastic and neoplastic lesions <strong>of</strong> <strong>the</strong> pancreas wereobserved in both sexes. The incidence <strong>of</strong> acinarhyperplasia in treated groups <strong>of</strong> ei<strong>the</strong>r sex was notsignificantly different from <strong>the</strong> controls. When crosssectionaland horizontal sectional data were combined, <strong>the</strong>total incidence <strong>of</strong> adenomas was significantly higher(p
historical control range (0-28%). Corn oil gavage, itself, isstated to increase <strong>the</strong> incidence <strong>of</strong> acinar cell adenomas inmale rats [Note: NTP website - historical control range <strong>for</strong>pancreatic adenoma in males using corn oil gavage (n=8)as 2-24%; NIH 07 Rat & Mouse Ration].Horizontal sectionsNumbers <strong>of</strong> Male Rats with Pancreatic Lesions (Chan, 1989; NTP TR342)Vehicle Control 4 mg/kg b.w. 8 mg/kg b.w.Acinar cell hyperplasia 33 44 39Acinar cell adenoma (single) 12 13 7Acinar cell adenoma (multiple) 3 10 10Acinar cell adenoma (total) 15 23 17Cross-sections and horizontalsections (composite)Acinar cell hyperplasia 37 45 39Acinar cell adenoma (single) 16 8 13Acinar cell adenoma (multiple) 9 22* 20*Acinar cell adenoma (total) 25 (50%) a,b 30* (60%) 33* (66%)* P < 0.05 vs. vehicle controls by logistical regression test;a historical control range <strong>of</strong> adenomas in cross-section from 8 studies at <strong>the</strong> test facility was 0-22%;bhistorical control range <strong>of</strong> adenomas in cross-section from 34 NTP studies using corn oil gavage was 0-28%The incidence <strong>of</strong> mononuclear cell leukaemia (MCL) inmales was significantly increased [11/50 (22%), 20/50(40%), 21/50 (42%) in control, low dose and high dosegroups, respectively]. The incidence <strong>of</strong> MCL in males in<strong>the</strong> present study was within <strong>the</strong> NTP and facility historicalcontrol ranges (respectively: 2-44%, n= 34 [NTP studies];2-18%, n=8 [facility studies]). The incidence <strong>of</strong> MCL infemales was 17/50 (34%) in <strong>the</strong> controls, 21/50 (42%) at<strong>the</strong> low dose and 23/50 (46%) at <strong>the</strong> high-dose [<strong>the</strong>APVMA noted that <strong>the</strong>re was no suitable historical controldata to put <strong>the</strong>se data in context][Note: NTP website -historical control range <strong>for</strong> Leukemia: Lymphocytic,Monocytic, Mononuclear, or Undifferentiated in malesusing corn oil gavage (from 8 separate control groups) as16-44%; in females (from 8 separate control groups) 12-34%; NIH 07 Rat & Mouse Ration].Alveolar/bronchiolar adenomas were observed in 3/50(6%) high dose-males but in no o<strong>the</strong>r group. Thisincidence was within <strong>the</strong> historical control range <strong>of</strong> 0-8%.The incidence <strong>of</strong> mammary gland fibroadenomas infemales was significantly but not dose dependentlyincreased; 9/50 (18%) in controls, 19/50 (38%) in lowdoseand 16/50 (32%) in high-dose groups. MultipleDichlorvos reassessment – application Page 196 <strong>of</strong> 436
fibroadenomas were observed in 6 (12%) <strong>of</strong> <strong>the</strong> low doseand 3 (6%) <strong>of</strong> <strong>the</strong> high-dose females, and one adenoma(2%) was observed in a high-dose female. Two mammarygland carcinomas were observed in each <strong>of</strong> <strong>the</strong> control andlow-dose groups (4%). The incidence <strong>of</strong> mammarytumours in <strong>the</strong> present study was within <strong>the</strong> NTP or facilityhistorical control range [<strong>the</strong> APVMA reportedrespectively: 12-40%; 16-18%, and concluded <strong>the</strong>re<strong>for</strong>enot biologically significant] [Note: NTP website -historical control range <strong>for</strong> Mammary Gland: Fibroma,Fibroadenoma, Carcinoma, or Adenoma in females usingcorn oil gavage (from 8 separate control groups) as 28-48%; NIH 07 Rat & Mouse Ration].Fibroadenomas (a)Mammary Gland Tumours in Female Rats (Chan, 1989; NTP TR342)Vehicle Control 4 mg/kg b.w. 8 mg/kg b.w.Overall Rates 9/50 (18%) 19/50 (38%) 16/50 (32%)Adjusted Rates (c) 24.5% 62.4% 45.6%Terminal Rates 6/31 (19%) 15/26 (58%) 8/26 (31%)Day <strong>of</strong> First Observation 547 545 582AdenomaOverall Rates 0/50 (0%) 0/50 (0%) 1/50 (2%)CarcinomaOverall Rates 2/50 (4%) 2/50 (4%) 0/50 (0%)Fibroadenomas, Adenoma, or Carcinoma (b)Overall Rates 11/50 (22%) 20/50 (40%) 17/50 (34%)Adjusted Rates (c) 28.2% 65.8% 48.6%Terminal Rates 6/31 (19%) 16/26 (62%) 9/26 (35%)Day <strong>of</strong> First Observation 547 545 582Life Table Tests P = 0.049 P = 0.015 P = 0.074Logistical Regression Tests P = 0.072 P = 0.028 P = 0.113(a) Includes multiple fibroadenomas; historical incidence, facility: 113/400 (21-35%); NTP: 436/1700 (19-33%);(b) Historical incidence <strong>of</strong> benign or malignant mammary gland neoplasms (all types combined), facility:124/400 (23-39%); NTP: 474/1700 (20-36%)(c) Kaplan-Meier estimated tumour incidences at <strong>the</strong> end <strong>of</strong> <strong>the</strong> study after adjusting <strong>for</strong> intercurrent mortality.Dichlorvos reassessment – application Page 197 <strong>of</strong> 436
(APVMA, 2008a)• NOAEL < 4 mg/kg b.w./day (lowest dose tested), as plasma ChE was inhibitedin all test groups.The NTP Peer Review concluded that: ―Under <strong>the</strong> conditions <strong>of</strong> <strong>the</strong>se 2-yeargavage studies, <strong>the</strong>re was some evidence <strong>of</strong> carcinogenic activity <strong>of</strong> dichlorvos<strong>for</strong> male F344/N rats, as shown by increased incidences <strong>of</strong> adenomas <strong>of</strong> <strong>the</strong>exocrine pancreas and mononuclear cell leukemia. There was equivocalevidence <strong>of</strong> carcinogenic activity <strong>of</strong> dichlorvos <strong>for</strong> female F344/N rats, asshown by increased incidences <strong>of</strong> adenomas <strong>of</strong> <strong>the</strong> exocrine pancreas andmammary gland fibroadenomas.‖ (Chan PC, 1989)The APVMA review concluded that: ―There was a significant increase inexocrine proliferative lesions <strong>of</strong> <strong>the</strong> pancreas in males at 4 and 8 mg/kgbw/d[ay], which were considered to show an equivocal relationship withtreatment. The increased incidences <strong>of</strong> MCL in males and mammary tumoursin females were not considered biologically significant due to <strong>the</strong> lack <strong>of</strong> adose-response relationship and as <strong>the</strong> incidences fell within <strong>the</strong> NTP‘srespective historical control range.‖ (APVMA, 2008a)• GLP:• Test Guideline:US FDA;No in<strong>for</strong>mation;• Reference source: Chan PC (1989) ―Toxicology and carcinogenesis studies <strong>of</strong>dichlorvos (CAS No. 62-73-7) in F344/N rats and B6C3F1mice (gavage studies).‖ Per<strong>for</strong>med at Sou<strong>the</strong>rn ResearchInstitute <strong>for</strong> <strong>the</strong> National Toxicology Program, ResearchTriangle Park. Technical Report Series NTP TR No.342.;• Reliability:Klimisch score 2 = reliable with restrictions;KEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:Mouse oncogenicity study;Mouse;B6C3F1;Dichlorvos reassessment – application Page 198 <strong>of</strong> 436
• Sex/Numbers:• Test material:• Dose levels:• Endpoint:• Remarks:50/sex/group;Dichlorvos (batch No. SDC 092179; 99% purity);0, 10 or 20 mg/kg bw/day (males) or 0, 20 or 40 mg/kgb.w./day (females) in corn oil, 5 days/week <strong>for</strong> 103 weeks;Clinical signs, mortality, body weight gain, foodconsumption, clinical chemistry, haematology or urinaryparameters, organ weight, gross/microscopic abnormalitiesand tumour incidences. Plasma and RBC ChE activitieswere measured in a separate experiment;Bodyweight gain was similar in all groups. Survival wasunaffected by treatment.Non-neoplastic lesions occurred with similar frequency inall groups and no effects <strong>of</strong> treatment on incidences wereobserved.The incidence <strong>of</strong> <strong>for</strong>estomach squamous cell papillomaswas elevated at <strong>the</strong> highest dose in both sexes. This wasstatistically significant on trend analysis in both sexes, butonly in females using a pair-wise comparison between <strong>the</strong>high dose and control groups. These incidence rates wereoutside <strong>the</strong> available historical control ranges [Note: NTPwebsite - historical control range <strong>for</strong> Stomach,Forestomach: Squamous Cell Papilloma in males usingcorn oil gavage (from 8 separate control groups) as 0-2%;in females, 0-2%; <strong>for</strong> Stomach, Forestomach: SquamousCell Carcinoma in females using corn oil gavage (from 8separate control groups) as 0%; NIH 07 Rat & MouseRation]. Forestomach carcinomas were evident in 2females (4%) at 40 mg/kg bw/d but not in any o<strong>the</strong>r group,again outside <strong>the</strong> available historical control range.MaleHyperplasiaForestomach Squamous Lesions in Mice (Chan, 1989; NTP TR342)VehicleControl10 mg/kg b.w. 20 mg/kg b.w. 40 mg/kg b.w.Overall Rates 11/50 (22%) 5/50 (10%) 9/50 (18%)Papilloma (a)Overall Rates 1/50 (2%) 1/50 (2%) 5/50 (10%)Adjusted Rates (c) 2.9% 3.2% 17.2%Terminal Rates 1/35 (3%) 0/27 (0%) 5/29 (17%)Day <strong>of</strong> First Observation 729 714 729Life Table Tests P = 0.033 P = 0718 P = 0.064Dichlorvos reassessment – application Page 199 <strong>of</strong> 436
FemaleLogisitic Regression Tests P = 0.032 P = 0753 P = 0.067HyperplasiaOverall Rates 6/49 (12%) 7/49 (14%) 5/50 (10%)PapillomaOverall Rates 5/49 (10%) 6/49 (12%) 18/50 (36%)Adjusted Rates (c) 17.4% 18.1% 44.9%Terminal Rates 3/26 (12%) 4/29 (14%) 13/34 (38%)Day <strong>of</strong> First Observation 669 442 520Life Table Tests P = 0.006 P = 0.556 P = 0.016Logisitic Regression Tests P = 0.002 P = 0.505 P = 0.004CarcinomaOverall Rates 0/49 (0%) 0/49 (0%) 0/50 (0%)Papilloma or Carcinoma (b)Overall Rates 5/49 (10%) 6/49 (12%) 19/50 (38%)Adjusted Rates (c) 17.4% 18.1% 47.5%Terminal Rates 3/26 (12%) 4/29 (14%) 14/34 (41%)Day <strong>of</strong> First Observation 669 442 520Life Table Tests P = 0.006 P = 0.556 P = 0.011Logisitic Regression Tests P = 0.002 P = 0.505 P = 0.003(a) Historical incidence <strong>of</strong> papillomas or carcinomas (combined), facility: 4/396 (0-4%); NTP: 23/1703 (0-3%);(b) Historical incidence <strong>of</strong> papillomas, facility: 4/396 (0-3%); NTP: 16/1703 (0-3%). No squamous cell carcinomashad been observed in corn oil vehicle control female B6C3F1 mice in NTP studies.(c) Kaplan-Meier estimated tumour incidences at <strong>the</strong> end <strong>of</strong> <strong>the</strong> study after adjusting <strong>for</strong> intercurrent mortality.(APVMA, 2008a)• NOAEL =• LOAEL =10 mg/kg b.w./day <strong>for</strong> males and 20 mg/kg b.w./day <strong>for</strong>females;20 mg/kg b.w./day <strong>for</strong> males and 40 mg/kg b.w./day <strong>for</strong>females, based on <strong>for</strong>estomach lesions (specificallypapillomas);Dichlorvos reassessment – application Page 200 <strong>of</strong> 436
The NTP Peer Review concluded that: ―There was some evidence <strong>of</strong> carcinogenicactivity <strong>of</strong> dichlorvos <strong>for</strong> male B6C3F1 mice, as shown by increased incidences <strong>of</strong><strong>for</strong>estomach squamous cell papillomas. There was clear evidence <strong>of</strong> carcinogenicactivity <strong>of</strong> dichlorvos <strong>for</strong> female B6C3F1 mice, as shown by increased incidences<strong>of</strong> <strong>for</strong>estomach squamous cell papillomas.‖ (Chan PC, 1989)The APVMA review concluded that: ―The occurrence <strong>of</strong> <strong>for</strong>estomach carcinomasin females at 40 mg/kg bw/d[ay] showed an equivocal relationship with treatment.Mechanistic studies … demonstrate that dichlorvos is irritating to <strong>the</strong> mouse GIT,as it is to rabbit eyes and skin. Given its irritancy and consistently negative resultsin in vivo genotoxicity studies, <strong>the</strong> increase in <strong>for</strong>estomach papillomas seen in thisstudy are concluded to be irrelevant to human dietary risk assessment.‖(APVMA, 2008a) [Note: There is some evidence <strong>for</strong> genotoxicity at site <strong>of</strong>exposure (skin studies) and this supports <strong>the</strong> possibility <strong>of</strong> genotoxicity having arole in <strong>the</strong> <strong>for</strong>estomach tumours in mice.]• GLP:• Test Guideline:US FDA;No in<strong>for</strong>mation;• Reference source: Chan PC (1989) ―Toxicology and carcinogenesis studies <strong>of</strong>dichlorvos (CAS No. 62-73-7) in F344/N rats and B6C3F1mice (gavage studies).‖ Per<strong>for</strong>med at Sou<strong>the</strong>rn ResearchInstitute <strong>for</strong> <strong>the</strong> National Toxicology Program, ResearchTriangle Park. Technical Report Series NTP TR No.342.;• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification:The Chan (1989) studies in rats and mice were carriedout to GLP and NTP guidelines. There is some evidence <strong>for</strong> carcinogenic activity inboth rats and mice, but at different target organs in each species and sex. Theincreased incidence <strong>of</strong> adenomas <strong>of</strong> <strong>the</strong> exocrine pancreas in male F344/N ratsindicated to <strong>the</strong> NTP some evidence <strong>of</strong> carcinogenic activity <strong>of</strong> dichlorvos, but wasconsidered equivocal by <strong>the</strong> APVMA, due in part to <strong>the</strong> lack <strong>of</strong> a statistical increaseor dose-response in <strong>the</strong> horizontal sections and issues with <strong>the</strong> control data (highincidence in concurrent controls; large historic control ranges; corn oil vehicleknown to induce tumour type). The 2-year inhalation study in CFE rats (Blair et al.,1974 & 1976), reviewed by <strong>the</strong> APVMA and ATSDR revealed no evidence <strong>of</strong>carcinogenicity. However, Chan (1989) also revealed increased incidences <strong>of</strong><strong>for</strong>estomach squamous cell papillomas in male and female B6C3F1 mice. While<strong>for</strong>estomach tumours are not considered directly relevant to humans and <strong>the</strong> APVMAhave suggested <strong>the</strong> tumours may be a response to <strong>the</strong> irritancy <strong>of</strong> dichlorvos, <strong>the</strong>sefindings (and <strong>the</strong> mutagenic potential in certain contact scenarios, see Section 12Mutagenicity) indicate that repeated exposure to high concentrations <strong>of</strong> dichlorvosposes some carcinogenic hazard. Dichlorvos should be classified as 6.7B, as <strong>the</strong>evidence meets <strong>the</strong> criteria in Section 15.2.2 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholds andClassifications in <strong>the</strong> HSNO Act (ERMA, 2008). However, TCL notes that <strong>the</strong>relevance <strong>of</strong> <strong>the</strong> exposure scenarios and tumours should be taken into account in anyhuman risk assessment.Dichlorvos reassessment – application Page 201 <strong>of</strong> 436
BACKGROUND:The ATSDR (1997) summarised <strong>the</strong> carcinogenic potential <strong>of</strong> DDVP thus:“In a 2-year carcinogenicity study <strong>of</strong> inhalation exposure to dichlorvos,groups <strong>of</strong> 50 Carworth rats <strong>of</strong> each sex were exposed at levels <strong>of</strong> 0, 0.05, 0.5,or 5 mg/m 3 (Blair et al. 1976). Only 11 <strong>of</strong> <strong>the</strong> unexposed male controls and25 <strong>of</strong> <strong>the</strong> unexposed female controls survived to <strong>the</strong> end <strong>of</strong> <strong>the</strong> study.Survival was actually highest in <strong>the</strong> rats receiving <strong>the</strong> highest dose <strong>of</strong>dichlorvos (32 <strong>of</strong> 50 males and 34 <strong>of</strong> 50 females). Microscopic examinationrevealed a wide range <strong>of</strong> lesions in all groups; <strong>the</strong> authors stated that <strong>the</strong>seare commonly seen in old rats <strong>of</strong> this strain. There was a high incidence in allgroups <strong>of</strong> chronic nephrosis, focal myocardial fibrosis, degenerative arterydisease, lymphoid hyperplasia <strong>of</strong> <strong>the</strong> spleen, and testicular atrophy. Commontumors in all groups were adenomas <strong>of</strong> <strong>the</strong> anterior pituitary gland,parafollicular cell adenomas, and carcinomas <strong>of</strong> <strong>the</strong> thyroid gland, adrenalpheochromocytomas, and mammary fibroadenomas in <strong>the</strong> females.Examination <strong>of</strong> <strong>the</strong> lungs (presumably <strong>the</strong> tissue receiving <strong>the</strong> highest dose)revealed minor changes in all groups. Peribronchial and perivascularlymphoid aggregates, mild degrees <strong>of</strong> bronchiolitis and focal alveolarthickening were noted. Electron microscopic examination <strong>of</strong> bronchi,bronchioli, and alveoli <strong>of</strong> a small number <strong>of</strong> control and high-dose groupanimals showed no differences between <strong>the</strong> groups. None <strong>of</strong> <strong>the</strong> lesions in <strong>the</strong>study was associated with dichlorvos exposure.“The high mortality <strong>of</strong> <strong>the</strong> control animals in this study makes interpretation<strong>of</strong> <strong>the</strong> carcinogenicity data problematic. The possibility also exists thatexposure by <strong>the</strong> oral and dermal routes may have occurred. However, nosignificant increase in neoplastic or non-neoplastic lesions was found in <strong>the</strong>nasal and respiratory tract tissues that received <strong>the</strong> highest dose <strong>of</strong>dichlorvos.“In a carcinogenicity study in Osborne-Mendel rats, groups <strong>of</strong> 50 animals <strong>of</strong>each sex were originally dosed through feed at levels <strong>of</strong> 45 and 90 mg/kg[b.w.]/day (NCI 1977). During <strong>the</strong> initial 3 weeks <strong>of</strong> dosage, acute signs <strong>of</strong>toxicity were observed including tremor and diarrhea in <strong>the</strong> 90 mg/kg[b.w.]/day group. For this reason, <strong>the</strong> dosages were <strong>the</strong>n lowered to 30% <strong>of</strong><strong>the</strong> original. The TWA doses over <strong>the</strong> 80-week period <strong>of</strong> dosing were 13.5and 29.3 mg/kg [b.w.]/day. After <strong>the</strong> 80-week dosing period, <strong>the</strong> animalswere observed <strong>for</strong> a fur<strong>the</strong>r 30 weeks until sacrifice. Adverse clinical signs(hematuria, rough coats, epistaxis) were noted in control and dosed animals,gradually increasing during <strong>the</strong> second year <strong>of</strong> <strong>the</strong> study. The authors statedthat at <strong>the</strong> end <strong>of</strong> <strong>the</strong> study <strong>the</strong> rats were in generally poor condition. Thematched control groups had significantly lower survival than <strong>the</strong> treatedgroups at <strong>the</strong> end <strong>of</strong> <strong>the</strong> study, mainly due to deaths during <strong>the</strong> 30-weekobservation period after treatment. At <strong>the</strong> termination <strong>of</strong> <strong>the</strong> study, only 2 <strong>of</strong>10 male rats and 5 <strong>of</strong> 10 female rats survived in <strong>the</strong> matched control groups.For this reason, <strong>the</strong>se control rats were pooled with control rats fromDichlorvos reassessment – application Page 202 <strong>of</strong> 436
concurrent studies <strong>for</strong> comparison with <strong>the</strong> treated groups. Of <strong>the</strong> male rats,76% <strong>of</strong> <strong>the</strong> high-dose and 64% <strong>of</strong> <strong>the</strong> low-dose group survived to <strong>the</strong> end <strong>of</strong><strong>the</strong> study as did 84% <strong>of</strong> <strong>the</strong> high-dose and 80% <strong>of</strong> <strong>the</strong> low-dose females.“Numerous inflammatory, degenerative, and proliferative lesions commonlyseen in aged rats occurred with approximately equal frequency in <strong>the</strong> treatedand <strong>the</strong> pooled control rats. Several non-neoplastic lesions occurred morefrequently in <strong>the</strong> treated rats than in <strong>the</strong> controls. These included aggregates<strong>of</strong> alveolar macrophages in <strong>the</strong> lungs, interstitial fibrosis <strong>of</strong> <strong>the</strong> myocardium,and focal follicular cell hyperplasia <strong>of</strong> <strong>the</strong> thyroid gland in <strong>the</strong> male rats.Benign endocrine neoplasms occurred frequently in both test and controlrats. There was a high incidence <strong>of</strong> benign mammary neoplasms in bothcontrol and treated rats. Because <strong>of</strong> <strong>the</strong> low survival <strong>of</strong> <strong>the</strong> matched controlrats, control animals from o<strong>the</strong>r concurrent studies were pooled <strong>for</strong>statistical analysis. The authors stated that on <strong>the</strong> basis <strong>of</strong> variability <strong>of</strong> both<strong>the</strong> incidence and type <strong>of</strong> spontaneous lesions and <strong>the</strong> lack <strong>of</strong> significantproportions <strong>of</strong> tumors in <strong>the</strong> dosed groups compared to <strong>the</strong> controls, nostatistical significance could be attached to <strong>the</strong> incidence <strong>of</strong> <strong>the</strong> tumors seenin <strong>the</strong> dichlorvos-treated rats in this study. Because <strong>of</strong> <strong>the</strong> poor survival <strong>of</strong>control animals in this study, <strong>the</strong> results are difficult to interpret.”“The mechanism <strong>of</strong> dichlorvos-induced carcinogenicity is not known. A study<strong>of</strong> B6C3F1 mouse <strong>for</strong>estomach from mice treated with dichlorvos by gavagein corn oil (Ben<strong>for</strong>d et al., 1994) showed increases in replicative DNAsyn<strong>the</strong>sis (associated with increased cell proliferation). Unscheduled DNAsyn<strong>the</strong>sis (associated with DNA repair) was not increased by dichlorvostreatment, but was increased by 1 -methyl-3-nitro-1 -nitrosoguanidine, aknown genotoxic <strong>for</strong>estomach carcinogen. The authors concluded that <strong>the</strong><strong>for</strong>estomach tumors seen in <strong>the</strong> 2-year carcinogenicity study (NTP 1989)may have been mediated by en<strong>for</strong>ced cellular proliferation ra<strong>the</strong>r than by agenotoxic mechanism.“Two organizations have reviewed <strong>the</strong> evidence <strong>for</strong> dichlorvoscarcinogenicity in humans from <strong>the</strong> results obtained in test systems. The EPAhas classified dichlorvos as a probable human carcinogen (Category B2) on<strong>the</strong> basis <strong>of</strong> significant increases <strong>of</strong> <strong>for</strong>estomach tumors in mice andleukemiasand pancreatic acinar adenomas in rats. Supporting evidenceincluded observation <strong>of</strong> tumors at o<strong>the</strong>r sites in <strong>the</strong> rat and <strong>the</strong> observationthat dichlorvos and a major metabolite, dichloroacetaldehyde, are mutagenicin in vitro test systems. A structurally related compound, dichloropropene,also causes <strong>for</strong>estomach tumors in rodents (IRIS 1995).” (Originals notesighted; ATSDR, 1997)The IARC (1991) summary and evaluation <strong>for</strong> dichlorvos:“5.1 Exposure data―Dichlorvos has been used widely as an insecticide since 1961 to control internaland external parasites in livestock and domestic animals, to control insects inhouses, and in crop protection.Dichlorvos reassessment – application Page 203 <strong>of</strong> 436
―Dichlorvos has been <strong>for</strong>mulated <strong>for</strong> use as dusts, granules, pellets/tablets,impregnated resin strips and concentrates.―Household and public health uses represent <strong>the</strong> main sources <strong>of</strong> human exposureto dichlorvos. Exposure may also occur during its production and application.“5.2 Carcinogenicity in humans―One case-control study <strong>of</strong> leukaemia in <strong>the</strong> USA found an association with use <strong>of</strong>dichlorvos on animals; <strong>the</strong>re were few exposed subjects, and <strong>the</strong>y had potentialexposure to many pesticides.“5.3 Carcinogenicity in experimental animals―Dichlorvos was tested <strong>for</strong> carcinogenicity by oral administration in twoexperiments in mice and in three experiments in rats. A few rare oesophagealsquamous-cell tumours were found in mice treated with dichlorvos in <strong>the</strong> diet. Adose-related increase in <strong>the</strong> incidence <strong>of</strong> squamous-cell tumours (mainlypapillomas) was noted in <strong>the</strong> <strong>for</strong>estomachs <strong>of</strong> mice that received dichlorvos incorn oil by gavage. In rats that received dichlorvos in water by gavage, a fewsquamous-cell papillomas <strong>of</strong> <strong>the</strong> <strong>for</strong>estomach were seen. In rats that receiveddichlorvos in corn oil by gavage, a dose-related increase in <strong>the</strong> incidence <strong>of</strong>mononuclear-cell leukaemia and an increased incidence <strong>of</strong> pancreatic acinar-celladenomas were observed in males.“5.4 O<strong>the</strong>r relevant data―A variety <strong>of</strong> studies in several species did not demonstrate developmentaltoxicity due to dichlorvos.“In vitro, dichlorvos phosphorylates esterases to a greater extent than itmethylates nucleophiles; <strong>the</strong> likelihood <strong>of</strong> DNA methylation in vivo is extremelysmall.―Immunosuppression has been noted after short-term administration <strong>of</strong> high doses<strong>of</strong> dichlorvos which are associated with pr<strong>of</strong>ound cholinergic hyperstimulation.―No data were available on <strong>the</strong> genetic and related effects <strong>of</strong> dichlorvos inhumans.―Dichlorvos was not shown to have genetic activity in various assays in mammalsin vivo. It induced gene mutation and chromosomal damage in culturedmammalian cells and in insects, plants, fungi, yeast and bacteria.“5.5 Evaluation―There is inadequate evidence in humans <strong>for</strong> <strong>the</strong> carcinogenicity <strong>of</strong> dichlorvos.―There is sufficient evidence in experimental animals <strong>for</strong> <strong>the</strong> carcinogenicity <strong>of</strong>dichlorvos.“Overall evaluation―Dichlorvos is possibly carcinogenic to humans (Group 2B).‖Dichlorvos reassessment – application Page 204 <strong>of</strong> 436
The APVMA (2008a) reported a chronic inhalation study in rats:―Blair D, Dix KM & Hunt PF (1974) Two year inhalation exposure <strong>of</strong> rats todichlorvos vapour. Report No. TLGR.0026.74. Lab: Tunstall Laboratory, ShellResearch Ltd, Sittingbourne Research Center, UK. Report date: June 1974.―Blair D, Dix KM, Hunt PF, Thorpe E, Stevenson DE & Walker AIT (1976)Dichlorvos - a 2-year inhalation carcinogenesis study in rats. Arch. Toxicol. 35:281-294.―Materials and Methods―Carworth Farm E (CFE) rats (50/sex/group) were exposed individually to airconcentrations <strong>of</strong> dichlorvos (SNC Pernis, unspecified location; batch No.unspecified; >97% purity) at 0, 0.05, 0.5 or 5 mg/m 3 <strong>for</strong> 23 h[our]/d[ay] <strong>for</strong> 2years. Achieved mean concentrations were 0, 0.05, 0.48 and 4.70 mg/m 3 ,respectively. Trimethyl phosphate was also present at 0, 0.007 and 0.04 mg/m 3 in<strong>the</strong> low-, mid- and high-dose atmospheres, respectively, as was DCA[dichloroacetaldehyde] at 0.007, 0.013 and 0.028 mg/m 3 . The method <strong>of</strong>application meant that <strong>the</strong> rats were exposed dermally, orally (via contamination<strong>of</strong> food and water, cage interior and grooming fur), as well as by inhalation.―Rats were housed individually in metal wire cages and fed ad libitum with Diet86 pellets (Charles River, UK). Body weights and feed intake were measuredmonthly and behaviour was monitored daily. Rats dying during <strong>the</strong> course <strong>of</strong> <strong>the</strong>study were necropsied where possible. Haematology (Hb, erythrocyte, totalleucocyte and differential leucocyte counts, prothrombin time, and kaolincephalincoagulation time) and clinical chemistry (protein, urea, Na, K, glucoseand Cl concentrations, and plasma AP, AST and ALT activities) were examinedin blood samples collected at necropsy. RBC and plasma ChE activities weremeasured at <strong>the</strong> same time.―Necropsies were per<strong>for</strong>med on all animals sacrificed at <strong>the</strong> end <strong>of</strong> <strong>the</strong> treatmentperiod. Major organs (brain, heart, liver, spleen and kidneys) were weighed and<strong>the</strong>se along with additional tissues (anterior pituitary, thyroid, adrenals, mammarygland, pancreas, skin, reticulo-endo<strong>the</strong>lial system, tongue, nasal cavity, trachea,skeletal muscle, and eye and lachrymal gland) were examined microscopically.The left half <strong>of</strong> each brain was used <strong>for</strong> examination <strong>of</strong> ChE activity. Additionalbrain samples were provided to an independent laboratory (B. Holmstedt,Karolinska Intitutet, Stockholm) <strong>for</strong> assessment <strong>of</strong> acetylcholine and cholineconcentrations.―Statistical analysis consisted <strong>of</strong> analysis <strong>of</strong> variance with Student t-test or χ2 test<strong>for</strong> comparison between treated and control groups.―ResultsDichlorvos reassessment – application Page 205 <strong>of</strong> 436
“Mortalities, Clinical Signs and Effects on Bodyweight and Food Consumption:The average weekly concentrations <strong>of</strong> dichlorvos in test atmospheres werereasonably consistent and close to nominal throughout <strong>the</strong> treatment period.Mortality was highest in control groups and lowest in high-dose groups. Survivalrates <strong>of</strong> 22, 42, 30 and 64% in males, and 50, 60, 58 and 76% in females recordedin control, low-, mid- and high-dose groups, respectively. The highest morbidityrate in controls occurred from approximately 75 weeks. The low survival incontrols caused <strong>the</strong> early cessation <strong>of</strong> treatment in males during week 99; femaletreatment continued to week 104.―There were no adverse clinical signs indicative <strong>of</strong> OP poisoning but some rats,generally males, showed lameness and ulcerated hocks (probably related to <strong>the</strong>wire floor <strong>of</strong> <strong>the</strong> cage). The only lesion noted in treated but not control groups wasa sore tail, <strong>of</strong>ten with necrosis <strong>of</strong> <strong>the</strong> tip, seen in 2 highdose males and 12 highdosefemales. Body weight gain was slightly though significantly reduced(p
was exposed. The estimated daily ingestion <strong>of</strong> dichlorvos was 6.2 mg via food,3.6 mg via grooming and less than 0.1 mg via drinking water (percutaneousabsorption was unknown). Thus, <strong>the</strong> actual daily intake <strong>of</strong> dichlorvos wasestimated at [sic to] be approximately 10 mg/rat, or 25 mg/kg bw/d[ay] at <strong>the</strong>highest dose. The NOEC was 0.05 mg/m 3 (approximately equal to 0.25 mg/kg/bw/d[ay]), based on <strong>the</strong> inhibition <strong>of</strong> plasma and RBC ChE activity at 0.5 mg/m 3 .‖(Original not sighted; APVMA, 2008a)The APVMA (2008a) evaluated <strong>the</strong> carcinogenic risk <strong>of</strong> DDVP exposure to humansthus:― … oral dosing studies in mice and rats suggest little in <strong>the</strong> way <strong>of</strong> a carcinogenicrisk to humans following dietary or drinking water exposure. The occurrence <strong>of</strong><strong>for</strong>estomach tumours in B6C3F1 mice following gavage dosing suggests thatrepeated exposure to high localised concentrations coupled with some irritancypotential are necessary conditions <strong>for</strong> dichlorvos to be carcinogenic. Importantly,such a scenario is unlikely in humans and <strong>the</strong> main potential exposure <strong>of</strong> <strong>the</strong>general population is by inhaling low concentrations <strong>of</strong> dichlorvos vapour whenused indoors. The most relevant study in <strong>the</strong> database <strong>for</strong> assessing <strong>the</strong> long-termrisk posed by inhaling dichlorvos vapour was a 2-year rat inhalation studyconducted by Blair et al (1974 & 1976). In this study, no treatment-related effectson <strong>the</strong> type, distribution or incidence <strong>of</strong> non-neoplastic or neoplastic lesionsoccurred up to 5 mg/m 3 (achieved concentration <strong>of</strong> 4.7 mg/m 3 ).―Given <strong>the</strong> equivocal evidence <strong>of</strong> carcinogenicity in mice and rats following oraladministration it is worth considering <strong>the</strong> carcinogenic (and genotoxic potential)<strong>of</strong> o<strong>the</strong>r OPs, such as trichlorfon and naled, which are trans<strong>for</strong>med to dichlorvosin vivo.―Trichlorfon or metrifonate is an OP insecticide, which is converted nonenzymicallyto dichlorvos in water, biological fluids and tissues at pH valuesgreater than 5.5. Trichlorfon has been evaluated by Joint FAO/WHO Meeting onPesticide Residues (JMPR) in 1972, 1976 and 1979, <strong>the</strong> International Program onChemical Safety (IPCS) in 1992 (Environmental Health Criteria 132) and <strong>the</strong>Joint WHO/FAO Expert Committee on Food Additives (JECFA) in 2000 (WHOFood Additive Series 45). The International Agency <strong>for</strong> Research on Cancer(IARC) assessed <strong>the</strong> carcinogenicity <strong>of</strong> trichlorfon in 1983 and 1987 classifying itin Group 3 (―The agent is not classifiable as to its carcinogenicity in humans‖).Fur<strong>the</strong>rmore, <strong>the</strong> OCS has evaluated trichlorfon in 1986, 1993, 1994, 1995 and2000. Collectively <strong>the</strong>se evaluations found no evidence <strong>of</strong> any carcinogenicityfollowing dosing by various routes in rats, mice or hamsters. Trichlorfon hadsome genotoxic potential and was mutagenic in bacteria and mammalian cells,however, <strong>the</strong>re was some variability in <strong>the</strong> results which was attributed to <strong>the</strong>purity <strong>of</strong> <strong>the</strong> test material and/or <strong>the</strong> possible <strong>for</strong>mation <strong>of</strong> dichlorvos. While <strong>the</strong>majority <strong>of</strong> genotoxicity assays were negative, trichorfon was found to inducechromosomal damage at relatively high doses. On <strong>the</strong> weight-<strong>of</strong>-evidence it wasconcluded that trichlorfon would be unlikely to pose a genotoxic risk to humans.―Naled is an OP insecticide that converts to dichlorvos in vivo. Naled haspreviously been evaluated by <strong>the</strong> OCS in 2000 and 2003, with no evidence <strong>of</strong>Dichlorvos reassessment – application Page 207 <strong>of</strong> 436
carcinogenicity found in mice following gavage administration. Naled showedevidence <strong>of</strong> mutagenicity in bacterial but not mammalian in vitro assays.‖(Originals not sighted; APVMA, 2008a)And, <strong>the</strong> APVMA concluded:―Forestomach tumours were observed in B6C3F1 mice that received dichlorvosby oral gavage. Dichlorvos was considered to have a localised irritant effect on<strong>the</strong> mouse <strong>for</strong>estomach following gavage dosing, leading to hyperplasia andpossible tumour <strong>for</strong>mation. While <strong>for</strong>estomach tumours are not considereddirectly relevant to humans, and scenarios <strong>of</strong> high oral exposures are unlikely,<strong>the</strong>se findings indicate that repeated exposure to high concentrations <strong>of</strong> dichlorvosis undesirable. There is equivocal evidence <strong>of</strong> carcinogenicity in rats followinglong-term oral dosing. A long-term inhalational study in rats, which simulated <strong>the</strong>most relevant exposure route in humans, showed no evidence <strong>of</strong> carcinogenicity.In addition, related compounds that are metabolised to dichlorvos in vivo showedno carcinogenic potential. On <strong>the</strong> weight-<strong>of</strong>-evidence, dichlorvos is notconsidered to pose a carcinogenic risk to humans.‖ (APVMA, 2008a)Dichlorvos reassessment – application Page 208 <strong>of</strong> 436
14 REPRODUCTIVE TOXICITY 6.8HSNO Classification: Reproductive toxicity – NoKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:Rat 2-generation reproductive study;Rat;CD® (SD)BR;30/sex/group;• Test material: Dichlorvos (Lot No. 802097; 98.3%)• Dose levels: 0, 5.0, 20.0, or 80.0 ppm in <strong>the</strong> drinking water (approx. 0,0.5, 2 and 8 mg/kg b.w./day);• Endpoint:Toxicity and fertility parameters (insemination, fertilityand gestation indices, and gestation period), <strong>the</strong> number <strong>of</strong>pups at birth, <strong>the</strong> number <strong>of</strong> still born pups, <strong>the</strong> ratio <strong>of</strong>male:female pups, litter size, <strong>the</strong> lactation index and pupbirth weight;• Remarks:F 0 parental ratsMortalities and clinical signs: There was no treatment-related effect onmortality in both sexes and on clinical signs in males. Alopecia (bilateral) <strong>of</strong><strong>the</strong> <strong>for</strong>elimbs increased over time in females at 20 and 80 ppm.Effects on bodyweight: During <strong>the</strong> premating period <strong>the</strong>re was no treatmentrelatedeffect on bodyweight. Maternal bodyweight gain during gestationwas 9-15% lower at all doses <strong>of</strong> dichlorvos compared to <strong>the</strong> control but didnot follow a dose-response relationship.Food and water consumption: Food consumption was comparable across allgroups. At 80 ppm, weekly water consumption (g/kg b.w./day) <strong>of</strong> males andfemales was lower than <strong>the</strong> control from prebreeding days 7 to 70,significantly at times. At 80 ppm, maternal water consumption wassignificantly lower than <strong>the</strong> control during gestation and during lactation butwas not statistically significant. The cause <strong>of</strong> <strong>the</strong> lower water consumptionat 80 ppm, due to compound-related toxicity or to <strong>the</strong> reduced palatability <strong>of</strong><strong>the</strong> water, was unclear (note that <strong>the</strong> previous 2-week palatability studyfound reduced water consumption at 240 and 480 ppm).Dichlorvos reassessment – application Page 209 <strong>of</strong> 436
ChE activity: There was a significant (p
ppm during premating days, significantly at certain time points. Duringgestation <strong>of</strong> F 2a litters, maternal water consumption was significantly lower(p
from Charles River Laboratories (CRL) (1996) revealed that <strong>the</strong> femalefertility indices <strong>of</strong> 55% (F 2a ) and 50% (F 2b ) were below <strong>the</strong> averagehistorical control range <strong>of</strong> 60-100%. In both litters, <strong>the</strong> pregnancy index waslower at 80 ppm than in <strong>the</strong> control, suggesting that female fecundity wasreduced with treatment. The number <strong>of</strong> females with live litters was alsoreduced at 80 ppm (both litters), with an apparent increase in <strong>the</strong> stillbirthindex in <strong>the</strong> F 2b litter. The latter was outside <strong>of</strong> <strong>the</strong> historical control range<strong>of</strong> 0-10.2% (CRL 1996). Marginal reductions in pup survival (day 7) and <strong>the</strong>lactation index were noted in both litters but were not considered treatmentrelated.All o<strong>the</strong>r reproduction and lactation indices were unremarkable.Offspring (F 2a and F 2b )At 80 ppm, F 2a pup weights (males and females) were 5-15% lower than <strong>the</strong>controls during <strong>the</strong> entire lactation period [postnatal days 1 (5%), 4 (15%), 7(14%), 14 (12%) and 21 (9%)]. At 80 ppm, F 2b pup weights were also lowerthan <strong>the</strong> controls during <strong>the</strong> lactation period, with a greater effect seen inmales than females [at postnatal days 4 (11/14% M/F), 7 (18/7% M/F), 14(16/3% M/F) and 21 (14/2% M/F)]. Although none <strong>of</strong> <strong>the</strong> findings in F2pups were statistically significant, <strong>the</strong> consistent trend at 80 ppm in bothlitters and with <strong>the</strong> effects seen in F 1 pups means that this effect on pupweight can not be discounted. There were no treatment-related clinical signsobserved in pups during lactation. Macroscopic examination <strong>of</strong> <strong>the</strong> 10pups/sex/dose designated <strong>for</strong> necropsy revealed no treatment relatedabnormalities.• Parental NOAEL =• Parental LOAEL =5 ppm <strong>for</strong> males and females (~0.5 mg/kg bw/d);20 ppm <strong>for</strong> male and female rats based on inhibition<strong>of</strong> plasma, RBC and brain ChE activities (~2 mg/kgbw/d).• Reproductive NOAEL = 20 ppm (~2 mg/kg bw/d);• Reproductive LOAEL = 80 ppm based on reduced fertility and pregnancyindices, increased stillbirths in <strong>the</strong> F2 generation, anda reduction in cycling concomitant with an increasein abnormal cycling in F1 maternal rats (~8 mg/kgbw/d).• Offspring NOAEL =• Offspring LOAEL =• GLP: US EPA, 40 CFR Part 160;20 ppm (~2 mg/kg bw/d);80 ppm based on lower pup weights in bothgenerations (~8 mg/kg bw/d).• Test Guideline:US EPA OPPTS 870.3800; OECD;• Reference source: Tyl RW, Myers CB & Marr MC (1992) ―Two-generationreproductive toxicity study <strong>of</strong> DDVP administered in <strong>the</strong>drinking water to CD® (Sprague-Dawley) rats.‖ RTI IDNo. 60C-4629-170. Lab: Reproductive and DevelopmentalToxicology Laboratory, Centre <strong>for</strong> Life Sciences andDichlorvos reassessment – application Page 212 <strong>of</strong> 436
Toxicology, Chemistry and Life Sciences, ResearchTriangle Institute, Research Triangle Park, North Carolina,USA. Sponsor: AMVAC Chemical Corporation, LosAngeles, Cali<strong>for</strong>nia, USA. Study duration: 9 th January1991 to 23rd June 1992. Report date: 31st August 1992.Tyl RW, Myers CB & Marr MC (1993) ―Addendum t<strong>of</strong>inal report: Two-generation reproductive toxicity study <strong>of</strong>DDVP administered in <strong>the</strong> drinking water to CD®(Sprague-Dawley) rats.‖ RTI ID No. 60C-4629-170. Lab:Reproductive and Developmental Toxicology Laboratory,Centre <strong>for</strong> Life Sciences and Toxicology, Chemistry andLife Sciences, Research Triangle Institute, ResearchTriangle Park, North Carolina, USA. Sponsor: AMVACChemical Corporation, Los Angeles, Cali<strong>for</strong>nia, USA.Study duration: 9th January 1991 to 23rd June 1992.Addendum date: 5th May 1993. Unpublished. (Originalnot sighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Tyl et al. (1992) was carried out to GLP and TestGuideline. Dichlorvos affected reproduction (reduced fertility & pregnancy indices)at maternotoxic doses in rats following administration <strong>for</strong> two generations via <strong>the</strong>drinking water. The NOAEL <strong>for</strong> reproduction and pup toxicity is above <strong>the</strong> NOAEL<strong>for</strong> parental toxicity (respectively: 2 mg/kg b.w./day, 0.5 mg/kg b.w./day), sodichlorvos should not be classified <strong>under</strong> 6.8 <strong>for</strong> reproductive toxicity, as <strong>the</strong>evidence is not strong enough <strong>for</strong> it to meet <strong>the</strong> criteria in Section 16.2.2 <strong>of</strong> <strong>the</strong> UserGuide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).Note that <strong>the</strong> APVMA (2008a) concluded that: ―The NOEL <strong>for</strong> parental toxicity was5 ppm (~0.5 mg/kg bw/d[ay]) based on <strong>the</strong> occurrence <strong>of</strong> toxicologically- andstatistically-significant inhibition <strong>of</strong> plasma, RBC and brain ChE activities at 20 ppm(~2 mg/kg bw/d[ay]). The NOEL <strong>for</strong> pup toxicity was 20 ppm (~2 mg/kg bw/d[ay])based on lower pup weights in both generations at 80 ppm (~8 mg/kg bw/d[ay]). TheNOEL <strong>for</strong> reproductive toxicity was 20 ppm (~2 mg/kg bw/d[ay]) based on reducedfertility and pregnancy indices, increased stillbirths in <strong>the</strong> F 2 generation, and areduction in cycling concomitant with an increase in abnormal cycling in F 1 maternalrats, at 80 ppm (~8 mg/kg bw/d[ay]).‖BACKGROUND:The ATSDR (1997) reported:“Microscopic examination <strong>of</strong> male reproductive tissues (prostate, testes,epididymis) and female reproductive tissues (ovaries, uterus) revealed nochanges attributable to oral dichlorvos exposure during 2-year studies inFischer 344/N rats treated at 4 or 8 mg/kg [b.w.]/day <strong>for</strong> 5 days a week orB6C3F1 mice (males treated at 10 or 20 mg/kg [b.w.]/day, females at 20 or 40mg/kg [b.w.]/day) (NTP 1989). Similar results were obtained in Beagle dogsDichlorvos reassessment – application Page 213 <strong>of</strong> 436
eceiving dichlorvos by capsule <strong>for</strong> 52 weeks at up to 3 mg/kg [b.w.]/day(AMVAC Chemical Corp. 1990). Male reproductive tissues examined were <strong>the</strong>testes, prostate, and epididymides; female tissues examined were <strong>the</strong> cervix,ovaries, uterus, and vagina.“In a reproductive toxicity study involving male CF-1 mice, groups <strong>of</strong> 16 micewere exposed to atmospheres containing dichlorvos at 0, 30, or 55 mg/m 3 <strong>for</strong>16 hours (0, 3.3, or 6.1 ppm) (Dean and Thorpe 1972). Following dosing, eachmale mouse was caged with 3 randomly selected females <strong>for</strong> 7 days; thisprocedure was repeated weekly <strong>for</strong> a total <strong>of</strong> 8 weeks. Thirteen days after <strong>the</strong>presumed mating (which occurred by <strong>the</strong> middle <strong>of</strong> <strong>the</strong> week), <strong>the</strong> femalemice were sacrificed and <strong>the</strong> uteri removed <strong>for</strong> examination. There were nodifferences between control and treated mice in <strong>the</strong> number <strong>of</strong> early fetaldeaths, late fetal deaths, or live fetuses found in <strong>the</strong> pregnant females. Thepercentages <strong>of</strong> pregnancies <strong>for</strong> females mated to males exposed to 30 or 55mg/m 3 (3.3 or 6.1 ppm) <strong>for</strong> 16 hours ranged from 67 to 88% and 63-92%,respectively; <strong>for</strong> controls, <strong>the</strong> percentages ranged from 73 to 88%. Under<strong>the</strong>se exposure conditions, dichlorvos did not appear to affect <strong>the</strong> fertility <strong>of</strong>male CF-1 mice. [NOAEL = 6.1 ppm, highest concentration tested.]“In ano<strong>the</strong>r experiment in this study, similar results were obtained <strong>for</strong> malemice exposed <strong>for</strong> 4 weeks to atmospheres containing 2.1 or 5.8 mg/m 3 (0.23or 0.64, respectively) dichlorvos <strong>for</strong> 23 hours a day (Dean and Thorpe 1972).[NOAEL = 0.64 mg/m 3 , highest concentration tested.] (Originals not sighted;ATSDR, 1997)WHO (1993) reported:―Male and female Crl:CD3-1 mice were exposed to dichlorvos concentrations <strong>of</strong>0, 1.9, 3.0 or 4.6 mg/m 3 , generated from dichlorvos-impregnated PVC strips in<strong>the</strong>ir cages. Exposure began 4 days prior to <strong>for</strong>mation <strong>of</strong> breeding groups (3females and 1 male) and continued throughout pregnancy. Signs <strong>of</strong> intoxicationwere not observed. Plasma ChE activity was significantly inhibited (by 90%, 93%and 95% in <strong>the</strong> 1.9, 3.0 and 4.6 mg/m 3 groups, respectively) when measured onday 4 after beginning <strong>of</strong> treatment. Gestation length, number <strong>of</strong> litters, litterfrequency and mean litter size were comparable to controls. No grossly detectablecongenital anomalies were detected in any <strong>of</strong> <strong>the</strong> <strong>of</strong>fspring (Casebolt et al., 1990).―A 3-generation, 2-litter/generation reproduction study in rats summarized byWHO (1988) was negative at doses up to 235 ppm in <strong>the</strong> diet, equivalent to 12mg/kg bw/day (Wi<strong>the</strong>rup et al., 1965). [The low dose rate is noted.]―Groups <strong>of</strong> 14 male NMRI/Han mice received ei<strong>the</strong>r a single oral dose <strong>of</strong> 40mg/kg bw dichlorvos in olive oil or 18 daily oral doses <strong>of</strong> 0 or 10 mg/kg bwdichlorvos in olive oil. On days 9, 18, 27, 36, 54 and 63, two animals from eachgroup were killed and <strong>the</strong>ir testes examined histologically. A significant increasein <strong>the</strong> number <strong>of</strong> damaged seminiferous tubules (desquamation, decreases in cellpopulation, "holes") was observed in both dichlorvos groups. The supportingSertoli cells were also damaged, which may have resulted in <strong>the</strong> above effects. InDichlorvos reassessment – application Page 214 <strong>of</strong> 436
addition, <strong>the</strong>re was an increase in <strong>the</strong> number and hypertrophy <strong>of</strong> Leydig cells. Noexplanation was given <strong>for</strong> <strong>the</strong>se effects (Krause & Homola, 1972, 1974).―An increased incidence, just above background, <strong>of</strong> sperm abnormalities, wasobserved in a screening study on hybrid mice given five daily i.p. injections <strong>of</strong> 10mg/kg bw dichlorvos (approximately half <strong>the</strong> LD 50 ). At lower doses, 1 mg/kg bw,<strong>the</strong> number <strong>of</strong> sperm abnormalities was ei<strong>the</strong>r similar to or lower than those in <strong>the</strong>controls (Wyrobek & Bruce, 1975).―Groups <strong>of</strong> 16 male juvenile Wistar rats received ei<strong>the</strong>r 20 mg/kg bw dichlorvosin olive oil on days 4 and 5, 10 mg/kg bw dichlorvos in olive oil daily from days 4to 23, or 0.1 ml olive oil daily from days 4 to 23. On days 6, 12, 18, 26, 34, and50 <strong>of</strong> life, two rats from each group were sacrificed. Histological examination <strong>of</strong><strong>the</strong> testes showed slight reduction in <strong>the</strong> number <strong>of</strong> spermatogenic cells andLeydig cells. All changes were reversed by <strong>the</strong> 50th day <strong>of</strong> life. It was assumedthat a reduction in testosterone syn<strong>the</strong>sis resulted in damage to <strong>the</strong> spermatogeniccells (Krause et al., 1976).―In a subsequent experiment measurement <strong>of</strong> testosterone concentrations in <strong>the</strong>testes, and luteinizing hormone (LH) and follicle stimulating hormone (FSH)concentrations in serum showed no differences between treated animals and oliveoiltreated controls (Krause, 1977). However, in this study <strong>the</strong> use <strong>of</strong> a differentdosing regimen (10 mg/kg bw by gavage every o<strong>the</strong>r day <strong>for</strong> 2 weeks) prevented astrict comparison with <strong>the</strong> earlier study by Krause et al. (1976).―Fifty-five male Wistar rats (aged 5 months) were orally administered dichlorvosat levels <strong>of</strong> 5 or 10 mg/kg bw every o<strong>the</strong>r day <strong>for</strong> 8 weeks. Eleven rats werekilled every 4 weeks. No change was seen in body-weight gain or testes weight.The score values <strong>of</strong> <strong>the</strong> seminal cellular system decreased after 4-8 weeks <strong>of</strong>treatment, but were restored 8 weeks after <strong>the</strong> end <strong>of</strong> treatment (Fujita et al.,1977).‖ (Originals not sighted; WHO, 1993)15 DEVELOPMENTAL TOXICITY 6.8HSNO Classification: Developmental toxicity – NoKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:Rat teratogenicity study;Rat;CD® SD rats;25 females/group;• Test material: Dichlorvos (Lot No. 802097; 96.86%);• Dose levels:0, 0.1, 3.0, or 21.0 mg/kg b.w./day;Dichlorvos reassessment – application Page 215 <strong>of</strong> 436
• Endpoint:Appearance, behaviour, mortality, food consumption, andbody weight gain <strong>of</strong> <strong>the</strong> dams, reproduction parameters,embryotoxicity, foetotoxicity or teratogenicity;• Remarks:Maternal rats: There were no deaths. Cholinergic signs were evident at 21.0mg/kg b.w./day during <strong>the</strong> dosing period and included tremors, pronepositioning, excitability, leaning/swaying and lower jaw movement.Tremors were reported to occur within 10-60 minutes <strong>of</strong> dosing. Ratsrecovered following <strong>the</strong> cessation <strong>of</strong> dosing. Treatment-related clinical signswere not observed in any o<strong>the</strong>r group. The average bodyweight <strong>of</strong> <strong>the</strong> 21.0mg/kg b.w./day group was significantly lower (p
• Maternal toxicity NOAEL =• Maternal toxicity LOAEL =3.0 mg/kg b.w./day;21.0 mg/kg b.w./day, based oncholinergic signs, decreased body weightand food consumption.• Developmental toxicity NOAEL = 21.0 mg/kg b.w./day, <strong>the</strong> highest dosetested;• Developmental toxicity LOAEL was not established.• GLP: US EPA; 40 CFR Part 160;• Test Guideline:• Reference:• Reliability:No in<strong>for</strong>mation;Tyl RW, Marr MC & Myers CB (1990a) Developmentaltoxicity evaluation <strong>of</strong> DDVP administered by gavage toCD (Spragues-Dawley) rats. RTI ID No. 60C-4629-10/20.Lab: Reproductive and Developmental ToxicologyLaboratory, Centre <strong>for</strong> Life Sciences and Toxicology,Chemistry and Life Sciences, Research Triangle Institute,Research Triangle Park, North Carolina, USA. Sponsor:AMVAC Chemical Corporation, Los Angeles, Cali<strong>for</strong>nia,USA. Study duration: Unspecified. Report date: 22ndFebruary 1991. Unpublished. (Original not sighted;APVMA, 2008a);Klimisch score 2 = reliable with restrictions;KEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/numbers:Rabbit teratogenicity study;Rabbit;New Zealand White;16 females/group;• Test material: Dichlorvos (Lot No. 802097; 96.86%);• Dose levels:0, 0.1, 2.5, or 7.0 mg/kg b.w./day;Dichlorvos reassessment – application Page 217 <strong>of</strong> 436
• Endpoint:Appearance, behaviour, mortality, food consumption, andbody weight gain <strong>of</strong> <strong>the</strong> dams, reproduction parameters,embryotoxicity, foetotoxicity or teratogenicity;• Remarks:Maternal rabbits: Two and four pregnant rabbits died in <strong>the</strong> 2.5 and 7.0mg/kg b.w./day groups, respectively. Two females from <strong>the</strong> 0.1 mg/kgb.w./day group were removed from <strong>the</strong> study because <strong>of</strong> early delivery.Treatment-related clinical signs were evident in <strong>the</strong> 7.0 mg/kg b.w./daygroup during <strong>the</strong> dosing period (gestation day 7-19) and included ataxia (2-6rabbits), increased respiration (2), subdued behaviour (2), rapid breathing(2-3), salivation (2-3), fine motor tremors (2) and lurching (2). Theseclinical signs were not observed in any o<strong>the</strong>r group. Average maternalbodyweight gain was lower than <strong>the</strong> control at 2.5 and 7.0 mg/kg b.w./dayover gestation day 7-19 (67 and 58%, respectively). When maternalbodyweight was corrected <strong>for</strong> gravid uterine weight, only <strong>the</strong> bodyweightgain at 7.0 mg/kg b.w./day appeared to be lower than <strong>the</strong> control (~54%lower). None <strong>of</strong> <strong>the</strong>se effects on bodyweight were statistically significant.There was a slight but significant reduction in maternal food consumptionduring <strong>the</strong> dosing period (gestation day 7-19), which followed a significantlinear trend (p
Research Triangle Park, North Carolina, USA. Sponsor:AMVAC Chemical Corporation, Los Angeles, Cali<strong>for</strong>nia,USA. Study duration: 19th June 1990 to 2 nd August 1990.Report date: 22nd February 1991. Unpublished. (Originalnot sighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Tyl (1990a and 1990b) were conducted to GLP. Theadverse effects noted appear consistent with significant maternal toxicity, with noevidence <strong>of</strong> particular developmental sensitivity. Dichlorvos should not be classified<strong>under</strong> 6.8 <strong>for</strong> developmental toxicity, as <strong>the</strong>re is no evidence that it meets <strong>the</strong> criteriain Section 16.2.2 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong>HSNO Act (ERMA, 2008).BACKGROUND:The ATSDR (1997) reported:“No adverse developmental effects were observed in CF-1 mice treated bygavage with 60 mg/kg [b.w.]/day dichlorvos during gestation days 6-15(Schwetz et al. 1979). There was no significant effect on implantations, meannumber <strong>of</strong> fetuses per litter, incidence or distribution <strong>of</strong> resorptions, or onfetal body measurements. Similar results were observed in New Zealandrabbits treated by gavage with 5 mg/kg [b.w.]/day over gestation days 6-18(Schwetz et al. 1979).“Several animal studies examining developmental toxicity during continuousinhalation exposure to dichlorvos are available. A study in which pregnantmice and rabbits were exposed to dichlorvos only during <strong>the</strong> organogenesisperiod <strong>of</strong> gestation showed no significant effect on development (Schwetz etal. 1979). In this study, pregnant CF-1 mice were exposed to 4 mg/m 3 (0.44ppm) dichlorvos <strong>for</strong> 7 hours a day during gestation days 6-15. At sacrifice onday 18, no significant effects were seen on <strong>the</strong> mean number <strong>of</strong> fetuses perlitter, <strong>the</strong> incidence or distribution <strong>of</strong> resorptions, or on fetal bodymeasurements. Twenty control litters and 15 litters from treated animalswere examined in this study. [NOAEL = 0.44 ppm].“There was no difference between <strong>the</strong> litters from controls and dichlorvostreateddams. Pregnant New Zealand rabbits exposed to 4 mg/m 3 (0.44 ppm)<strong>for</strong> 7 hours a day during gestation days 6-18 also showed no evidence <strong>of</strong>developmental toxicity (Schwetz et al. 1979). Mean number <strong>of</strong> fetuses perlitter, incidence or distribution <strong>of</strong> resorptions and fetal body measurementswere similar in 14 control litters and 19 treated litters. [NOAEL = 0.44 ppm].“Groups <strong>of</strong> 15 pregnant Catworth E rats were exposed to atmospherescontaining 0, 0.25, 1.25, or 6.25 mg/m 3 (0, 0.03, 0.14, or 0.69 ppm)throughout <strong>the</strong>ir 20-day gestation period (Thorpe et al. 1972). At <strong>the</strong> end <strong>of</strong>20 days, <strong>the</strong> rats were sacrificed and <strong>the</strong> uteri removed <strong>for</strong> examination. Thenumber <strong>of</strong> live fetuses, late fetal deaths, and resorption sites were noted, andDichlorvos reassessment – application Page 219 <strong>of</strong> 436
live fetuses were weighed and examined <strong>for</strong> external mal<strong>for</strong>mations.Approximately half <strong>the</strong> fetuses in each litter were processed <strong>for</strong> alizarinstainedpreparations <strong>of</strong> <strong>the</strong> skeleton, and <strong>the</strong> o<strong>the</strong>r half were fixed in Bouin’sfluid and examined <strong>for</strong> structural abnormalities <strong>of</strong> <strong>the</strong> viscera by transversesections. Exposure <strong>of</strong> dams to all three concentrations <strong>of</strong> dichlorvos did notaffect <strong>the</strong> number <strong>of</strong> fetal resorptions, late fetal deaths, litter size, or meanweight per fetus. One fetus in <strong>the</strong> litter <strong>of</strong> dams in <strong>the</strong> 0.25 mg/m3 group hadskeletal defects and gastroschisis. Because no o<strong>the</strong>r fetuses from damsexposed to <strong>the</strong> same or higher concentrations had <strong>the</strong>se defects, <strong>the</strong> authorsconcluded that <strong>the</strong>y were not exposure-related. Brain and erythrocyteacetylcholinesterase activities were inhibited 83 and 88%, respectively, indams in <strong>the</strong> high-exposure (6.25 mg/m 3 ) group, suggesting thatacetylcholinesterase inhibition is not associated with teratogenicity.Measurement <strong>of</strong> acetylcholinesterase activities in <strong>the</strong> pups was notper<strong>for</strong>med. [NOAEL = 0.69 ppm].“In a parallel experiment conducted on groups <strong>of</strong> 20 pregnant Dutch rabbits(Thorpe et al. 1972), similar results were seen. Dams exposed to dichlorvosat 6.25 mg/m 3 (0.69 ppm), as in <strong>the</strong> previously described rat study, had highmortality (16 <strong>of</strong> 20 died). Consequently, <strong>the</strong> doses used in this experimentwere 0, 0.25, 1.25, 2, and 4 mg/m 3 (0, 0.03, 0.14, 0.22, and 0.44 ppm) over <strong>the</strong>28-day rabbit gestational period. Six <strong>of</strong> <strong>the</strong> 20 rabbits exposed to 4 mg/m3died. In both <strong>the</strong> 4 and 6.25 mg/m 3 exposure groups, spiking <strong>of</strong> <strong>the</strong> exposureconcentration occurred. Sizes <strong>of</strong> litters, fetal resorptions, and late fetal deathswere unaffected by inhalation exposure to dichlorvos. Mean fetal weightswere significantly depressed (23.1 ± 0.98 g <strong>for</strong> controls and 20.2 ± 0.98 g <strong>for</strong><strong>the</strong> 4 mg/m 3 exposure group), but <strong>the</strong> authors ascribed this to maternaltoxicity. Clinical signs were similar to signs <strong>for</strong> dams exposed to 6.25 mg/m 3 ;6 dams out <strong>of</strong> 20 in this group died during <strong>the</strong> study. Three fetuses fromgroups that had not been exposed to dichlorvos had gastroschisis. Two deadfetuses from one litter in <strong>the</strong> 4 group had cleft palates, but this may also be aresult <strong>of</strong> maternal toxicity ra<strong>the</strong>r than a developmental effect.” [NOAEL =0.44 ppm]. (Originals not sighted; ATSDR, 1997)The APVMA and WHO also reported on <strong>the</strong> studies by Schwetz et al. (1979) andThorpe et al. (1972) (Originals not sighted; APVMA, 2008a; WHO, 1988).Dichlorvos reassessment – application Page 220 <strong>of</strong> 436
16 REPRODUCTIVE OR DEVELOPMENTAL TOXICITY ON OR VIA LACTATION 6.8CHSNO Classification: Reproductive or developmental effects on or vialactation – Insufficient dataKEY STUDY: (see Section 14 Reproductive Toxicity 6.8 above <strong>for</strong> fuller details)• Type <strong>of</strong> study:Rat 2-generation reproductive study;• Remarks:Offspring (F 1a litter)There were no treatment-related clinical signs observed in F 1a pups duringlactation.F 1 parental ratsReproductive parameters: Marginal reductions in pup survival (day 7) and<strong>the</strong> lactation index were noted in both litters but were not consideredtreatment-related. All o<strong>the</strong>r reproduction and lactation indices wereunremarkable.Offspring (F 2a and F 2b )At 80 ppm, F 2a pup weights (males and females) were 5-15% lower than <strong>the</strong>controls during <strong>the</strong> entire lactation period [postnatal days 1 (5%), 4 (15%), 7(14%), 14 (12%) and 21 (9%)]. At 80 ppm, F 2b pup weights were also lowerthan <strong>the</strong> controls during <strong>the</strong> lactation period, with a greater effect seen inmales than females [at postnatal days 4 (11/14% M/F), 7 (18/7% M/F), 14(16/3% M/F) and 21 (14/2% M/F)]. Although none <strong>of</strong> <strong>the</strong> findings in F 2pups were statistically significant, <strong>the</strong> consistent trend at 80 ppm in bothlitters and with <strong>the</strong> effects seen in F 1 pups means that this effect on pupweight can not be discounted. There were no treatment-related clinical signsobserved in pups during lactation.• Reference source: Tyl RW, Myers CB & Marr MC (1992 & 1993)Unpublished. (Original not sighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Tyl et al. (1992) was carried out to GLP and TestGuideline. There is insufficient evidence to show or discount a specific substanceeffect on or via lactation. A two-generation reproductive toxicity study in ratsshowed reductions pup weight during lactation (F 1a , F 2a , F 2b ), suggestive <strong>of</strong> areduction in lactation or reduced maternal care, but at doses causing frank maternaltoxicity and reduced maternal water intake. Dichlorvos should not be classified<strong>under</strong> 6.8 <strong>for</strong> reproductive or developmental toxicity on or via lactation, as <strong>the</strong>Dichlorvos reassessment – application Page 221 <strong>of</strong> 436
evidence is insufficiently suggestive that it meets <strong>the</strong> criteria in Section 16.2.2 <strong>of</strong> <strong>the</strong>User Guide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).BACKGROUND:The potential adverse reproductive or developmental effects on or via lactation bydichlorvos has not been specifically reported by national regulatory agencies.The ATSDR reported:“Because it is rapidly metabolized, dichlorvos has not been detected in blood,adipose tissue, breast milk, or any o<strong>the</strong>r tissue samples from <strong>the</strong> generalpopulation or from populations with occupational exposures.” (Originals notsighted; ATSDR, 1997)Dichlorvos reassessment – application Page 222 <strong>of</strong> 436
17 SPECIFIC TARGET ORGAN TOXICITY 6.9 (SINGLE DOSE – ORAL)HSNO Classification: Specific target organ toxicity (Single dose – oral) –6.9AKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:Acute Neurotoxicity Study;Rat;SD Crl:CD®BR;12/sex/group;• Test Material: Dichlorvos (Lot No. 802097; 97.87%);• Dose levels:• Endpoint:0, 0.5, 35 or 70 mg/kg b.w. in deionised water (dosevolume was 10 mL/kg b.w.) by gavage;Mortality and clinical signs: pupillary reflex, generalappearance and condition, open field observations(arousal, surface righting reflex and gait, <strong>for</strong>elimb andhindlimb grasp reflexes); bodyweights; FunctionalObservation Battery (FOB); locomotor activity; necropsy;• Remarks: Mortalities, clinical signs and bodyweight effects: At 70mg/kg b.w., 2 males and 5 females died within 4 h <strong>of</strong>dosing. There were no o<strong>the</strong>r deaths. Necropsy revealedthat one <strong>of</strong> <strong>the</strong> deceased males probably perished due to anintubation error.FOB: The pretreatment FOB was unremarkable. Treatment-related effectson FOB findings were restricted to day 0, while <strong>the</strong>re were no effects at day7 and 14. The majority <strong>of</strong> abnormal FOB findings at and above 35 mg/kgb.w. were different (higher or lower) than historical control values <strong>for</strong> age,sex and time-matched rats from <strong>the</strong> per<strong>for</strong>ming laboratory.Home cage observationsAt 70 mg/kg b.w., <strong>the</strong>re was a significant decrease (p
(p
There was a significant dose-related reduction (p
June 1992. Report date: 15th January 1993. Unpublished.(Original not sighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Lamb (1993a) was conducted to GLP and TestGuidelines. The LOAEL (35 mg/kg b.w.) <strong>for</strong> rat is below <strong>the</strong> threshold <strong>for</strong> 6.9Aclassification <strong>for</strong> single dose exposures in Table 17.1 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong>Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).BACKGROUND:The ATSDR (1997) reported:“Neurological effects have been seen in many studies in animals after acute oralexposure to dichlorvos. Male Fischer 344 rats exposed to dichlorvos by olive oilgavage during an LD50 study had signs <strong>of</strong> excessive cholinergic stimulationincluding salivation, tremors, lacrimation, fasciculations, irregular respiration, andprostration (Ikeda et al. 1990). The authors did not report <strong>the</strong> dose at which <strong>the</strong>sesigns appeared; <strong>the</strong> LD50 calculated from <strong>the</strong> study was 97.5 mg/kg [b.w.]. In 2o<strong>the</strong>r studies, in which clinical signs were not reported, single oral doses <strong>of</strong> 40mg/kg [b.w.] dichlorvos in male rats resulted in a 70% inhibition <strong>of</strong> brainacetylcholinesterase after one hour (Teichert et al. 1976) and an 83% inhibitionafter 15 minutes (Pachecka et al. 1977).“In greyhound dogs receiving 11 or 22 mg/kg [b.w.] in a single dose, signs <strong>of</strong>neurological toxicity appeared within 7-15 minutes <strong>of</strong> dosing (Snow and Watson1973). Restlessness was seen initially, followed by increased salivation. musclefasciculations, involuntary urination, diarrhea, sometimes bloody, and tenesmus[sic: interpreted as excessive defecation]. There was no apparent difference inseverity <strong>of</strong> clinical signs between dogs given 11 or 22 mg/kg [b.w.]. Erythrocyteacetylcholinesterase was determined in 11 dogs, and <strong>the</strong> values ranged from 69 to97% inhibition. The dog with 97% inhibition <strong>of</strong> erythrocyte acetylcholinesterase(dosed at 11 mg/kg [b.w.]) had severe clinical signs <strong>of</strong> intoxication but survived.Crossbred pigs receiving single doses from 18 to 560 mg/kg [b.w.] had clinicalsigns <strong>of</strong> neurological toxicity including hypoactivity, vomiting, ataxia, musclefasciculations, uncoordinated movements, frothy salivation, and defecation(Stanton et al. 1979).” (Originals not sighted; ATSDR, 1997)Dichlorvos reassessment – application Page 226 <strong>of</strong> 436
18 SPECIFIC TARGET ORGAN TOXICITY 6.9 (SINGLE DOSE – DERMAL)HSNO Classification: Specific target organ toxicity (Single dose – dermal) –6.9BKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test Material:• Dose levels:• Endpoint:Acute Dermal Toxicity (LD 50 ) Study;Rat;RAC;6/sex/group;Dichlorvos (source & purity not given);80-200 mg/kg b.w. to 10 cm 2 area <strong>of</strong> <strong>the</strong> shaved skin <strong>for</strong>24 hours ei<strong>the</strong>r as concentrate or in PEG (10% v/v);Mortality and clinical signs; necropsy;• Remarks:The LD 50 (males plus females) was 210 mg/kg b.w., with most deathsoccurring after 24 hour.No adverse signs were observed at 80 or 100 mg/kg b.w. (in PEG).At 150 or 200 mg/kg b.w. (concentrate), adverse signs were observed within15-30 minutes <strong>of</strong> application and included dose-dependent trismus, tonicclonicspasms <strong>of</strong> limb muscles, prostration, exophthalmus, dyspnoea, andlachrymation and secretion from <strong>the</strong> Hardersche (Harderian) glands. Symptomspersisted <strong>for</strong> up to 3 days but surviving animals recovered fully after 5-6 days.Necropsy <strong>of</strong> animals dying during <strong>the</strong> observation period revealed acute liver,spleen and kidney congestion, bloated intestines and inflamed peritoneum.Animals sacrificed after 7 days showed enlarged livers, and bloated or slackintestines. No o<strong>the</strong>r macroscopic effects were reported.No skin irritation was evident.• NOAEL =• LOAEL =• GLP:100 mg/kg b.w.;150 mg/kg b.w., based on clinical signs <strong>of</strong> neurotoxicity;No in<strong>for</strong>mation;Dichlorvos reassessment – application Page 227 <strong>of</strong> 436
• Test Guideline:No in<strong>for</strong>mation;• Reference source: Tierfarm, Sissel, Switzerland (1969b) ―Report on <strong>the</strong>determination <strong>of</strong> <strong>the</strong> acute dermal LD50 to <strong>the</strong> rat <strong>of</strong>DDVP technical.‖ No study/report No. Lab/Sponsor:unspecified. Unpublished. [Novartis; sub 11605] (Originalnot sighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: There is no in<strong>for</strong>mation as to whe<strong>the</strong>r or not Tierfarm(1969b) was conducted to Test Guidelines, but it was pre-GLP. The LOAEL (150mg/kg b.w.) <strong>for</strong> rat is below <strong>the</strong> threshold <strong>for</strong> 6.9B classification <strong>for</strong> single doseexposures in Table 17.1 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong> Thresholds and Classifications in<strong>the</strong> HSNO Act (ERMA, 2008).Dichlorvos reassessment – application Page 228 <strong>of</strong> 436
19 SPECIFIC TARGET ORGAN TOXICITY 6.9 (SINGLE DOSE – INHALATION)HSNO Classification: Specific target organ toxicity (Single dose – inhalation)– 6.9AKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test Material:Acute Inhalation Toxicity, LC 50 (4hours, head-only);vapour/aerosol;Rat;Wistar (Bor:WISW);5 (vapour) or 10 (aerosol)/sex/group;Dichlorvos (98.7 % pure, batch no. 809 436 388, lot no.3379);• Dose levels: Vapour: 342 mg/m 3 (nominal), 116 mg/m 3 (analysed) <strong>for</strong> 4hours;Aerosol: 230-1926 mg/m 3 <strong>for</strong> 4 hours;• Endpoint: Mortality (LC 50 );• Remarks:For <strong>the</strong> vapour experiment, 5 animals/sex were exposed <strong>for</strong>4 hours to a nominal concentration <strong>of</strong> 342 mg/m 3 (<strong>the</strong>analysed concentration was 116 mg/m 3 , <strong>the</strong> maximumachievable as vapour). All animals showed adverse signsincluding bristling and ungroomed coat, reduced motilityand high gait but <strong>the</strong>re were no deaths. No effects onweight gain were observed during <strong>the</strong> 14-day observationperiod and autopsy revealed no treatment-related grosseffects.A lethal vapour concentration could not be generated(maximum concentration was 116 mg/m 3 ); LC 50 > 116mg/m 3 (0.116 mg/L).In <strong>the</strong> aerosol experiment, 10 animals/sex were exposed tonominal air concentrations <strong>of</strong> 1500 - 15000 μL/m 3 (230-1926 mg/m 3 ) <strong>for</strong> 4 hours, with <strong>the</strong> particle mass mediandiameter ranging from 2.8 to 6.4 μm.Adverse signs, evident immediately after exposure (i.e.when rats were removed from tubes) were severe muscletremors and weakness, convulsions, recumbence on side,ataxia, apathy and dyspnoea. More persistent signsincluded ungroomed coat, bristling fur and high gait. AllDichlorvos reassessment – application Page 229 <strong>of</strong> 436
surviving animals appeared to behave normally during <strong>the</strong>second week <strong>of</strong> observation.Body weight gain was normal.Animals that died during exposure showed a number <strong>of</strong>changes at autopsy: distended lung; oedematous and pale,patchy liver with lobulation; pale spleen and kidney;hyperaemia <strong>of</strong> <strong>the</strong> glandular stomach and serosa <strong>of</strong> <strong>the</strong>small intestine; and blood and mucus in <strong>the</strong> gut. Notreatment-related gross effects were observed in thoseanimals surviving <strong>the</strong> 14-day observation period.• NOAEL =• LOAEL =• GLP:not established;0.23-1.926 mg/L (230-1926 mg/m 3 ), based on clinicalsigns <strong>of</strong> neurotoxicity [Note: <strong>the</strong> available summaryimplies adverse effects were noted at all testedconcentrations, but <strong>the</strong> NOAEL/LOAELs were notstated.];Yes;• Test Guideline: Stated con<strong>for</strong>ming to OECD [403?];• Reference source:• Reliability:Pauluhn J (1984) ―Dichlorvos (L15/20, DDVP) study <strong>for</strong>acute inhalation toxicity.‖ Report No. 13124;Lab/Sponsor: Bayer AG Institute <strong>of</strong> Toxicology,Wuppertal-Eberfeld. Report date: 12th December 1984.(Original not sighted.) (APVMA, 2008a);Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Pauluhn (1984) was conducted to GLP and TestGuidelines. The LOAEL (at 0.23 mg/L) is below <strong>the</strong> threshold <strong>for</strong> 6.9Aclassification <strong>for</strong> single dose exposures in Table 17.1 <strong>of</strong> <strong>the</strong> User Guide to <strong>the</strong>Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008).Dichlorvos reassessment – application Page 230 <strong>of</strong> 436
20 SPECIFIC TARGET ORGAN TOXICITY 6.9 (REPEAT DOSE – ORAL)HSNO Classification: Specific target organ toxicity (Repeat dose – oral) –6.9AKEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/numbers:Dog 2-year dietary study;Dog;Beagle;3/sex/group;• Test material: Dichlorvos; unspecified batch, 93%;• Dose levels: 0, 0.1, 1.0, 10.0, 100 or 500 ppm (equivalent to: 0, 0.0025,0.025, 0.25, 2.5 or 12.5 mg /kg b.w./day); Volatilisationreduced <strong>the</strong> concentration <strong>of</strong> dichlorvos present in <strong>the</strong> feed.Pooled samples taken daily during each week indicatedthat average concentrations were 0.09, 0.32, 3.2, 32.0 and256 ppm at 0.1, 1.0, 10.0, 100 or 500 ppm, respectively.Dichloroacetaldehyde (DCA) was also detected at 0.60,6.4 and 20.0 ppm in <strong>the</strong> 10.0, 100 or 500 ppm diets,respectively.• Endpoint:Clinical signs, mortality, body weight gain, foodconsumption, clinical chemistry, haematology or urinaryparameters, organ weight, gross/microscopic abnormalitiesand tumour incidences; plasma, RBC and brain AChEactivities;• Remarks:Mortalities, clinical signs and effects on body weight, food consumption,haematology, clinical chemistry and urinalysis: One male dog (500 ppmgroup) was sacrificed in extremis after 68 weeks with a diagnosis <strong>of</strong>bronchitis and pneumonia. There were no treatment-related clinical signs,effects on food consumption or on bodyweight. There was no treatmentrelatedeffect on any haematology, clinical chemistry or urinalysisparameter.ChE activity: There was dose-dependent depression <strong>of</strong> RBC ChE activity indogs, particularly during <strong>the</strong> earlier periods <strong>of</strong> treatment. For males this wasevident at 10-100 ppm and in females at 100-500 ppm, with RBC activityreduced 50-90% in both sexes over <strong>the</strong>se concentrations. Plasma ChEfollowed a similar trend but was only depressed in dogs from <strong>the</strong> 100 and500 ppm groups. ChE activity had returned to pretreatment levels at <strong>the</strong> endDichlorvos reassessment – application Page 231 <strong>of</strong> 436
<strong>of</strong> 2-year treatment period. No effects <strong>of</strong> treatment were observed on <strong>the</strong>ChE activity in brain cortex or brain stem at necropsy.Necropsy: Absolute and relative liver weights in males <strong>of</strong> <strong>the</strong> 100 and 500ppm group and females <strong>of</strong> <strong>the</strong> 500 ppm group were marginally higher thanthose <strong>of</strong> controls. This was reported as <strong>of</strong> 'borderline significance' but nodetails <strong>of</strong> statistical methodologies were provided. No o<strong>the</strong>r effects on organweight were observed. Pathology revealed a number <strong>of</strong> spontaneous lesions,with chronic bronchitis, pulmonary granulomas and renal granulomas <strong>the</strong>most common. These were unrelated to treatment. Rarefaction <strong>of</strong> <strong>the</strong>cytoplasm <strong>of</strong> hepatic cells, with cellular enlargement and thickening <strong>of</strong> <strong>the</strong>cell wall, increased in incidence and severity with dose; graded as slight in1/3 females at 10 ppm and 1/3 males and 3/3 females at 100 ppm, and asmoderate in all 500 ppm dogs. There were no architectural changes to <strong>the</strong>liver. The hepatocellular effects were <strong>of</strong> such magnitude that liver functionwas not likely to have been affected, and serum liver enzymes revealed nohepatic damage. Two independent pathologists, blind to <strong>the</strong> experimentalprotocol, were reported to have not seen significant differences inhepatocytes between treated and control animals.• NOAEL =• LOAEL =• GLP:• Test Guideline:0.32 ppm (equivalent to: 0.008 mg/kg b.w./day);3.2 ppm (equivalent to 0.08 mg/kg b.w./day) based oninhibition <strong>of</strong> RBC ChE activity in males.No;No in<strong>for</strong>mation;• Reference source: Jolley PW, Stemmer KL & Pfitzer EA (1967) ―The effectsexerted upon beagle dogs during a period <strong>of</strong> two years by<strong>the</strong> introduction <strong>of</strong> Vapona® insecticide into <strong>the</strong>ir dailydiets.‖ Report/Study No. unspecified. Lab: KetteringLaboratory, University <strong>of</strong> Cincinnati, Ohio, USA. Reportdate: 19th January 1967. Unpublished. (Original notsighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions (<strong>the</strong> APVMAconcluded that <strong>the</strong> study was adequate <strong>for</strong> assessment);Dichlorvos reassessment – application Page 232 <strong>of</strong> 436
KEY STUDY:• Type <strong>of</strong> study:• Species:• Strain:• Sex/numbers:• Test material:• Dose levels:• Endpoint:Dog 52-week capsule study;Dog;Beagle;4/sex/group;Dichlorvos (Lot No. 802097; 100% purity);0, 0.05 (0.1 <strong>for</strong> <strong>the</strong> 1 st 3 weeks), 1.0 or 3.0 mg/kg b.w./day;Clinical signs, mortality, body weight gain, foodconsumption, clinical chemistry, haematology or urinaryparameters, organ weight, gross/microscopic abnormalitiesand tumour incidences; plasma, RBC and brain AChEactivities;• Remarks:Mortalities and clinical signs: No dogs died during <strong>the</strong> study. There was arange <strong>of</strong> incidental clinical signs observed in both <strong>the</strong> control and treatmentgroups, but none that were attributable to <strong>the</strong> test compound. There was aclear treatment-related effect on <strong>the</strong> occurrence <strong>of</strong> emesis, which was morepronounced in males than females.Bodyweights and food consumption: There appeared to be a transient effecton bodyweight in highdose males. The mean bodyweight <strong>of</strong> this groupdropped to below <strong>the</strong> pretreatment weight by approximately 5% at week 2and <strong>the</strong>n gradually increased to re-establish <strong>the</strong> pretreatment weight byweek 8. Mean bodyweight <strong>the</strong>n continued to steadily increase, reaching anequivalent bodyweight as <strong>the</strong> control group by week 20, despite having alower (~7%) pretreatment bodyweight than <strong>the</strong> control group. None <strong>of</strong> <strong>the</strong>sefindings appeared to be statistically significant. An examination <strong>of</strong>individual animal data revealed that <strong>the</strong> apparent effect on bodyweight inhigh-dose males was attributable to a single animal (#26237) which lostapproximately 15% <strong>of</strong> its pretreatment bodyweight over <strong>the</strong> first 3 weeks <strong>of</strong>dosing, and never completely recovered. This animal also exhibited <strong>the</strong>highest incidence <strong>of</strong> emesis over <strong>the</strong> dosing period (29 <strong>of</strong> <strong>the</strong> 38 incidents).There was no treatment-related effect on food consumption.Ophthalmoscopy: There were no ophthalmoscopic abnormalities that wereattributable to <strong>the</strong> test compound.Haematology, clinical chemistry and urinalysis: There was no treatmentrelatedeffect on any haematology, clinical chemistry or urinalysisparameter.Dichlorvos reassessment – application Page 233 <strong>of</strong> 436
ChE inhibition: There was a clear dose-related inhibition <strong>of</strong> plasma andRBC ChE activities. Toxicologically-significant inhibition <strong>of</strong> plasma andRBC (i.e. >20% inhibition relative to pretreatment activity) occurred at andabove 1.0 mg/kg b.w./day at every sampling interval. Statistical analysiswas only per<strong>for</strong>med on data from week 13. The magnitude <strong>of</strong> inhibition wasequivalent in males and females, ranging from 39-59% and 65-74% <strong>for</strong>plasma ChE inhibition at 1.0 and 3.0 mg/kg b.w./day, respectively, and 33-65% and 68-94% <strong>for</strong> RBC ChE inhibition at 1.0 and 3.0 mg/kg b.w./day,respectively. No cholinergic signs were evident at <strong>the</strong> highest dose evenwith <strong>the</strong> magnitude <strong>of</strong> RBC ChE inhibition (up to 94%). Results <strong>of</strong> brainChE activity measurements were not provided, although it was reported thatstatistical analysis revealed significant inhibition at and above 1.0 mg/kgb.w./day in males (p
BACKGROUND:The APVMA (2008a) also reported:―Wi<strong>the</strong>rup S, Stemmer KL & Pfitzer EA (1967) The effects exerted uponrats during a period <strong>of</strong> two years by <strong>the</strong> introduction <strong>of</strong> Vapona® insecticideinto <strong>the</strong>ir daily diets. No study or Report No. Lab/Sponsor: The KetteringLaboratory, Department <strong>of</strong> Environmental Health, College <strong>of</strong> Medicine,University <strong>of</strong> Cincinnati, Ohio, USA. Report date: 14th February 1967.―Materials and MethodsDichlorvos (Shell Chemical Co; batch No. unspecified; 93% purity) wasdiluted in ethanol, admixed in <strong>the</strong> diet (Purine Laboratory Chow) and fed toCD weanling rats (40/sex/group; unspecified strain; Charles River,Massachusetts, USA) at 0, 0.1, 1, 10, 100 or 500 ppm <strong>for</strong> 2 years(equivalent to 0, 0.005, 0.05, 0.5, 5 and 25 mg/kg bw/d[ay], respectively,using a dietary conversion factor <strong>of</strong> 20). Diets were prepared weekly.Composite samples collected at 2, 4 and 7 days after preparation were storedfrozen prior to analysis <strong>of</strong>f-site by an unspecified method (Residue analysisLaboratory, Agricultural Research Division, Shell Development Company,Modesto, Cali<strong>for</strong>nia, USA). Rats had been acclimatised <strong>for</strong> two weeks priorto <strong>the</strong> initiation <strong>of</strong> treatment and were randomly assigned to each group.Rats were housed 3/cage in a room maintained at 76±2°F.―Rats were observed daily <strong>for</strong> clinical signs. Bodyweights were recordedweekly <strong>for</strong> <strong>the</strong> first year and <strong>the</strong>n twice weekly <strong>for</strong> <strong>the</strong> second year. Foodconsumption was not measured. Five rats/sex/group were sacrificed byexsanguination after 6, 12 or 18 months, with all remaining survivorssacrificed at <strong>the</strong> end <strong>of</strong> <strong>the</strong> treatment period (24 months). All rats werenecropsied and examined <strong>for</strong> gross visceral abnormalities. The followingorgans were weighed: liver, heart, lungs, kidneys, spleen, brain, gonads,pituitary, adrenals, and thyroid. These same organs were histopathologicallyexamined in addition to sections <strong>of</strong> <strong>the</strong> CNS.―Blood and urine were sampled from 10 rats/group at 6, 12, 18 and 24months <strong>for</strong> analysis. The following haematology parameters were analysed:Hb, Hct, total and differential leukocyte count. The following clinicalchemistry parameters were analysed: protein, albumin/globulin (A/G) ratio,and plasma and RBC ChE activities. Plasma and RBC ChE activities werealso measured at regular intervals during <strong>the</strong> study (13 times). Brain ChEactivity was measured at each <strong>of</strong> <strong>the</strong> 4 sacrifice times. The followingurinalysis parameters were analysed: albumin, glucose, acetone, pH andmicroscopic analysis <strong>for</strong> cellular components, crystals <strong>of</strong> uric acid, calciumoxide and triphosphates, and <strong>for</strong> amorphous material.―Results“Dietary analysis: There was considerable loss <strong>of</strong> dichlorvos associatedwith a gradual increase in DCA [dichloroacetaldehyde]. At <strong>the</strong> 5 doseDichlorvos reassessment – application Page 235 <strong>of</strong> 436
levels, analytical dichlorvos concentrations were 0.08, 0.80, 8.0, 80 and 400ppm after 12 h[ours], declining to 0.022, 0.224, 2.24, 22 and 112 ppm after156 h[ours], respectively. Average concentrations <strong>of</strong> dichlorvos were 0.047,0.467, 4.67, 46.7 and 234 ppm. The average DCA content present was0.014, 0.114, 0.887, 6.86 and 28.6 ppm in <strong>the</strong>se groups, respectively.“Mortalities, clinical signs and bodyweight effects: There was no treatmentrelatedeffect on mortalities, clinical signs or bodyweight gain.“Haematology, clinical chemistry and urinalysis: There was no treatmentrelatedeffect on any heamatology, clinical chemistry or urinary parameter.ChE activity: Plasma and RBC ChE activities were measured 13 timesduring <strong>the</strong> study, with no significant effects observed in <strong>the</strong> three lowestdose groups. In <strong>the</strong> 100 ppm group, plasma and RBC ChE activities werereduced to 60-90% and to 50-90% <strong>of</strong> controls in males and females,respectively. In <strong>the</strong> 500 ppm group, activities were reduced to 20-70% and20-60%, respectively. Activities tended to increase as <strong>the</strong> study progressed.At termination, brain ChE activity was significantly decreased only in <strong>the</strong>500 ppm group, by 45-47% in rats sacrificed after 6 months, declining to 5-15% in those sacrificed after 24 months.“Pathology: There was no treatment-related effect on organ weights <strong>of</strong> ratssacrificed at scheduled intervals or at termination, and <strong>the</strong>re were notreatment-related macroscopic lesions. Histology revealed hepatocellularfatty vacuolisation in all 500 ppm rats, and in approximately 80% <strong>of</strong> femalesand 62% <strong>of</strong> males at 100 ppm. This was only evident in animals sacrificedafter 18 or 24 months. All neoplastic lesions were benign, with mostoccurring in <strong>the</strong> mammary and pituitary glands <strong>of</strong> both sexes without dosedependency.There were no tumours that occurred only at <strong>the</strong> high-dose.Overall, no treatment-related effects were observed on <strong>the</strong> incidence ortiming <strong>of</strong> tumours.“Conclusion: The NOEL following 2-years <strong>of</strong> dietary exposure todichlorvos was 10 ppm (mean analytical concentration <strong>of</strong> 4.67 ppm;equivalent to 0.23 mg/kg bw/d[ay]) based on <strong>the</strong> inhibition <strong>of</strong> plasma andRBC ChE activity at and above 100 ppm (mean analytical concentration46.7 ppm; equivalent to 2.3 mg/kg bw/d[ay]). Hepatocellular abnormalitieswere evident at 100 and 500 ppm, but <strong>the</strong>se were insufficient to indicateimpairment <strong>of</strong> normal liver function.‖ (Original not sighted; APVMA,2008a)The ATSDR (1997) reported:“In a 90-day study in female Sherman rats, groups <strong>of</strong> 10 animals wereexposed to doses ranging from 0 to 69.9 mg/kg [b.w.]/day in <strong>the</strong>ir feed(Durham et al. 1957). Two animals from each group were bled on days3, 11, 60, and 90, and serum cholinesterase and erythrocyteacetylcholinesterase were determined. Clinical signs <strong>of</strong> neurologicaltoxicity were not noted in any dosage group. Cholinesterase data waspresented graphically so <strong>the</strong> percentage inhibition <strong>of</strong> <strong>the</strong>Dichlorvos reassessment – application Page 236 <strong>of</strong> 436
cholinesterases can only be estimated. For serum cholinesterase, doses<strong>of</strong> 0.4 and 1.5 mg/kg [b.w.]/day appeared to have no effect. Doses <strong>of</strong> 3.5and 14.2 mg/kg [b.w.]/day appeared to produce 25-40% inhibition <strong>of</strong>enzyme activity compared to control values by <strong>the</strong> third day <strong>of</strong> feeding;activity remained depressed up to 60 days, and rose to near controlvalues by <strong>the</strong> end <strong>of</strong> <strong>the</strong> experiment at 90 days. Serum cholinesterase inrats consuming 35.7 and 69.9 mg/kg [b.w.]/day fell by 50% after 3 daysand remained at this level throughout <strong>the</strong> experiment. Erythrocyteacetylcholinesterase was unaffected at doses up to 3.5 mg/kg[b.w.]/day. Acetylcholinesterase activity was inhibited by 30% after 3days at 14.2 mg/kg [b.w.]/day and remained depressed until <strong>the</strong> end <strong>of</strong><strong>the</strong> experiment. At 35.7 and 69.9 mg/kg [b.w.]/day, erythrocyteacetylcholinesterase was inhibited about 50% after 3 days and 80%after 10 days. There appeared to be some recovery to about 50% <strong>of</strong>control by <strong>the</strong> end <strong>of</strong> <strong>the</strong> experiment. Female Fischer 344 rats treatedwith dichlorvos by oral gavage 5 days a week <strong>for</strong> up to 32 days had nosignificant changes in erythrocyte acetylcholinesterase activity at dosesup to 16 mg/kg [b.w.]/day (NTP 1989). Male rats at <strong>the</strong> same dosagelevels had a 22% decrease in erythrocyte acetylcholinesterase at day 24at 16 mg/kg [b.w.]/day.” (Originals not sighted; ATSDR, 1997)Dichlorvos reassessment – application Page 237 <strong>of</strong> 436
21 SPECIFIC TARGET ORGAN TOXICITY 6.9 (REPEAT DOSE – DERMAL)HSNO Classification: Specific target organ toxicity (Repeat dose – dermal) –Insufficient dataKEY STUDY: None• Justification:No studies adequate were reported.BACKGROUND:The ATSDR (1997) reported:“Three cynomolgus monkeys were exposed to dichlorvos dissolved inxylene by daily derrnal doses on a shaved area between <strong>the</strong> shoulderblades (Durham et al. 1957); cholinergic signs appeared within 10-20minutes <strong>of</strong> dosage. Signs <strong>of</strong> toxicity in order <strong>of</strong> appearance were:nervousness, incoordination, muscle fasciculations, excessive salivation,labored breathing, miosis, and inability to move. The authors stated thatat a given dose, <strong>the</strong> cholinergic signs tended to become more severewith subsequent doses. Serum cholinesterase and erythrocyteacetylcholinesterase were measured in one monkey that received 75mg/kg [b.w.]/day. After 2 doses, erythrocyte acetylcholinesterase haddeclined about 67%, while serum cholinesterase was unchanged. When<strong>the</strong>se values were measured shortly after <strong>the</strong> next day’s dosage, <strong>the</strong>serum cholinesterase had fallen about 33%, while erythrocyteacetylcholinesterase remained inhibited about 67%. The serumcholinesterase recovered after 2 days without dosing, but <strong>the</strong>erythrocyte acetylcholinesterase did not. After 5 doses, <strong>the</strong> erythrocyteacetylcholinesterase had fallen by 90% and stayed <strong>the</strong>re until deathoccurred after 12 days, during which 10 doses were administered.”(Originals not sighted; ATSDR, 1997)Dichlorvos reassessment – application Page 238 <strong>of</strong> 436
22 SPECIFIC TARGET ORGAN TOXICITY 6.9 (REPEAT DOSE – INHALATION)HSNO Classification: Specific target organ toxicity (Repeat dose –inhalation) – 6.9AKEY STUDY:• Type <strong>of</strong> study:• Species:Chronic (2-year) Inhalation in Rodents;Rat;• Strain: Carworth Farm E;• Sex/Numbers:50/sex/group;• Test material: Dichlorvos (Batch No: unspecified; >97%);• Dose levels: Air concentrations <strong>of</strong> 0, 0.05, 0.5 or 5 mg/m 3 <strong>for</strong> 23hours/day <strong>for</strong> 2 years. Achieved mean concentrations were0, 0.05, 0.48 and 4.70 mg/m 3 , respectively. Trimethylphosphate was also present at 0, 0.007 and 0.04 mg/m 3 in<strong>the</strong> low-, mid- and high-dose atmospheres, respectively, aswas dichloroacetaldehyde (DCA) at 0.007, 0.013 and0.028 mg/m 3 ;• Endpoint:Clinical signs, mortality, body weight gain, foodconsumption, clinical chemistry, haematology or urinaryparameters, organ weight, gross/microscopic abnormalitiesand tumour incidences; plasma, RBC and brain AChEactivities;• Remarks:Mortalities, Clinical Signs and Effects on Bodyweight and FoodConsumption: The average weekly concentrations <strong>of</strong> dichlorvos in testatmospheres were reasonably consistent and close to nominal throughout <strong>the</strong>treatment period. Mortality was highest in control groups and lowest inhigh-dose groups. Survival rates <strong>of</strong> 22, 42, 30 and 64% in males, and 50, 60,58 and 76% in females recorded in control, low-, mid- and high-dosegroups, respectively. The highest morbidity rate in controls occurred fromapproximately 75 weeks. The low survival in controls caused <strong>the</strong> earlycessation <strong>of</strong> treatment in males during week 99; female treatment continuedto week 104. There were no adverse clinical signs indicative <strong>of</strong> OPpoisoning but some rats, generally males, showed lameness and ulceratedhocks (probably related to <strong>the</strong> wire floor <strong>of</strong> <strong>the</strong> cage). The only lesion notedin treated but not control groups was a sore tail, <strong>of</strong>ten with necrosis <strong>of</strong> <strong>the</strong>tip, seen in 2 highdose males and 12 high-dose females. Body weight gainwas slightly though significantly reduced (p
odyweight depressed by 10-13% (only significant in males). Foodconsumption was unaffected by treatment.Clinical chemistry: At termination <strong>the</strong>re was a slight though significantincrease (p
Ltd, Sittingbourne Research Center, UK. Report date: June1974.Blair D, Dix KM, Hunt PF, Thorpe E, Stevenson DE &Walker AIT (1976) ―Dichlorvos - a 2-year inhalationcarcinogenesis study in rats.‖ Arch. Toxicol. 35: 281-294.(Original not sighted; APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Classification: Blair et al. (1974 & 1976) were not conducted to GLPor Test Guideline. The LOAEL (= 0.5 mg/m 3 ) is below <strong>the</strong> threshold <strong>for</strong> 6.9Aclassification as a mist <strong>for</strong> repeat dose exposures in Table 17.2 <strong>of</strong> <strong>the</strong> User Guide to<strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act (ERMA, 2008). [0.5 mg/m 3 isconverted to 0.0005 mg/L, so is well below <strong>the</strong> threshold <strong>of</strong> 0.5 mg/L <strong>for</strong> 6.9A as amist.]BACKGROUND:The ATSDR (1997) reported:“Hematological Effects. Hematological parameters (hemoglobinconcentration, erythrocyte numbers, total and differential leucocytenumbers, prothrombin time, and kaolin-cephalin coagulation time) <strong>for</strong> ratsexposed to atmospheres containing up to 5 mg dichlorvos/m 3 (0.6 ppm) <strong>for</strong>2 years were not significantly different from controls (Blair et al. 1976).“Hepatic Effects. Increased serum levels <strong>of</strong> serum glutamic oxaloacetictransaminase (SGOT, now identified as aspartate aminotransferase [AST])and serum glutamic pyruvic transaminase (SGPT, now identified as alanineaminotransferase [ALT]), possibly indicating hepatic damage, wereobserved in male Carworth E rats exposed to 5 mg dichlorvos/m 3 (0.6 ppm)in a 2-year inhalation study (Blair et al. 1976). No changes in SGOT orSGPT were reported in rats <strong>of</strong> ei<strong>the</strong>r sex exposed to 0.06 ppm dichlorvos.“Body Weight Effects. The body weight <strong>of</strong> male Cat-worth E rats exposedto atmospheres containing 5 mg dichlorvos/m 3 (0.6 ppm) <strong>for</strong> 2 years wasconsistently 20% or more below <strong>the</strong> body weight <strong>of</strong> control rats from <strong>the</strong>tenth week <strong>of</strong> treatment (Blair et al. 1976). Body weights <strong>of</strong> female ratsexposed <strong>under</strong> <strong>the</strong> same conditions were not significantly different fromcontrols.“Metabolic Effects. Decreased serum chloride was reported in maleCarworth E rats exposed to 5 mg/m 3 dichlorvos (0.6 ppm) in a 2-yearinhalation study (Blair et al. 1976). The magnitude <strong>of</strong> this decrease was notreported. No changes in serum chloride were reported in rats <strong>of</strong> ei<strong>the</strong>r sexexposed to 0.06 ppm dichlorvos.Immunological and Lymphoreticular EffectsDichlorvos reassessment – application Page 241 <strong>of</strong> 436
― … Total and differential leucocyte numbers were unchanged compared tocontrols in Carworth E rats exposed to atmospheres containing up to 5mg/m 3 (0.6 ppm) <strong>for</strong> 2 years (Blair et al. 1976).Neurological Effects“Several studies in animals have addressed neurological effects afterintermediate-duration inhalation exposure to dichlorvos. In a study <strong>of</strong>pregnant Carworth E rats exposed over <strong>the</strong>ir gestation period (20days), some dams exposed to atmospheres containing 6.25 mg/m 3(0.69 ppm) were less active than controls (Thorpe et al. 1972).Exposure at 0.25 mg/m 3 (0.03 ppm) did not affect erythrocyte or brainacetylcholinesterase. Exposure at 1.25 mg/m 3 (0.14 ppm) resulted in a29% inhibition <strong>of</strong> erythrocyte and a 28% inhibition <strong>of</strong> brainacetylcholinesterase, while exposure at 6.25 mg/m 3 resulted in 88%inhibition <strong>of</strong> erythrocyte acetylcholinesterase and an 83% inhibition <strong>of</strong>brain acetylcholinesterase. In <strong>the</strong> same exposure atmosphere, pregnantDutch rabbits showed inhibition <strong>of</strong> 14 and 10% in erythrocyte andbrain acetylcholinesterase, respectively, at an exposure <strong>of</strong> 0.25 mg/m 3(0.03 ppm) over a period <strong>of</strong> 28 days (Thorpe et al. 1972). At exposures<strong>of</strong> 1.25 mg/m 3 (0.14 ppm) erythrocyte acetylcholinesterase wasinhibited 68% and brain acetylcholinesterase was inhibited 56%compared to controls. Exposure <strong>of</strong> Yorkshire pigs <strong>for</strong> 24 days toatmospheres containing 0.09-0.11 mg/m3 (0.010-0.012 ppm) had noeffect on serum cholinesterase or erythrocyte acetylcholinesterase(Loeffler et al. 1976).” (Originals not sighted; ATSDR, 1997)Dichlorvos reassessment – application Page 242 <strong>of</strong> 436
23 OTHER POTENTIAL TOXIC ENDPOINTS23.1 Endocrine Disruption:The APVMA (2008a), ATSDR (1997), US EPA (2006) and WHO (1988 & 1993)reviews did not address endocrine disruption directly. However, <strong>the</strong> reportedreproductive and development studies gave no indication <strong>of</strong> specific endocrinedisruptive effects. The toxicology pr<strong>of</strong>ile <strong>of</strong> dichlorvos was dominated by neurotoxiceffects.The ATSDR 1997) reported:“Cytoplasmic vacuolization <strong>of</strong> adrenal cortical cells was noted in maleFischer 344 rats receiving 4 or 8 mg/kg [b.w.]/day dichlorvos by gavage<strong>for</strong> 5 days a week <strong>for</strong> 2 years (NTP 1989). The authors stated that <strong>the</strong>sechanges were minor in extent but have been associated with lipidaccumulation in cells. Significant neoplastic lesions <strong>of</strong> <strong>the</strong> pancreas(adenomas) were also observed in <strong>the</strong> male rats. No increase in lesionswas observed <strong>for</strong> male or female rats in <strong>the</strong> parathyroid, pituitary,thyroid or thymus glands. No treatment-related lesions were observed<strong>for</strong> any endocrine tissue in B6C3FI mice treated <strong>for</strong> 2 years at 20 mg/kg[b.w.]/day (males) or 40 mg/kg [b.w.]/day (females) (NTP 1989) or inBeagle dogs (groups <strong>of</strong> 4 <strong>of</strong> each sex) receiving up to 3 mg/kg/day bycapsule <strong>for</strong> 52 weeks (AMVAC Chemical Corp. 1990).” (Originals notsighted; ATSDR, 1997)US EPA Endocrine Disruptor Screening Program (EDSP)The US EPA has published <strong>the</strong> final list <strong>of</strong> <strong>the</strong> first group <strong>of</strong> pesticide active ingredientsand High Production Volume (HPV) chemicals <strong>for</strong> testing <strong>for</strong> hormonal effects (FederalRegister / Vol. 74, No. 71 / Wednesday, April 15, 2009 / Notices). The selection <strong>of</strong> <strong>the</strong>chemicals was based on exposure potential (greater potential <strong>for</strong> exposure, greaterlikelihood <strong>for</strong> inclusion in <strong>the</strong> first list). The US EPA noted that ―it [<strong>the</strong> first selection]should not be construed as a list <strong>of</strong> known or likely endocrine disruptors‖. In relation todichlorvos, it has been removed from <strong>the</strong> list <strong>of</strong> substances to be reviewed with <strong>the</strong>following conclusion:―The initial analysis using <strong>the</strong> exposure based criteria <strong>for</strong> chemical selectionfound dichlorvos in three exposure pathways: Food, residential, and occupational.There are currently no registered uses <strong>of</strong> dichlorvos that will result in occupationalexposure pathways associated with <strong>the</strong> selected 14 work activities/crop categorieshaving <strong>the</strong> highest transfer coefficients. Dichlorvos is only present in twoexposure pathways (food and residential) and will not be tested at this time.‖Source: http://www.epa.gov/endo/pubs/final_list_frn_041509.pdfThe exclusion <strong>of</strong> dichlorvos by <strong>the</strong> US EPA from <strong>the</strong> first list <strong>of</strong> chemicals <strong>for</strong> screening<strong>under</strong> <strong>the</strong> EDSP gives no guidance on <strong>the</strong> inherent potential <strong>of</strong> dichlorvos to causehormonal effects, as <strong>the</strong> exclusion was solely based on exposure potential.23.2 Neurotoxicity:Dichlorvos reassessment – application Page 243 <strong>of</strong> 436
[See earlier Sections <strong>for</strong> Key Studies with neurotoxicological end-points.]Dichlorvos exerts toxicity by inhibition <strong>of</strong> plasma, RBC and brain ChE activities, as <strong>the</strong>most sensitive end-points, and as a result is neurotoxic. However, studies indicate thatdichlorvos does not induce organophosphate-induced delayed neurotoxicity (OPIDN) inhen or rat.The APVMA (2008a) reported:―Dose-related inhibition <strong>of</strong> plasma, RBC and brain ChE activities was <strong>the</strong>most common manifestation <strong>of</strong> dichlorvos toxicity in short-term, subchronicand chronic studies in mice, rats and dogs. Cholinergic signs and occasionalmortalities occurred in rats and dogs at <strong>the</strong> same doses as <strong>the</strong> inhibition <strong>of</strong>brain ChE activity. Plasma and RBC ChE activities were also inhibitedfollowing chronic inhalational exposure in rats (LOEC = 0.5 mg/m 3 ; Blair etal 1974 & 1976).―Dichlorvos is acutely neurotoxic in chickens and rats by virtue <strong>of</strong> its abilityto inhibit brain ChE activity (Beavers 1988; Lamb 1993a). This is typifiedby <strong>the</strong> occurrence <strong>of</strong> cholinergic signs and abnormal FOB (rats) followingsingle or repeated oral dosing. There was no evidence that dichlorvos causesdelayed neuropathy (Beavers 1988; Redgrave et al 1994a & b, Redgrave &Mansell 1994, Jortner 1994 and Hardisty 1998; Lamb 1993b).‖ (Originalsnot sighted; APVMA, 2008a)[See Section 17: Specific target organ toxicity (Single dose – oral) <strong>for</strong> Lamb (1993a &1993b).]―Beavers J, Driscoll CP, Dukes V & Jaber M (1988) DDVP: An acutedelayed neurotoxic study in chickens. Wildlife International Ltd Project No.246-103. Lab: Wildlife International Ltd, Easton, Maryland, USA. Sponsor:AMVAC Chemical Corporation, Los Angeles, Cali<strong>for</strong>nia, USA. Studyduration: 8th August 1988 to 20th September 1988. Report date: 29thDecember 1988.―GLP compliant (US EPA; 40 CFR Part 160) and QA study. Study based inpart on Section 81-7 <strong>of</strong> US EPA/OPP Pesticide Guidelines (Subdivision F,EPA 540/9-82-025, November 1982).“Materials and MethodsA single oral gavage dose <strong>of</strong> dichlorvos (AMVAC Chemical Corporation,Los Angeles, CA, USA; lot No. 802097; 96.5% purity) was administered to10 fasted domestic chickens/group (42 weeks old; 1214-1688 g bw; TruslowFarms Inc, Chestertown, Maryland, USA) at 0 or 16.5 mg/kg bw in distilledwater. A positive control group was administered a single oral gavage dose<strong>of</strong> 600 mg/kg bw tri-ortho cresyl phosphate (TOCP) in corn oil. After 21days, all positive control birds were sacrificed, while <strong>the</strong> negative controland dichlorvos groups were redosed (after a minimum <strong>of</strong> 15 hours fasting)and observed <strong>for</strong> a fur<strong>the</strong>r 21 days.Dichlorvos reassessment – application Page 244 <strong>of</strong> 436
―Results“Mortalities and clinical signs: There were no mortalities in any group.Dichlorvos-treated birds exhibited cholinergic signs (lethargy or depression,incoordination, lower limb weakness, wing droop, reduced reaction toexternal stimuli, a ruffled appearance, prostrate posture and a loss <strong>of</strong>righting reflex) from approximately 30 min after dosing. Birds <strong>the</strong>nrecovered over <strong>the</strong> 21-day observation period. Following <strong>the</strong> second dose (atday 22), similar clinical signs were observed. Two TOCP-treated birdsexhibited transient incoordination or lower limb weakness at day 0, with athird bird exhibiting <strong>the</strong> same clinical signs over an extended period <strong>of</strong> time.By terminal sacrifice on day 21, all TOCP-treated birds exhibitedincoordination and lower limb weakness.“Locomotor activity: One animal from <strong>the</strong> control group (#1768) showedlocomotor abnormalities at days 7 (incoordination, pronounced ataxia) and10 (incoordination). Two separate birds refused to hop or walk at day 25,but were not ataxic. Three birds from <strong>the</strong> dichlorvos group showedlocomotor abnormalities over <strong>the</strong> first 10 days <strong>of</strong> dosing; at day 3 (#G30,G37; slight to moderate ataxia), 7 (#G37; slight ataxia) and 10 (#G36; slightlameness). Two birds from <strong>the</strong> TOCP group (#R254, R255) showedlocomotor abnormalities (slight-moderate ataxia) on day 3 and 7,respectively. However, <strong>the</strong> most obvious effect on this group occurred atday 21 when 6/10 birds exhibited abnormal locomotory activity rangingfrom slight to pronounced ataxia. This finding was clearly treatment-relatedand indicated that <strong>the</strong> positive control did in fact cause delayedneurotoxicity.“Histopathology: No control birds displayed any microscopic abnormalities<strong>of</strong> <strong>the</strong> brain, spinal cord or bilateral peripheral nerve, while one bird treatedwith dichlorvos (#G37) exhibited sciatic neural degenerative changes(described as swelling <strong>of</strong> <strong>the</strong> axis cylinder and nerve fibre degeneration). Incontrast, treatment with <strong>the</strong> positive control (TOCP) resulted in 5/10 birdswith degeneration <strong>of</strong> <strong>the</strong> sciatic nerve, particularly <strong>the</strong> distal segments. Thedegeneration included swelling <strong>of</strong> <strong>the</strong> axis cylinder, nerve fibredegeneration and Schwann cell proliferation. It is somewhat difficult todismiss <strong>the</strong> sciatic nerve degeneration in <strong>the</strong> single bird in <strong>the</strong> dichlorvosgroup since <strong>the</strong> finding was qualitatively <strong>the</strong> same as <strong>the</strong> positive controland no such findings occurred in <strong>the</strong> negative controls. An examination <strong>of</strong>individual bird data <strong>for</strong> <strong>the</strong> positive control group did not reveal a strongcorrelation between abnormal locomotor activity and sciatic nervedegeneration. In fact, 2/5 birds that exhibited nerve degeneration showed nolocomotor effects, while 3/5 birds that showed no degeneration displayedabnormal locomotor activity. In <strong>the</strong> absence <strong>of</strong> historical control data, <strong>the</strong>occurrence <strong>of</strong> neural degenerative changes in <strong>the</strong> single dichlorvos-treatedhen was considered by <strong>the</strong> reviewing toxicologist to be <strong>of</strong> equivocalrelationship to treatment.Dichlorvos reassessment – application Page 245 <strong>of</strong> 436
“Conclusions: A single oral dose <strong>of</strong> 16.5 mg/kg bw dichlorvos resulted incholinergic signs and significantly reduced food consumption.Histopathological examination revealed sciatic nerve degeneration in onehen in <strong>the</strong> absence <strong>of</strong> any clinical signs <strong>of</strong> delayed neurotoxicity. It wasequivocal whe<strong>the</strong>r this finding was attributable to dichlorvos treatment.Deficiencies noted in this study were <strong>the</strong> absence <strong>of</strong> statistical analysis andmacroscopic examination. Fur<strong>the</strong>rmore, no biochemical analysis wasper<strong>for</strong>med on any birds, such as <strong>the</strong> measurement <strong>of</strong> neuropathy targetesterase (NTE) or brain ChE activity.‖ (Originals not sighted; APVMA,2008a)―Redgrave VA, Mansell P, Crook D, Begg, SE, Gopinath C, Anderson A &Dawe IS (1994a) DDVP: 28-day neurotoxicity study in <strong>the</strong> domestic hen.Study No. AVC 1/921405. Lab: Huntingdon Research Centre Ltd,Huntingdon, Cambridgeshire, England. Sponsor: AMVAC ChemicalCorporation, Los Angeles, Cali<strong>for</strong>nia, USA. Study duration: 28th April1992 to 3rd February 1994. Report date: 21 st October 1994.―Redgrave VA & Mansell P (1994) TOCP: Supplementary data on <strong>the</strong>delayed neurotoxicity to <strong>the</strong> domestic hen. Study No. AVC 1a/931884.Sponsor: Huntingdon Research Centre Ltd, Huntingdon, Cambridgeshire,England. Sponsor: AMVAC Chemical Corporation, Los Angeles,Cali<strong>for</strong>nia, USA. Study duration: 14th April 1993 to 22nd July 1994. Reportdate: 17th February 1994.―Redgrave VA, Cameron DM, Gopinath C & Dawe IS (1994b) TOCP: 28-day neurotoxicity in <strong>the</strong> domestic hen. Study No. RAD 2/942053. Sponsor:Huntingdon Research Centre Ltd, Huntingdon, Cambridgeshire, England.Sponsor: AMVAC Chemical Corporation, Los Angeles, Cali<strong>for</strong>nia, USA.Study duration: 16th November 1993 to 4th February 1994. Report date:21st October 1994.―Jortner B (1994) Neuropathological review <strong>of</strong> studies AVC/1 and RAD/2,Huntingdom Research Centre. Report No. unspecified. Sponsor: AMVACChemical Corporation, Los Angeles, Cali<strong>for</strong>nia, USA. Report date:September 1994.―Hardisty JF (1998) Pathology working group peer review <strong>of</strong> DDVP 28-dayneurotoxicity study in <strong>the</strong> domestic hen. EPL Project No. 578-001. Lab:Experimental Pathology Laboratories Inc, Research Triangle Park, NC,USA. Sponsor: AMVAC Chemical Corporation, Los Angeles, Cali<strong>for</strong>nia,USA. Report date: 2nd April 1998.―GLP compliant (UK Compliance Programme, Dept Health & SocialSecurity 1986 and subsequent revision, Dept Health 1989; EC CouncilDirective 87/18 EEC <strong>of</strong> 19 December 1986, No. L 15/29; GLP in <strong>the</strong> testing<strong>of</strong> Chemicals OECD, ISBN 92-64-12367-9, Paris 1982, subsequentlyrepublished OECD Environment Monograph No. 45, 1992; US EPA; 40CFR Part 160; Japanese Ministry <strong>of</strong> Agriculture, Forestry and Fisheries, 59NohSan, Notification No. 3850, Agricultural Product Bureau, 10th AugustDichlorvos reassessment – application Page 246 <strong>of</strong> 436
1984). QA study. Study conducted according to US EPA PesticideAssessment Guidelines, Subdivision F, Hazard Evaluation: Human andDomestic Animals, Addendum 10: Neurotoxicity Series 81, 82 and 83,dated March 1991.―Materials and Methods―Dichlorvos (AMVAC Chemical Corporation, Los Angeles, CA, USA; lotNo. 802097; 97.87% purity) was administered orally by gavage to 12 adultfemale domestic hens per group (approximately 12-months old; 1945-2295g bw; Atkinson Bros, Postland, Crowland, Peterborough, Cambridgeshire,England) at 0, 0.3, 1.0 or 3.0 mg/kg bw/d[ay] in distilled water <strong>for</strong> 28 days.An additional group <strong>of</strong> 3 birds was administered 0.1 mg/kg bw/d[ay]dichlorvos <strong>for</strong> measurement <strong>of</strong> brain ChE activity. A positive control groupwas administered a daily oral gavage dose <strong>of</strong> 7.5 mg/kg bw/d[ay] TOCP(Coalite Chemical Group, location unspecified; Batch No. S16848; assumed100% purity) in corn oil <strong>for</strong> 28 days.―Results“Mortalities, clinical signs: One bird from <strong>the</strong> 1.0 mg/kg bw/d[ay] groupand 4 birds from <strong>the</strong> 3.0 mg/kg bw/d[ay] group died during or immediatelyafter <strong>the</strong> 28-day dosing period. Pretreatment mortalities in o<strong>the</strong>r groups(including <strong>the</strong> control) were due to aggression. Treatment-related clinicalsigns were observed at 1.0 and 3.0 mg/kg bw/d[ay] dichlorvos, but did notoccur in any o<strong>the</strong>r groups (including <strong>the</strong> positive control). At 1.0 mg/kgbw/d[ay], only 2/21 birds exhibited clinical signs, which included aninability to stand and unsteadiness. At 3.0 mg/kg bw/d[ay], 19/21 birds werequiet or subdued and unsteady. These clinical signs were observed 30 minafter dosing and were reported to last <strong>for</strong> up to 8 hours. By day 30, allsurviving birds appeared normal.“Delayed locomotor ataxia: It was reported that <strong>the</strong>re were no clinical signs<strong>of</strong> neurotoxicity and no evidence <strong>of</strong> delayed locomotor ataxia in any bird.However, <strong>the</strong> results <strong>of</strong> <strong>the</strong> assessment <strong>of</strong> ataxia were not provided,including results <strong>for</strong> <strong>the</strong> positive control.“Brain ChE activity: There was dose-related inhibition <strong>of</strong> brain ChEactivity, which was toxicologically significant (ie. >20% relative to <strong>the</strong>control) at and above 1.0 mg/kg bw/d[ay] at day 4, and at and above 0.3mg/kg bw/d at day 30. No statistical analysis was per<strong>for</strong>med on this data.“NTE activity: There was no treatment-related effect on ei<strong>the</strong>r brain orspinal cord NTE activity. [Neuropathy target esterase (NTE); Inhibition <strong>of</strong>this particular enzyme is a marker <strong>for</strong> predicting delayed neurotoxicity fromorganophosphate pesticides. (Handbook <strong>of</strong> Pesticide Toxicology, Ed RKrieger, 2001, Academic Press, San Diego CA. USA, Vol 2 p953ff.)] Incontrast, <strong>the</strong> positive control (7.5 mg/kg bw/d[ay] TOCP) caused a markedreduction in both brain and spinal cord NTE activity relative to <strong>the</strong> negativecontrol at day 4 and 30. No statistical analysis was per<strong>for</strong>med on this data.Dichlorvos reassessment – application Page 247 <strong>of</strong> 436
“Necropsy: Macroscopic examination <strong>of</strong> deceased hens and those sacrificedat days 49 and 77 revealed no abnormalities that could be attributed todichlorvos.“Histopathology: At days 49 and 77, TOCP-treated birds (5/6) showedaxonal degeneration in <strong>the</strong> cerebellum ranging from a trace to minimal,while <strong>the</strong>re were no treatment-related abnormalities in <strong>the</strong> cerebellum <strong>of</strong> anyo<strong>the</strong>r group. Relative to <strong>the</strong> negative control, <strong>the</strong>re was an increasedincidence <strong>of</strong> axonal degeneration in <strong>the</strong> lower cervical and lumbo-sacralspinal cord <strong>of</strong> dichlorvos-treated birds, but this did not follow a doseresponserelationship and was generally graded as ―trace‖. According to <strong>the</strong>grading system used by <strong>the</strong> study authors, a grading <strong>of</strong> ―trace‖ is notconsidered as biologically significant. There<strong>for</strong>e, <strong>the</strong> majority <strong>of</strong> <strong>the</strong>sefindings can be disregarded as treatment-related. However, it should benoted that 1/6 and 2/6 dichlorvos-treated birds sacrificed at day 49 werescored as having minimal axonal degeneration in <strong>the</strong> upper cervical spinalcord, respectively, compared to 0/6 in <strong>the</strong> negative control group. Singlebirds in <strong>the</strong>se groups were also graded as having minimal axonaldegeneration in <strong>the</strong> upper cervical spinal cord at day 77, and in <strong>the</strong> lowercervical region at days 49 and/or 77. While <strong>the</strong>se incidences are slightlyhigher than <strong>the</strong> per<strong>for</strong>ming laboratories historical control range <strong>of</strong> 0-10%,<strong>the</strong> reviewing toxicologist did not consider that <strong>the</strong>y were treatment-related.―Neuropathological findings from <strong>the</strong> current study, as well as those from asupplementary study (No. RAD 2/942053, see below), were reviewed byJortner (1994) at <strong>the</strong> request <strong>of</strong> AMVAC. This review involved a reevaluation<strong>of</strong> <strong>the</strong> histopathology slides <strong>for</strong> each animal. There was nodifference in <strong>the</strong> types and severity <strong>of</strong> lesions in <strong>the</strong> spinal cord <strong>of</strong> negativecontrol and dichlorvos-treated birds across all dose levels. In contrast, birdstreated with 15 or 20 mg/kg bw/d[ay] TOCP (Study No. RAD 2/942053)exhibited moderate to marked fibre degeneration in <strong>the</strong> spinal cord. Jortnerconcluded that dichlorvos does not cause OP-induced delayed neuropathy(OPIDN). Histopathology slides were re-examined again in 1998 by apathology working group convened by <strong>the</strong> sponsor (EPL Project N578-001).This working group confirmed <strong>the</strong> previous findings and conclusions.“Conclusions: The NOEL in hens following 28-days <strong>of</strong> repeated oral dosingwas 0.1 mg/kg bw/d[ay], based on <strong>the</strong> occurrence <strong>of</strong> toxicologicallysignificantinhibition <strong>of</strong> brain ChE activity at and above 0.3 mg/kgbw/d[ay]. Cholinergic signs occurred at and above 1.0 mg/kg bw/d[ay].There was no evidence that dichlorvos caused delayed neurotoxicity. Theabsence <strong>of</strong> statistical analysis and results <strong>of</strong> <strong>the</strong> locomotor assessment weredeficiencies <strong>of</strong> this study.‖ (Originals not sighted; APVMA, 2008a)23.3 Immunotoxicity:The ATSDR (1997) reported:Dichlorvos reassessment – application Page 248 <strong>of</strong> 436
“No in<strong>for</strong>mation was located on immunotoxicity in humans afterdichlorvos exposure. Only a few studies were located that addressedimmunotoxicity in animals after dichlorvos exposure.Immunosuppression after oral exposure to dichlorvos in rabbits hasbeen reported in three studies (Casale et al. 1983; Desi et al. 1978,1980). A dose-related suppression <strong>of</strong> <strong>the</strong> humoral immune responseinduced by S. typhimurium was observed in rabbits (Desi et al. 1978).A single oral dose <strong>of</strong> 120 mg/kg [b.w.] dichlorvos in male C57B l/6 micethat had been inoculated with sheep erythrocytes 2 days earliersuppressed <strong>the</strong> primary IgM response observed 48 hours later (Casaleet al. 1983). Severe signs <strong>of</strong> dichlorvos neurotoxicity were noted, and<strong>the</strong> authors stated that <strong>the</strong> immunosuppression observed in this studymay have been mediated indirectly by toxic chemical stress. It isunknown if <strong>the</strong> immune suppression noted after dichlorvos exposure in<strong>the</strong>se studies is secondary to cholinergic stimulation. Immunotoxicitystudies employing atropine prophylaxis to counteract <strong>the</strong>anticholinesterase effect <strong>of</strong> dichlorvos are necessary to resolve thisquestion. Additional studies examining potential longer-term effects <strong>of</strong>dichlorvos on <strong>the</strong> immune system by all three routes as well as shorttermeffects by <strong>the</strong> inhalation and dermal routes would be important<strong>for</strong> estimating human susceptibility <strong>for</strong> populations exposed <strong>for</strong> varyinglengths <strong>of</strong> time at hazardous waste sites.” (Originals not sighted;ATSDR, 1997)WHO (1988) also reviewed Desi et al. 1978, 1980.Dichlorvos reassessment – application Page 249 <strong>of</strong> 436
24 HUMAN EXPOSURE REPORTSThe APVMA (2008b) reported:―Hayes (1982) has described several cases <strong>of</strong> accidental occupationalpoisoning with dichlorvos. Two workers died after splashing a concentrated<strong>for</strong>mulation on <strong>the</strong>ir bare arms and failing to wash it <strong>of</strong>f promptly. In aserious but non-fatal case following dermal exposure, <strong>the</strong> victim developedslurred speech and drowsiness slightly more than 1.5 hours after <strong>the</strong>accident. He collapsed suddenly after reaching a hospital but was saved byadministration <strong>of</strong> oxygen, artificial respiration, 15 mg atropine sulfate(mostly iv) and o<strong>the</strong>r supportive treatment. Spillage <strong>of</strong> a 3% dichlorvossolution in oil onto a man‘s lap resulted in severe poisoning. There was noef<strong>for</strong>t to remove <strong>the</strong> poison <strong>for</strong> about 30 minutes after <strong>the</strong> accident, when asuperficial wash was per<strong>for</strong>med, followed by a bath at 90 minutespostexposure. The estimated dose <strong>of</strong> dichlorvos in this incident was 72mg/kg bw. In ano<strong>the</strong>r case, a man spilled a smaller amount <strong>of</strong> <strong>the</strong> sameproduct onto his arm. He removed his shirt immediately and washed withsoap and water about 15 minutes later, but developed dizziness and nausea.“Bisby JA & Simpson GR (1975) An unusual presentation <strong>of</strong> systemicorganophosphate poisoning. Med J Australia 2; 394 – 395.A PCO was accidentally exposed to dichlorvos (1% solution in mineralspirit) whilst using a gasoline engine-powered knapsack mister. He wasfumigating a commercial premises and was wearing a singlet and overallsand a cartridge-type respirator. After 10 minutes he noticed a leak onto hisleft shoulder from a faulty seal and changed his overalls, but not<strong>under</strong>garments, and placed a plastic sheet <strong>under</strong> <strong>the</strong> sprayer. During <strong>the</strong> day,he noticed increasing local irritation and burning in <strong>the</strong> contaminated skinarea. By <strong>the</strong> end <strong>of</strong> <strong>the</strong> shift he reported excessive tiredness, weakness,dizziness and breathing difficulties. After showering, <strong>the</strong> symptomsimproved although rapid shallow breathing lasted <strong>for</strong> 2 hours. He developedskin irritation, consisting <strong>of</strong> extensive areas <strong>of</strong> ery<strong>the</strong>ma and bulla. Whenwhole blood ChE was measured 3 days after exposure, it was 36% <strong>of</strong>normal but reached 51% after 5 days and 78% after a month.“Mathias CGT (1983) Persistent contact dermatitis from <strong>the</strong> insecticidedichlorvos. Contact Dermatitis 9; 217 – 218.A truck driver was exposed dermally to a liquid product containing 5%dichlorvos in 15% petroleum distillate and 80% trichloroethane, whichbecame spilled in vehicle. The next day he awoke with dermatitis <strong>of</strong> hisneck, anterior chest, dorsal hands and <strong>for</strong>earms. He also experienced afrontal headache, mild rhinorrhea, burning <strong>of</strong> <strong>the</strong> tongue and a bitter taste inhis mouth. Initial blood ChE activity level was in <strong>the</strong> ―low normal range‖. Arepeat assay 2 weeks later revealed activity in <strong>the</strong> ―high normal range‖. Thedermatitis resolved approximately 10 weeks after onset. Patch tests withdichlorvos in petrolatum were negative, so <strong>the</strong> cause <strong>of</strong> irritation waspresumed to be irritation ra<strong>the</strong>r than sensitisation.Dichlorvos reassessment – application Page 250 <strong>of</strong> 436
“Comment: These incidents clearly illustrate <strong>the</strong> potential <strong>for</strong> dichlorvos tocause toxicity via <strong>the</strong> dermal route. Dermal absorption may have beenenhanced by <strong>the</strong> mineral spirits/organic solvents in which <strong>the</strong> dichlorvoswas diluted. Given that dichlorvos is a slight skin irritant and was present atonly 1 or 5%, <strong>the</strong> dermal reactions were probably caused by <strong>the</strong> solvents.‖(Originals not sighted; APVMA, 2008b)The APVMA (2008a) also reported:In ATSDR (1997):―Gold RE & Holcslaw (1984) Dermal and respiratory exposure <strong>of</strong>applicators and residents to dichlorvos-treated residences. In: Dermalexposure related to pesticide use: discussion <strong>of</strong> risk assessment (RCHoneycutt, G Zwerg & N Ragsdoleet eds). American chemical SocietySymposum Series No. 273.―Materials and Methods―Two applicators were monitored <strong>for</strong> <strong>the</strong>ir exposure to dichlorvos during <strong>the</strong>treatment <strong>of</strong> twenty singlefamily residences with a 0.5% water-emulsionspray prepared from Vaponite 2EC (unspecified source and batch/lot No.;24.7%). The application rate was 0.19 g/m 2 dichlorvos (38.7 mL/m 2 spray)and <strong>the</strong> average residence size was 103±33 m 2 . Temperature and humiditywere 26.1°C and 82%, respectively. The spray was applied along <strong>the</strong>baseboards, doorways, windows, all entrances, <strong>under</strong> <strong>the</strong> sink, stove andrefrigerator, shelves, cabinets and around plumbing and utility installations.Residents were advised not to re-enter <strong>the</strong>ir premise <strong>for</strong> two hours.“Conclusions: This study suggested that toxicologically-significantexposure <strong>of</strong> applicators and residents can occur during and immediatelyfollowing <strong>the</strong> application <strong>of</strong> dichlorvos. Although this study had somedeficiencies (such as <strong>the</strong> lack <strong>of</strong> reporting detail and <strong>the</strong> small sample sizes),it had qualitative value <strong>for</strong> risk assessment purposes.‖ (Originals notsighted; APVMA, 2008a)“In an intermediate-duration 21-day study in which volunteers weregiven dichlorvos orally, no signs <strong>of</strong> neurological toxicity were seen atdoses <strong>of</strong> 0.033 mg/kg [b.w.]/day (Boyer et al. 1977). Twenty-four malevolunteers had <strong>the</strong>ir serum cholinesterase and erythrocyteacetylcholinesterase determined twice a week <strong>for</strong> 3 weeks to establish<strong>the</strong>ir baseline levels. They were <strong>the</strong>n given 0.9 mg dichlorvos 3 times aday <strong>for</strong> 21 days in ei<strong>the</strong>r a pre-meal capsule or a 3-ounce container <strong>of</strong>gelatin. Serum cholinesterase and erythrocyte acetylcholinesterasewere measured twice a week during <strong>the</strong> exposure period. Once a week,each volunteer had his vital signs measured, and was examined <strong>for</strong>tremor, pupillary response to light, and skin moisture. Following.<strong>the</strong>end <strong>of</strong> <strong>the</strong> study, serum cholinesterase and erythrocyteacetylcholinesterase were measured weekly <strong>for</strong> <strong>the</strong> next seven weeks.No clinical signs <strong>of</strong> neurological toxicity were observed in any <strong>of</strong> <strong>the</strong>Dichlorvos reassessment – application Page 251 <strong>of</strong> 436
volunteers. Erythrocyte acetylcholinesterase was not inhibited at 0.033mg/kg [b.w.]/day in ei<strong>the</strong>r <strong>the</strong> gelatin or capsule <strong>for</strong>mulation. Serumcholinesterase was inhibited, on average, 38% in <strong>the</strong> group given <strong>the</strong>pre-meal capsule and 28% in <strong>the</strong> gelatin group. Measurements after <strong>the</strong>dosing period showed that <strong>the</strong> half-life <strong>for</strong> regeneration <strong>of</strong> serumcholinesterase was 13.7 days.” (Originals not sighted; ATSDR, 1997)The WHO (1978) reported:―Oral - Dichlorvos given to a group <strong>of</strong> 5 men in daily doses <strong>of</strong> 2.5 mgreduced after 20 days feeding plasma cholinesterase activity to 70% <strong>of</strong> preexposurelevel.―Symptoms <strong>of</strong> poisoning became evident when human subjects reached adose level <strong>of</strong> 8 mg/kg [b.w.] after receiving daily doubling doses starting at 1mg/kg [b.w.]. At this dosage <strong>the</strong> erythrocyte cholinesterase activity wasfound 20-55% <strong>of</strong> normal.―In studies designed to test <strong>the</strong> safety <strong>of</strong> using dichlorvos <strong>for</strong> <strong>the</strong>disinsection <strong>of</strong> aircraft, a group <strong>of</strong> 15 volunteers <strong>under</strong>went intermittentexposure totalling 5 hours per night, 4 nights per week, <strong>for</strong> 2 weeks, at aconcentration <strong>of</strong> 0.5 mg/m 3 <strong>of</strong> air; this produced a gradual, moderatereduction <strong>of</strong> plasma cholinesterase activity, but no illness, no impairment <strong>of</strong>visual per<strong>for</strong>mance, no increase in airway resistance <strong>of</strong> complex reactiontime, and no change in physical condition or neurological function. Therewas no inhibition <strong>of</strong> erythrocyte cholinesterase activity, and <strong>the</strong> lowestsingle plasma value observed was 34% <strong>of</strong> normal. Exposure to half thatconcentration <strong>for</strong> 10 half-hour periods each night <strong>for</strong> 10 weeks was toleratedwithout any effect, even on plasma cholinesterase.―Inhalation - Volunteers were exposed to an average dichlorvosconcentration <strong>of</strong> 5.8 mg/m 3 20 hours a day <strong>for</strong> up to 20 days. Plasmacholinesterase activity was reduced to 80%, 70% and 60% <strong>of</strong> normal after12, 24 and 48 hours respectively.‖ (Originals not sighted; WHO, 1978)Also see Section 25: Acceptable Operator Exposure Level (AOEL) – Key Study.Dichlorvos reassessment – application Page 252 <strong>of</strong> 436
25 ACCEPTABLE OPERATOR EXPOSURE LEVEL (AOEL)ERMA New Zealand usually sets one AOEL, derived from short or medium term(animal) studies with uncertainty factors and designed to protect <strong>the</strong> highest riskoccupational groups (such as contract sprayers) potentially exposed over seasonalperiods.AOELs are <strong>for</strong> systemic exposures, i.e. internal dose where any absorption factors(
25.1 Key Study:KEY STUDY: Oral• Type <strong>of</strong> study:• Species:• Strain:• Sex/Numbers:• Test material:• Dose levels:Minimal incipient toxicity, human;Human;Not applicable;4 or 5 males/test group; 2 male controls;Dichlorvos (unspecified source, Batch/Lot No. & purity);1.0, 1.5, 2.0 or 2.5 mg/day by capsule <strong>for</strong> 28 days (<strong>for</strong>70kg adult, equivalent to 0.014, 0.021, 0.029 and 0.036mg/kg b.w./day);• Endpoint: Symptoms; plasma and RBC ChE activities(potentiometric method <strong>of</strong> Michel (1949), which estimates<strong>the</strong> cholinesterase activity based on <strong>the</strong> change in pH withtime, ΔpH/hour); clinical chemistry, haematology andurinary parameters;• Remarks: No treatment-related symptoms or effect on anyhaematology, clinical chemistry or urinary parameter were reported. RBC ChEactivity was unaffected by treatment.No effect on plasma ChE activity at 1 or 1.5 mg/day was reported following 4weeks <strong>of</strong> dosing, however, no data were provided to substantiate this finding.At 2.0 mg/day, mean plasma ChE activity was depressed by >20% relative topretreatment activity from <strong>the</strong> second week <strong>of</strong> administration, reaching amaximum <strong>of</strong> 29% 3 days after treatment ended. When <strong>the</strong> data were correctedto account <strong>for</strong> this reduction in activity in <strong>the</strong> controls (up to 12%), <strong>the</strong> level <strong>of</strong>inhibition in <strong>the</strong> dichlorvos group was approximately 20% from <strong>the</strong> secondweek <strong>of</strong> dosing (maximum <strong>of</strong> 25% at day 19). This was considered atoxicologically significant level <strong>of</strong> inhibition despite <strong>the</strong> absence <strong>of</strong> statisticalanalysis to support <strong>the</strong> finding. Three days after <strong>the</strong> cessation <strong>of</strong> dosing, plasmaChE activity remained depressed by 22%.At 2.5 mg/day, toxicologically-significant inhibition (>20% relative topretreatment activity) <strong>of</strong> plasma ChE activity occurred after 2 weeks <strong>of</strong> dosing.Treatment was stopped after 20 days because <strong>the</strong> level <strong>of</strong> inhibition hadreached 30%. Following a 15-day washout period, plasma ChE activityreturned to pretreatment levels.A supplementary group <strong>of</strong> subjects was treated with 1.5 mg/g dichlorvos.Progressive inhibition <strong>of</strong> plasma ChE activity occurred from <strong>the</strong> second week,reaching a maximum <strong>of</strong> 41% at <strong>the</strong> end <strong>of</strong> <strong>the</strong> 60-day treatment period (relativeDichlorvos reassessment – application Page 254 <strong>of</strong> 436
to pretreatment activity). When <strong>the</strong> data were corrected to account <strong>for</strong> <strong>the</strong>declining activity in <strong>the</strong> control group (up to 24%), inhibition <strong>of</strong> plasma ChEactivity in <strong>the</strong> dichlorvos subjects was 27% after 16 days and continued to bedepressed by 13-21% <strong>for</strong> <strong>the</strong> remainder <strong>of</strong> <strong>the</strong> dosing period. During <strong>the</strong> 74-day post-treatment period, plasma ChE activity recovered to control levelswithin 2 weeks. The author indicated that over a period <strong>of</strong> approximately 3weeks (corresponding to post-treatment days 31-48), <strong>the</strong>re was a generaldecrease in plasma ChE activity in <strong>the</strong> per<strong>for</strong>ming laboratory due to a technicalproblem.• NOAEL =• LOAEL =• GLP:• Test Guideline:1.0 mg/day (0.014 mg/kg b.w./day <strong>for</strong> 70kg adult);1.5 mg/day (based on toxicologically-significant inhibition(>20% <strong>of</strong> pretreatment levels) <strong>of</strong> plasma ChE activity).No in<strong>for</strong>mation;No in<strong>for</strong>mation;• Reference source: Rider JA (1967) ―Determination <strong>of</strong> <strong>the</strong> minimal incipienttoxicity <strong>of</strong> dichlorvos in humans.‖ Report and Study no.unspecified. Lab: Gastrointestinal Research Laboratory,Franklin Hospital, San Francisco, CA, USA. Sponsor:Shell Chemical Company, Agricultural ChemicalsDivision, New York, New York, USA. Report date:October 1967. Unpublished. (Original not sighted;APVMA, 2008a);• Reliability:Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Key Study status: Rider (1967) was not conducted to GLP or TestGuideline. However, <strong>the</strong> APVMA considered <strong>the</strong> study robust enough to use <strong>the</strong>NOAEL as basis <strong>of</strong> <strong>the</strong>ir occupational and residential risk assessments.Note: The APVMA (2008a) concluded that:“The NOEL was 1.0 mg/d[ay], based on toxicologically-significant inhibition<strong>of</strong> plasma ChE activity at and above 1.5 mg/d[ay]. In <strong>the</strong> absence <strong>of</strong>bodyweight data <strong>for</strong> <strong>the</strong> test subjects it is assumed that <strong>the</strong> average bodyweight<strong>for</strong> young healthy men is 70 kg. There<strong>for</strong>e <strong>the</strong> NOEL, using this figure, is0.014 mg/kg bw/d[ay].‖[See Appendix 1: APVMA - Summary <strong>of</strong> benchmarks used in occupational riskassessments, <strong>for</strong> fuller details.]KEY STUDY: Oral• Type <strong>of</strong> study:21-day capsule study in humans;Dichlorvos reassessment – application Page 255 <strong>of</strong> 436
• Species:• Strain:• Sex/Numbers:• Test material:• Dose levels:• Endpoint:Humans;Not applicable;6 males/group;Dichlorvos (AMVAC Chemical Corp., Batch/Lot No.6080028074; 98% purity);7.0 mg/day by capsule <strong>for</strong> 21 days (<strong>for</strong> 70kg adult,equivalent to 0.1 mg/kg b.w./day);Symptoms & clinical parameters; RBC ChE activities;clinical chemistry, haematology and urinary parameters;• Remarks: Sporadic symptoms were reported by both treated andplacebo groups, and none were attributed to treatment.A clear time-related increase in <strong>the</strong> inhibition <strong>of</strong> RBC ChE activity wasreported, which was not evident in <strong>the</strong> placebo group. Mean RBC ChE activitywas significantly lower (p
cholinesterase inhibition in healthy male volunteers.‖ (STUDY PROTOCOL)CTL Study No. XH6063. Lab: Zeneca Central Toxicology Laboratory,Alderley Park, Macclesfield, Cheshire, UK and Medeval Limited, University<strong>of</strong> Manchester, Manchester Science Park, Manchester, UK. Sponsor: AMVACChemical Corporation, unspecified location. Study duration: 5 th November1996 to an unspecified time. Report date: unspecified. October 1997. (Originalnot sighted; APVMA, 2008a);• Reliability: Klimisch score 2 = reliable with restrictions;Justification <strong>for</strong> Key Study status: The study by Gledhill (1997b & 1997c) andMorris (1996b) was conducted to GLP. The USEPA considered <strong>the</strong> study robustenough to use <strong>the</strong> NOAEL as basis <strong>of</strong> <strong>the</strong>ir occupational and residential riskassessments.Background:The US EPA have determined that ChE inhibition by organophosphorus pesticidesreaches a steady state after 21 to 28 days exposure (USEPA, 2006b) so <strong>the</strong>se studyperiods are adequate <strong>for</strong> occupational and bystander/resident risk assessments.The US EPA prefers to use RBC AChE inhibition, because:―Although a pesticide‘s effect(s) on ei<strong>the</strong>r RBC and plasma cholinesteraseactivity is considered to provide in<strong>for</strong>mation on its potential to inhibit AChEin <strong>the</strong> nervous system, data from RBCs, which contain AChE exclusively,may better reflect neuronal AChE inhibition than data from <strong>the</strong> plasma,which is a variable mixture <strong>of</strong> butyrylcholinesterase andacetylcholinesterase.‖ (USEPA, 2000).The US EPA also reported levels <strong>of</strong> AChE inhibition and worker safety:―For example, <strong>the</strong> Cali<strong>for</strong>nia Department <strong>of</strong> Health Services (CDHS)requires monitoring <strong>of</strong> agricultural workers who have contact with highlytoxic organophosphorous or carbamate compounds (EPA Toxicity CategoryI or II pesticides; LD 50 # 500 mg/kg in rats)(CDHS, 1988). CDHS removesworkers from <strong>the</strong> workplace whose plasma levels show 40% or greatercholinesterase inhibition from baseline, or whose red blood cellcholinesterase levels show 30% or greater inhibition. Workers may notreturn until <strong>the</strong>ir cholinesterase values return to within 80% <strong>of</strong> baseline. TheWorld Health Organization (WHO) also has guidelines with <strong>the</strong> same RBCaction levels (i.e., 30% or greater inhibition), and considers plasmainhibition <strong>of</strong> 50% <strong>of</strong> baseline to indicate a "toxic" decrease (Fillmore andLessinger, 1993).‖ (Originals not sighted; USEPA, 2000).The WHO (1987) reported a study where symptoms <strong>of</strong> poisoning became evident whenhuman subjects reached a dose level <strong>of</strong> 8 mg/kg b.w. and <strong>the</strong> RBC cholinesteraseactivity was found 20-55% <strong>of</strong> normal. Whereas, volunteers <strong>under</strong>going intermittentinhalation exposure that resulted in no inhibition <strong>of</strong> erythrocyte cholinesterase activity,and <strong>the</strong> lowest single plasma value observed was 34% <strong>of</strong> normal reported no illness, noDichlorvos reassessment – application Page 257 <strong>of</strong> 436
impairment <strong>of</strong> visual per<strong>for</strong>mance, no increase in airway resistance <strong>of</strong> complex reactiontime, and no change in physical condition or neurological function.The critical NOAELs/LOAELs set by overseas regulatory agencies are listed in <strong>the</strong>table below:Critical NOAEL/LOAEL used <strong>for</strong> occupational exposure health benchmarks (mg/kgb.w./day)AcuteShort-term(1 day) a (1-30 Days a )Study Type(Reference)Intermediate(Seasonal, 1-6Months a )US EPA (2006a) Dermal BMDL 10 Dermal LOAEL == 0.8 c0.1Inhalation InhalationBMDL 10 = 0.8 c (vapours) LOAEL= 0.1 dRat acute oral (Twomey, 2002) bHuman 21D oral (Gledhill, 1997a &1997b)Inhalation(application)LOAEL = 0.1APVMA (2008b) Dermal NOAEL =0.014Human 28D oral (Rider, 1967)InhalationNOAEL = 0.014abUS EPA;Acute time point;c (0.8 mg/kg bw/day x 0.35kg / 0.34 m 3 /day = 0.8 mg/m 3 );d concentration equivalent = 0.35 mg/m 3 (= 0.1 mg/kg bw/day x 70kg / 20 m 3 /day);25.2 AOEL:Reliance on <strong>the</strong> NOAEL from Rider (1967) <strong>for</strong> occupational and bystander/resident riskassessments, in line with <strong>the</strong> APVMA, should give a conservative benchmark as:a) <strong>the</strong> Rider (1967) NOAEL is based plasma ChE, noted as <strong>the</strong> most sensitivemarker <strong>for</strong> repeat dichlorvos exposure; and,b) <strong>the</strong> action level used by <strong>the</strong> Cali<strong>for</strong>nia Department <strong>of</strong> Health Services (CDHS)and guidance level recommended by <strong>the</strong> World Health Organization (WHO) toDichlorvos reassessment – application Page 258 <strong>of</strong> 436
protect agricultural workers who have contact with highly toxicorganophosphorous or carbamate compounds are ≥30% RBC ChE inhibition.Most data indicate RBC ChE inhibition would reach ~20% (as used by <strong>the</strong> USEPA; Gledhill, 1997b & 1997c) at approximately 10x <strong>the</strong> Rider (1967) NOAELdose.Proposed AOEL:AOEL = NOAEL x AF = 0.014 x 1.0= 0.0014 mg/kg b.w./dayUFs 10From <strong>the</strong> 28-day human volunteer capsule study (Rider, 1967 in APVMA, 2008aand US EPA, 2006a).Where UFs: inter-species = 1 as <strong>the</strong> study was carried out in humans; intra-species= 10 to account <strong>for</strong> individual variability; and AF (absorption factor) = 1.0 (100%)<strong>for</strong> oral absorption.Dichlorvos reassessment – application Page 259 <strong>of</strong> 436
Absorption factors:[See Section 4 ADME <strong>for</strong> fur<strong>the</strong>r discussion on absorption.]Dermal absorption factorThe APVMA, US EPA and Cal DPR all reviewed Jeffcoat (1990) [MRID 41435201]and used this study as <strong>the</strong> basis <strong>of</strong> <strong>the</strong>ir dermal absorption factors, respectively 30, 11and 13%.The discrepancy between <strong>the</strong> APVMA and US EPA (and Cal DPR) dermal absorptionfactors, although based on <strong>the</strong> same study and data, is due to <strong>the</strong>ir differentinterpretations on what constitutes absorbed material. The APVMA have considered―dermal absorption‖, to include that amount <strong>of</strong> material remaining in <strong>the</strong> skin at <strong>the</strong> time<strong>the</strong> study ended, approximately 22-30% predominately within <strong>the</strong> first 10 hours(carcass, skin, urine, faeces, blood and expired air). Whereas <strong>the</strong> US EPA have onlyconsidered ―dermal penetration‖, that excluded <strong>the</strong> material in <strong>the</strong> skin and onlyincluded that in <strong>the</strong> carcass, urine, faeces, blood and expired air, approximately 6-11%.At <strong>the</strong> medium and highest dose rates (3 & 30 μg/cm 2 ) <strong>the</strong> dermal absorption valueswere higher at 10 hours than at later time points, while at <strong>the</strong> lowest dose (0.5 μg/cm 2 )<strong>the</strong> percentage <strong>of</strong> <strong>the</strong> applied dose absorbed was slightly higher.(APVMA, 2008a)The available data do not conclusively show if <strong>the</strong> skin acts as a reservoir <strong>of</strong> dichlorvosor not. However, at 120 hours <strong>the</strong> radioactivity in carcass and blood has declined, whilethat in urine, faeces and expired air has increased, indicating that any materialpenetrating <strong>the</strong> skin after <strong>the</strong> first 10 hours does not appear to be contributing to peakbody burden (systemic dose), but may maintain levels over toxic thresholds. Thedegradation <strong>of</strong> dichlorvos by tissue esterases, particularly in <strong>the</strong> liver and <strong>the</strong>serum is described as rapid, but <strong>the</strong> differences in oral and dermal LD50 values(oral: 46.4 mg/kg b.w.; dermal: 75 mg/kg b.w. <strong>for</strong> females) does not indicate o<strong>the</strong>rsignificant factors <strong>for</strong> oral to dermal extrapolations.There<strong>for</strong>e, 30% is recommended as <strong>the</strong> dermal absorption factor as <strong>the</strong> mostconservative value <strong>for</strong> occupational and bystander/resident risk assessments.Dichlorvos reassessment – application Page 260 <strong>of</strong> 436
Wash: refers to skin washes; Dressing: refers to test material in <strong>the</strong> covering dressing itself; Charcoalfilter: refers to material absorbed into charcoal filters placed <strong>under</strong> <strong>the</strong> covering dressings (vapour).(APVMA, 2008a)Inhalation absorption factorThe APVMA concluded that a 70% inhalation absorption factor would be used <strong>for</strong> riskassessment purposes, based on a study (Kirkland, 1971) evaluated by <strong>the</strong> WHO (1988)that demonstrated that at dichlorvos concentrations <strong>of</strong> 0.1–2.0 mg/m 3 , pigs retained 15–70% <strong>of</strong> <strong>the</strong> inhaled dichlorvos. (APVMA, 2008b)The US EPA has used 100% <strong>for</strong> <strong>the</strong> inhalation absorption factor (US EPA, 2006).Due to paucity <strong>of</strong> data, 100% inhalation absorption factor is recommended.Oral absorption factorThe APVMA evaluated oral absorption to be almost complete (93-96%) and rapidTmax < 0.5h (APVMA, 2008a).100% oral absorption factor is recommended.Dichlorvos reassessment – application Page 261 <strong>of</strong> 436
26 SUMMARY & CONCLUSIONSCLASS 6 & 8 Toxicological Hazard Classifications:Hazard Class/SubclassHazardclassificationMethod <strong>of</strong> classificationReferenceSubclass 6.1 Acutetoxicity (oral)Subclass 6.1Acute toxicity(dermal)Subclass 6.1 Acutetoxicity (inhalation)Subclass 6.3/8.2 Skinirritancy/corrosionSubclass 6.4/8.3 Eyeirritancy/corrosion6.1B LD 50 (rat, oral) = 46.4 mg/kg b.w.GLP: NoGuideline: NoKlimisch score 2 = reliable withrestrictions6.1B LD 50 (rat, dermal) = 75 mg/kg b.w.GLP: NoGuideline: NoKlimisch score 2 = reliable withrestrictions6.1B LC 50 (rat, head-only; mist) = 0.447mg/LGLP: YesGuideline: OECD [403?]Klimisch score 2 = reliable withrestrictions6.3B Primary dermal irritation (rabbit)GLP: NoGuideline: OECD 404Klimisch score 2 = reliable withrestrictions6.4A Primary eye irritation (rabbit)GLP: NoGuideline: OECD 405Klimisch score 2 = reliable withrestrictionsCiba-Geigy (1973)(APVMA, 2008a)Durham et al. (1957)(ATSDR, 1997)Pauluhn J (1984)(APVMA, 2008a)Pauluhn J (1985)(APVMA, 2008a)Pauluhn J (1985)(APVMA, 2008a)Subclass 6.5A RespiratorysensitisationInsufficientdataNo dataAPVMA, USEPA,ATSDR, WHODichlorvos reassessment – application Page 262 <strong>of</strong> 436
Hazard Class/SubclassHazardclassificationMethod <strong>of</strong> classificationReferenceSubclass 6.5B Contactsensitisation6.5B Maximisation Test (Guinea Pig)GLP: NoGuideline: NoKlimisch score 2 = reliable withrestrictionsUeda et al. (1994)(APVMA, 2008a)Subclass 6.6 Mutagenicity 6.6B Weight <strong>of</strong> evidence:Dichlorvos is mutagenic andclastogenic at <strong>the</strong> point <strong>of</strong> contact,where unchanged dichlorvos may be indirect contact with tissue [DDVP‘sinherent potential]. There is noevidence that dichlorvos has anysystemic genotoxic potential, due to<strong>the</strong> substance‘s inherentphosphorylating reactivity and <strong>the</strong>highly efficient biotrans<strong>for</strong>mation [lowrisk].APVMA, USEPA,ATSDR, WHOSubclass 6.7Carcinogenicity6.7B Weight <strong>of</strong> evidence:The increased incidence <strong>of</strong> adenomas<strong>of</strong> <strong>the</strong> exocrine pancreas in maleF344/N rats after dietary exposureindicated equivocal evidence <strong>of</strong>carcinogenic activity <strong>of</strong> dichlorvos, asan inhalation study revealed no similareffects. The increased incidences <strong>of</strong><strong>for</strong>estomach squamous cell papillomasin male and female B6C3F1 mice afterdietary exposure indicated someevidence. While <strong>for</strong>estomach tumoursare not considered directly relevant tohumans, <strong>the</strong>se findings (and <strong>the</strong>mutagenic potential in certain contactscenarios) indicate that repeatedexposure to high concentrations <strong>of</strong>dichlorvos poses some carcinogenichazard, even though <strong>the</strong> occupationand residential risks are seen asnegligible.APVMA, USEPA,ATSDR, WHOSubclass 6.8 ReproductivetoxicityNoOPPTS 870.3800 (Reproductive);OECDTyl (1992) in APVMA,2008aGLP: US EPA, 40 CFR Part 160;USEPA, ATSDR, WHOKlimisch score 2 = reliable withrestrictionsDichlorvos reassessment – application Page 263 <strong>of</strong> 436
Hazard Class/SubclassHazardclassificationMethod <strong>of</strong> classificationReferenceSubclass 6.8Developmental toxicityNo(Rat, developmental)(Rabbit, develop.)GLP: US EPA, 40 CFR Part 160;Tyl (1990a and 1990b) inAPVMA, 2008aUSEPA, ATSDR, WHOKlimisch score 2 = reliable withrestrictionsSubclass 6.8 Category CInsufficientdata <strong>for</strong> CInsufficient data <strong>for</strong> Classification onlactation effects (C)APVMA, USEPA,ATSDR, WHOSubclass 6.9 Target organsystemic toxicity – Singleexposure (Oral)Subclass 6.9 Target organsystemic toxicity – Singleexposure (Dermal)Subclass 6.9 Target organsystemic toxicity – Singleexposure (Inhalation)Subclass 6.9 Target organsystemic toxicity – Repeatexposure (Oral)6.9A LOAEL = 35 mg/kg b.w., based onclinical signs <strong>of</strong> neurotoxicity (FOB)(peak effect 15 mins)US EPA Guideline Series 81-8 (1991);GLP: US EPA, 40 CFR Part 160;Klimisch score 2 = reliable withrestrictions6.9B LOAEL = 150 mg/kg b.w., based onclinical signs <strong>of</strong> neurotoxicity;Guideline: No in<strong>for</strong>mation;GLP: No in<strong>for</strong>mation;Klimisch score 2 = reliable withrestrictions6.9A LOAEL = 0.23-1.926 mg/L, based onclinical signs <strong>of</strong> neurotoxicity;Guideline: OECD 403?;GLP: Yes;Klimisch score 2 = reliable withrestrictions6.9A LOAEL = 3.2 ppm (equivalent to 0.08mg/kg b.w./day) based on inhibition <strong>of</strong>RBC ChE activity in males(Dog, 2-Yr Dietary)Lamb (1993a) inAPVMA, 2008aUSEPA, ATSDR, WHOTierfarm (1969b) inAPVMA, 2008aPauluhn (1984) inAPVMA, 2008aJolley et al. (1967) inAPVMA, 2008aLOAEL = 1.0 mg/kg b.w./day, basedon inhibition <strong>of</strong> plasma and RBC ChEactivities.US EPA; 40 CFR Part 160;Markiewicz (1990) inAPVMA, 2008aUSEPA, ATSDR, WHODichlorvos reassessment – application Page 264 <strong>of</strong> 436
Hazard Class/SubclassHazardclassificationMethod <strong>of</strong> classificationReferenceUS EPA (Subdivision F, series 158,83-1) (Dog, 52-Wk Capsule)Klimisch score 2 = reliable withrestrictionsSubclass 6.9 Target organsystemic toxicity – Repeatexposure (Dermal)InsufficientdataNo adequate studies were reportedAPVMA, USEPA,ATSDR, WHOSubclass 6.9 Target organsystemic toxicity – Repeatexposure (Inhalation)APVMA: APVMA, 2008a;USEPA: USEPA, 2006a;ATSDR: ATSDR, 1997;WHO: WHO, 1988 & 1993.6.9A LOAEL = 0.5 mg/m3 (approximatelyequal to 2.5 mg/kg/ b.w./day) based on<strong>the</strong> inhibition <strong>of</strong> plasma and RBC ChEactivity;GLP: NoGuideline: NoKlimisch score 2 = reliable withrestrictionsBlair et al. (1974 &1976) in APVMA, 2008aUSEPA, ATSDR, WHOThe level <strong>of</strong> detail in <strong>the</strong> APVMA Chemical Review (2008a), <strong>the</strong> US EPAReregistration Eligibility Decision <strong>for</strong> Dichlorvos (2006a), <strong>the</strong> ATSDR ToxicologicalPr<strong>of</strong>ile (1997) and WHO reports (1988 & 1993), should give adequate assurance that<strong>the</strong> proposed Classifications are robust, based on <strong>the</strong> documents cited in <strong>the</strong> Referencesection.Key Studies <strong>for</strong> AOEL benchmark:Critical NOAEL/LOAEL used <strong>for</strong> occupational exposure health benchmarks (mg/kgb.w./day)AcuteShort-term(1 day) a (1-30 Days a )Study Type(Reference)Intermediate(Seasonal, 1-6Months a )US EPA (2006a) Dermal BMDL 10 Dermal LOAEL = Rat acute oral (Twomey, 2002) bDichlorvos reassessment – application Page 265 <strong>of</strong> 436
Critical NOAEL/LOAEL used <strong>for</strong> occupational exposure health benchmarks (mg/kgb.w./day)= 0.8 c0.1Inhalation InhalationBMDL 10 = 0.8 c (vapours) LOAEL= 0.1 dHuman 21D oral (Gledhill, 1997a &1997b)Inhalation(application)LOAEL = 0.1APVMA (2008b) Dermal NOAEL =0.014Human 28D oral (Rider, 1967)InhalationNOAEL = 0.014abUS EPA;Acute time point;c (0.8 mg/kg bw/day x 0.35kg / 0.34 m 3 /day = 0.8 mg/m 3 );d concentration equivalent = 0.35 mg/m 3 (= 0.1 mg/kg bw/day x 70kg / 20 m 3 /day);Proposed AOEL:AOEL = NOAEL x AF = 0.014 x 1.0 = 0.0014 mg/kg b.w./dayUFs 10From <strong>the</strong> 28-day human volunteer capsule study (Rider, 1967 in APVMA, 2008aand US EPA, 2006a).Where UFs: inter-species = 1 as <strong>the</strong> study was carried out in humans; intra-species= 10 to account <strong>for</strong> individual variability.Based on <strong>the</strong> current available data package <strong>for</strong> dichlorvos, TCL has proposed:• dermal absorption at 30% <strong>for</strong> occupational and bystander/resident health riskmodelling.• inhalation absorption at 100% <strong>for</strong> occupational and bystander/resident healthrisk modelling.• oral absorption at 100% <strong>for</strong> occupational and bystander/resident health riskmodelling.Dichlorvos reassessment – application Page 266 <strong>of</strong> 436
REFERENCES:APVMA, 2008a. ―DICHLORVOS - Toxicology Assessment: The reconsideration <strong>of</strong>approvals <strong>of</strong> <strong>the</strong> active constituent, registrations <strong>of</strong> products containing dichlorvos andapprovals <strong>of</strong> <strong>the</strong>ir associated labels.‖ Australian Pesticides & Veterinary MedicinesAuthority, KINGSTON ACT 2604; 2008.APVMA, 2008b. ―DICHLORVOS - OCCUPATIONAL HEALTH AND SAFETYASSESSMENT: The reconsideration <strong>of</strong> approvals <strong>of</strong> <strong>the</strong> active constituent, registrations<strong>of</strong> products containing dichlorvos and approvals <strong>of</strong> <strong>the</strong>ir associated labels.‖ AustralianPesticides & Veterinary Medicines Authority, KINGSTON ACT 2604; 2008.ATSDR, 1997. “TOXICOLOGICAL PROFILE FOR DICHLORVOS” Agency <strong>for</strong> Toxic<strong>Substance</strong>s and Disease Registry, Atlanta, Georgia 30333; 1997.CCRIS, 2008. Chemical Carcinogenesis Research In<strong>for</strong>mation System (CCRIS) 2008:DICHLORVOS CASRN: 62-73-7.ERMA, 2008. ―User Guide to <strong>the</strong> Thresholds and Classifications in <strong>the</strong> HSNO Act.‖v2.0 March 2008: ER-UG-03-2 02/08. ERMA New Zealand, WELLINGTON.IARC, 1991. ―International Agency <strong>for</strong> Research on Cancer (IARC) - Summaries &Evaluations: DICHLORVOS (Group 2B).‖ VOL.: 53 (1991) (p. 267).http://www.inchem.org/documents/iarc/vol53/06-dichlorvos.htmlPletsa V, Steenwinkel MJ, van Delft JH, Baan RA, Kyrtopoulos SA., 1999. ―Induction<strong>of</strong> somatic mutations but not methylated DNA adducts in lambdalacZ transgenic miceby dichlorvos.‖ Cancer Lett. 1999 Nov 15;146(2):155-60.Schop RN, Hardy MH, Goldberg MT., 1990. ―Comparison <strong>of</strong> <strong>the</strong> activity <strong>of</strong> topicallyapplied pesticides and <strong>the</strong> herbicide 2,4-D in two short-term in vivo assays <strong>of</strong>genotoxicity in <strong>the</strong> mouse.‖ Fundam Appl Toxicol. 1990 Nov;15(4):666-75.Tungul, A., Bonin, A.M., He, S., Baker R.S.U., 1991. ―Micronuclei induction bydichlorvos in <strong>the</strong> mouse skin.‖ Mutagenesis vol. 6 no. 5 pp. 405-408, 1991.US EPA, 2000. ―Science Policy on The Use <strong>of</strong> Data on Cholinesterase Inhibition <strong>for</strong>Risk Assessments <strong>of</strong> Organophosphorous and Carbamate Pesticides.‖ August 18, 2000.Office <strong>of</strong> Pesticide Programs, US Environmental Protection Agency, Washington DC20460.US EPA, 2006a. ―Reregistration Eligibility Decision <strong>for</strong> Dichlorvos (DDVP).‖ Office<strong>of</strong> Pesticide Programs, UNITED STATES ENVIRONMENTAL PROTECTIONAGENCY, WASHINGTON D.C., 20460.US EPA, 2006b. ―Organophosphorus Cumulative Risk Assessment – 2006 Update‖(August 2006) U.S. Environmental Protection Agency, Office <strong>of</strong> Pesticide Programs.WHO, 1978. ―DICHLORVOS.‖ DATA SHEETS ON PESTICIDES No. 2 (Rev.1)August 1978, World Health Orgnization, Geneva,Dichlorvos reassessment – application Page 267 <strong>of</strong> 436
WHO, 1988. ―INTERNATIONAL PROGRAMME ON CHEMICAL SAFETYENVIRONMENTAL HEALTH CRITERIA 79: DICHLORVOS.‖ World HealthOrgnization, Geneva, 1988.WHO, 1993. ―859_ Dichlorvos (Pesticide residues in food 1993 evaluations Part IIToxicology).” World Health Orgnization, Geneva.Dichlorvos reassessment – application Page 268 <strong>of</strong> 436
Appendix 1:APVMA - Summary <strong>of</strong> benchmarks used in occupational riskassessments (APVMA, 2008b).“NOELs <strong>for</strong> Occupational Health & Safety Assessment―Dichlorvos products intended <strong>for</strong> pr<strong>of</strong>essional use are most likely to be applied byPCOs [pest control operators], horticulturalists and operators <strong>of</strong> grain storage facilitiesand flour mills. Depending on pest activity, PCOs may use dichlorvos products onseveral days or daily during <strong>the</strong> working week. Repeated use <strong>of</strong> dichlorvos <strong>for</strong> treatment<strong>of</strong> commercial and industrial buildings could result in daily exposure <strong>of</strong> buildingoccupants, given that dichlorvos has been detected in workplace atmospheres <strong>for</strong> up to a<strong>for</strong>tnight after application (Sch<strong>of</strong>ield, 1993). Grain storage operators and avocadogrowers are more likely to be exposed on a seasonal basis, but also may be exposed onseveral days in succession. Exposure <strong>of</strong> horticulturalists would be dictated by <strong>the</strong>growth cycle <strong>of</strong> mushrooms or plants <strong>under</strong> cultivation, and could occur regularly onsingle days but with several days or more between uses. The most likely potential routes<strong>of</strong> exposure would be by dermal contact with <strong>the</strong> undiluted products or spray mixture,and by inhalation <strong>of</strong> dichlorvos vapour or aerosols.“Dermal NOEL <strong>for</strong> Occupational Exposure Assessment―Short-term repeat-dose toxicity studies <strong>of</strong> up to 28 days‘ duration are considered to be<strong>the</strong> most appropriate <strong>for</strong> derivation <strong>of</strong> NOELs <strong>for</strong> occupational health and safetyassessment <strong>of</strong> product users who are exposed repeatedly. The most relevanttoxicological end-point <strong>for</strong> occupational exposure to dichlorvos is plasma ChEinhibition, as in a repeated exposure scenario, <strong>the</strong>re would be scope <strong>for</strong> progressivelyincreasing inhibition <strong>of</strong> plasma ChE activity if <strong>the</strong> (less sensitive) RBC ChE inhibitionwere used as <strong>the</strong> pivotal end-point. Although repeat-dose studies via <strong>the</strong> dermal routewould be optimal <strong>for</strong> derivation <strong>of</strong> occupational health and safety NOELs, no suchstudies with dichlorvos are available. The assessment <strong>the</strong>re<strong>for</strong>e must be per<strong>for</strong>medusing studies <strong>under</strong>taken by oral administration. A summary <strong>of</strong> NOELs determined inoral studies considered adequate <strong>for</strong> regulatory purposes is shown in <strong>the</strong> followingtable:Dichlorvos reassessment – application Page 269 <strong>of</strong> 436
―It is considered that <strong>the</strong> most suitable endpoint <strong>for</strong> estimation <strong>of</strong> occupational risks <strong>for</strong>dermal exposures is an oral NOEL <strong>of</strong> 0.014 mg/kg bw/d[ay], established in <strong>the</strong> 28-d[ay]oral study in humans by Rider (1967). The study is highly suitable because itdemonstrated a NOEL and a LOEL <strong>for</strong> plasma ChE inhibition and was per<strong>for</strong>med withhuman subjects, <strong>the</strong>reby eliminating uncertainty associated with inter-speciesextrapolation. Adjusting <strong>for</strong> a dermal absorption factor <strong>of</strong> 30%, <strong>the</strong> resulting dermalNOEL becomes 0.047 mg/kg bw/d[ay]. The acceptable margin <strong>of</strong> exposure (MOE) is >10, resulting from application <strong>of</strong> a 10-fold uncertainty factor <strong>for</strong> intra-speciesvariability. No correction <strong>for</strong> an internal dose is required since absorption from <strong>the</strong> GITis almost complete (93 – 96%).Dichlorvos reassessment – application Page 270 <strong>of</strong> 436
“Inhalational NOEL <strong>for</strong> Occupational Exposure Assessment―Due to <strong>the</strong> volatile nature <strong>of</strong> dichlorvos, <strong>the</strong>re is highly significant potential <strong>for</strong> productusers to be exposed via inhalation, especially during spray application. For productusers, <strong>the</strong> frequency <strong>of</strong> inhalation exposure in an occupational setting would be <strong>the</strong>same as <strong>for</strong> dermal exposure, as discussed above. Persons exposed occupationally intreated buildings are likely to be exposed by inhalation repeatedly on successive days.―Several short-term studies have been <strong>under</strong>taken in which ChE activity was measuredin humans exposed to dichlorvos by inhalation. However, <strong>the</strong>ir usefulness is limited byuncertainty concerning <strong>the</strong> NOECs and/or <strong>the</strong> airborne concentrations <strong>of</strong> dichlorvos towhich <strong>the</strong> subjects were exposed. It is <strong>the</strong>re<strong>for</strong>e necessary to per<strong>for</strong>m <strong>the</strong> assessmentusing studies carried out by oral administration. As discussed previously, <strong>the</strong> mostsuitable study <strong>for</strong> estimation <strong>of</strong> occupational risks is that <strong>of</strong> Rider (1967), in which <strong>the</strong>NOEL was 0.014 mg/kg bw/d[ay]. Adjusting <strong>for</strong> <strong>the</strong> inhalation absorption factor <strong>of</strong>70%, <strong>the</strong> resulting NOEL becomes 0.02 mg/kg bw/d[ay]. This value should be used <strong>for</strong>risk assessment <strong>of</strong> pr<strong>of</strong>essional users during application and on restricted entry intotreated areas. The acceptable margin <strong>of</strong> inhalation exposure (MOE) is > 10, resultingfrom application <strong>of</strong> a 10-fold uncertainty factor <strong>for</strong> intraspecies variability.‖ (APVMA,2008b)Key Study:“Rider JA (1967) Determination <strong>of</strong> <strong>the</strong> minimal incipient toxicity <strong>of</strong> dichlorvos inhumans. Report and Study no. unspecified. Lab: Gastrointestinal Research Laboratory,Franklin Hospital, San Francisco, CA, USA. Sponsor: Shell Chemical Company,Agricultural Chemicals Division, New York, New York, USA. Report date: October1967.Materials and Methods―Dichlorvos (unspecified source, Batch/Lot No. & purity), <strong>for</strong>mulated in corn oil, wasadministered to ―healthy young men‖ in gelatine capsules at 1.0, 1.5, 2.0 or 2.5mg/d[ay] <strong>for</strong> 28 days (equivalent to 0.014, 0.021, 0.029 and 0.036, respectively,assuming an average bodyweight <strong>of</strong> 70 kg). The doses were split between two capsules,which were ingested at 8 am and 3 pm. Few details were given regarding <strong>the</strong> subjects(such as age and bodyweight) o<strong>the</strong>r than that <strong>the</strong>y were serving sentences at <strong>the</strong>Cali<strong>for</strong>nian Medical Facility, Vacaville, Cali<strong>for</strong>nia, USA. Each subject was physicallyexamined and interviewed prior to <strong>the</strong> commencement <strong>of</strong> dosing. At each dose, 4 or 5subjects received <strong>the</strong> capsules containing dichlorvos, while 2 control subjects receivedcapsules containing only corn oil. An additional group <strong>of</strong> subjects received 0 (n=2) or1.5 mg/d[ay] (n=10) dichlorvos over 60 days followed by a recovery period <strong>of</strong> 74 days.Analysis <strong>of</strong> <strong>the</strong> concentration and stability <strong>of</strong> dichlorvos was not per<strong>for</strong>med.―All subjects were interviewed on a weekly basis and any symptoms recorded. Baselineplasma and RBC ChE activities were analysed over a 14-28 day period prior to dosingusing <strong>the</strong> potentiometric method <strong>of</strong> Michel (1949), which measures <strong>the</strong> ΔpH/h. Plasmaand RBC ChE activities were analysed 24 hours after <strong>the</strong> first dose and <strong>the</strong>n twiceweekly throughout <strong>the</strong> study. In <strong>the</strong> additional group <strong>of</strong> subjects dosed with 1.5mg/d[ay], plasma and RBC ChE activities were measured during <strong>the</strong> 74-day recoveryperiod. The following clinical chemistry parameters were measured prior to treatmentDichlorvos reassessment – application Page 271 <strong>of</strong> 436
and on a weekly basis <strong>for</strong> 4 weeks: SGOT, alkaline phosphatase, prothrombin time,thymol turbidity and total bilirubin. The following haematology parameters weremeasured prior to treatment and on a weekly basis <strong>for</strong> 4 weeks <strong>of</strong> dosing: Hct, Hb,RBC, WBC and WBC-DC. The following urinary parameters were measured prior totreatment and on a weekly basis <strong>for</strong> 4 weeks <strong>of</strong> dosing: pH, colour, character, specificgravity, albumin, sugar, leucocytes, erythrocytes, epi<strong>the</strong>lial cells, casts, crystals,amorphous and o<strong>the</strong>r.―No statistical analysis was per<strong>for</strong>med.Results―There were no treatment-related symptoms. There was no treatment-related effect onany haematology, clinical chemistry or urinary parameter. RBC ChE activity wasunaffected by treatment.―It was reported that <strong>the</strong>re was no effect on plasma ChE activity at 1 or 1.5 mg/d[ay]following 4 weeks <strong>of</strong> dosing, however, no data were provided to substantiate thisfinding. At 2.0 mg/d[ay], mean plasma ChE activity was depressed by >20% relative topretreatment activity from <strong>the</strong> second week <strong>of</strong> administration, reaching a maximum <strong>of</strong>29% 3 days after treatment ended (see Table below). However, <strong>the</strong> concurrent controlgroup also showed a reduction in plasma ChE activity (up to 12%) relative to its meanbaseline activity. When <strong>the</strong> data were corrected to account <strong>for</strong> this reduction in activityin <strong>the</strong> controls, <strong>the</strong> level <strong>of</strong> inhibition in <strong>the</strong> dichlorvos group was approximately 20%from <strong>the</strong> second week <strong>of</strong> dosing (maximum <strong>of</strong> 25% at day 19). This was considered atoxicologically significant level <strong>of</strong> inhibition despite <strong>the</strong> absence <strong>of</strong> statistical analysisto support <strong>the</strong> finding. Three days after <strong>the</strong> cessation <strong>of</strong> dosing, plasma ChE activityremained depressed by 22%.Plasma ChE activity in male subjects treated with 2.0 mg/d dichlorvos―Results expressed as <strong>the</strong> mean ΔpH/h, with <strong>the</strong> % inhibition relative to pretreatment activity contained inparen<strong>the</strong>ses. The range is shown <strong>for</strong> <strong>the</strong> dichlorvos group in paren<strong>the</strong>ses; 1 = % inhibition in <strong>the</strong> controlgroup subtracted from <strong>the</strong> % inhibition <strong>of</strong> <strong>the</strong> dichlorvos group; 2 = average <strong>of</strong> 4 measurements <strong>for</strong> eachsubject.―At 2.5 mg/d[ay] (see Table below), toxicologically-significant inhibition <strong>of</strong> plasmaChE activity occurred after 2 weeks <strong>of</strong> dosing (ie. >20% relative to pretreatmentDichlorvos reassessment – application Page 272 <strong>of</strong> 436
activity). In fact, treatment was stopped after 20 days because <strong>the</strong> level <strong>of</strong> inhibition hadreached 30%. Following a 15-day washout period, plasma ChE activity returned topretreatment levels.Plasma ChE activity in male subjects treated with 2.5 mg/d dichlorvos―Results expressed as <strong>the</strong> mean ΔpH/h, with <strong>the</strong> % inhibition relative to pretreatment activity contained inparen<strong>the</strong>ses. The range is also shown <strong>for</strong> <strong>the</strong> dichlorvos group in paren<strong>the</strong>ses; 1 = average <strong>of</strong> 4measurements <strong>for</strong> each subject.―In <strong>the</strong> supplementary group <strong>of</strong> subjects treated with 1.5 mg/g dichlorvos (see Tablebelow), progressive inhibition <strong>of</strong> plasma ChE activity occurred from <strong>the</strong> second week,reaching a maximum <strong>of</strong> 41% at <strong>the</strong> end <strong>of</strong> <strong>the</strong> 60-day treatment period (relative topretreatment activity). However, <strong>the</strong> magnitude <strong>of</strong> this effect was partially negated by<strong>the</strong> up to 24% reduction in plasma ChE activity in <strong>the</strong> concurrent controls over <strong>the</strong> sametime. When <strong>the</strong> data were corrected to account <strong>for</strong> <strong>the</strong> declining activity in <strong>the</strong> controlgroup, inhibition <strong>of</strong> plasma ChE activity in <strong>the</strong> dichlorvos subjects was 27% after 16days and continued to be depressed by 13-21% <strong>for</strong> <strong>the</strong> remainder <strong>of</strong> <strong>the</strong> dosing period.During <strong>the</strong> 74-day post-treatment period, plasma ChE activity recovered to controllevels within 2 weeks. The author indicated that over a period <strong>of</strong> approximately 3 weeks(corresponding to post-treatment days 31-48), <strong>the</strong>re was a general decrease in plasmaChE activity in <strong>the</strong> per<strong>for</strong>ming laboratory. This was apparently remedied when a freshacid cleaning solution was employed to clean <strong>the</strong> laboratory glassware used <strong>for</strong> <strong>the</strong> ChEassay.Dichlorvos reassessment – application Page 273 <strong>of</strong> 436
Plasma ChE activity in additional male subjects treated with 1.5 mg/d dichlorvos―Results expressed as <strong>the</strong> mean ΔpH/h, with <strong>the</strong> % inhibition relative to pretreatment activity contained inparen<strong>the</strong>ses. The range is shown <strong>for</strong> <strong>the</strong> dichlorvos group in paren<strong>the</strong>ses; 1 = only results <strong>for</strong> every secondtime point are shown; 2 = % inhibition in <strong>the</strong> control group subtracted from <strong>the</strong> % inhibition <strong>of</strong> <strong>the</strong>dichlorvos group; 3 = data <strong>for</strong> one control subject only compared to his own baseline activity <strong>of</strong> 0.851.“Conclusions: The NOEL was 1.0 mg/d[ay], based on toxicologically-significantinhibition <strong>of</strong> plasma ChE activity at and above 1.5 mg/d[ay]. In <strong>the</strong> absence <strong>of</strong>bodyweight data <strong>for</strong> <strong>the</strong> test subjects it is assumed that <strong>the</strong> average bodyweight <strong>for</strong>young healthy men is 70 kg. There<strong>for</strong>e <strong>the</strong> NOEL, using this figure, is 0.014 mg/kgbw/d[ay].‖ (Original not sighted; APVMA, 2008a)Dichlorvos reassessment – application Page 274 <strong>of</strong> 436
LAST PAGEDichlorvos reassessment – application Page 275 <strong>of</strong> 436
Appendix G: Human Health Risk AssessmentDichlorvos reassessment – application Page 276 <strong>of</strong> 436
Dichlorvos:Occupational, Bystander, and ResidentRisk AssessmentsFor:ERMA New Zealand20 Customhouse QuayPO Box 131WellingtonNEW ZEALANDPrepared by:Martin Edwards PhDToxicology Consulting Ltd36 Hastings ParadeDevonport 0624North Shore Cityedwardsm@ihug.co.nzVersion: V8March, 2010Dichlorvos reassessment – application Page 277 <strong>of</strong> 436
1 PURPOSE1.1 The purpose <strong>of</strong> this report is to provide occupational, bystander, and residentrisk assessments <strong>for</strong> <strong>the</strong> Environmental Risk Management Authority NewZealand (ERMA New Zealand) reassessment <strong>of</strong> dichlorvos.1.2 The scope <strong>of</strong> <strong>the</strong> context used to <strong>for</strong>m this assessment is confined to <strong>the</strong>documents listed in <strong>the</strong> Reference section <strong>of</strong> this document, <strong>the</strong> time constraints,<strong>the</strong> pr<strong>of</strong>essional experience <strong>of</strong> <strong>the</strong> author, and <strong>the</strong> date this document was issued.1.3 The assessment constitutes <strong>the</strong> whole document and <strong>the</strong> reference sources, andshould only be used as a whole.1.4 In spite <strong>of</strong> all care taken, <strong>the</strong> reference material should be directly consulted tocheck <strong>the</strong> veracity <strong>of</strong> data, opinions and o<strong>the</strong>r material used and attributed in thisdocument.1.5 No responsibility will be taken <strong>for</strong> misuse <strong>of</strong> this document, or use by thirdparties.Dichlorvos reassessment – application Page 278 <strong>of</strong> 436
CONTENTS:Title Page 11 Purpose 2Contents 32 <strong>Substance</strong> Identification 43 Activity Scenarios 54 Operator Exposure & Risk Assessment 85 Post-application or Re-entry Worker Exposures & Risk Assessment 336 Bystander & Resident Exposure & Risk Assessment 587 Summary & Conclusions 67References 74Appendix 1: Occupational Exposure Estimates & Risk Assessment withEngineering Controls 76Appendix 2: Occupational Exposure Estimates & Risk Assessment withRTU gas cylinders 79Appendix 3: Occupational Exposure Estimates & Risk Assessment <strong>for</strong> Spray<strong>Application</strong>s into Enclosed Spaces 86Appendix 4: Occupational Exposure Estimates & Risk Assessment <strong>for</strong> Spray<strong>Application</strong>s into Public Spaces 89Appendix 5: Re-entry Worker Exposure Estimate and Risk Assessment 92Appendix 6: Resident Exposures and Risk Assessment 94Last Page 103Dichlorvos reassessment – application Page 279 <strong>of</strong> 436
2SUBSTANCE IDENTIFICATIONIUPAC name:Chemical name (CAS):Common name:2,2-dichlorovinyl dimethylphosphate2,2-dichloroe<strong>the</strong>nyl dimethylphosphate; Phosphoric acid,2,2-dichloroe<strong>the</strong>nyl dimethyl esterDichlorvos; DDVPCAS Registry number: 62-73-7Molecular <strong>for</strong>mula: C 4 -H 7 -C l2 -O 4 -PMolecular weight: 220.97Structural <strong>for</strong>mula:(ChemID; HSG 18, 1988)Vapour pressure: 0.0158 mm Hg = 2.1 Pa (CCID, 2009)Dichlorvos reassessment – application Page 280 <strong>of</strong> 436
3ACTIVITY SCENARIOS3.1 Table (I) summarises <strong>the</strong> uses <strong>of</strong> dichlorvos from which occupational, bystanderand resident exposures and health risks have been estimated.Table I: Dichlorvos Use ScenariosScenario Crop/Use Method Rate <strong>Application</strong>sOutdoorEquipment Details Formu-lation<strong>Application</strong>rateArea orvolumetreatedNo. peryearInterval(days)1 Strawberries Low boom Fine – EC 800 20 ha 1 -mediumg a.i./ha2 droplet2 73 Vegetables, High boom Fine – EC 800 20 ha 1 -cereals,mediumg a.i./ha4 berriesdroplet2 75 FruitAirblast FinemediumEC 2052 8 ha 1 -6g a.i./haberry)(tamarillo/persimmons/droplet2 79 Glasshouse Automatic Fog RTU 0.05 25000 m 3 1 -crops/ applicationgas g/m 3 (1.25 ha)10mushrooms2 711 EC 1 -Fog12 2 713 Glasshouse Automatic Fog/low EC 1300 0.1 ha 1 -flowers application volumeg a.i./ha (2500 m 3 )14 (Cymbidium)mister2 77 Passionfruit Knapsack Finemediumg a.i./haEC 1026 1 ha 1 -8 droplet2 715 Hand held Finemediumg a.i./ha (5000 m 3 )EC 1800 0.2 ha 1 -sprayer16 droplet2 7Indoor17 Enclosed Automatic Fog RTU 0.05 & 0.15 375, 1 -space applicationgas g a.i./ m 3 3750 &18 (industrial)12500 2 7m 3 )19 Manual Fog RTU 0.05 & 0.151 -Foggergas g a.i./ m 3 2 720 Automatic Fog EC 0.05 & 0.151 -21applicationg a.i./ m 32 7Dichlorvos reassessment – application Page 281 <strong>of</strong> 436
Table I: Dichlorvos Use ScenariosScenario Crop/Use Method Rate <strong>Application</strong>sEquipment Details Formu-lation<strong>Application</strong>rateArea orvolumetreatedNo. peryearInterval(days)22 Manual Fog EC 0.05 & 0.151 -23foggerg a.i./ m 32 724 High Fine- EC 0.1 & 0.3 150, 1 -pressure mediumg a.i./ m 2 1500 &25 hand-wand droplet2500 m 2 2 7orequivalent26 Domestic use RTU Aerosol 3.1 0.25 g 7.44 m 2 1 -aerosol (manual g a.i./L a.i./m 227 )2 728 Knapsack FinemediumRTU 0.3 g a.i./m 2 60 m 2 1 -29liquida.i./L;4Lpack)droplet (4.4g2 7Outdoor – public space30 Public outdooruseManualfoggerFog EC 1500 ga.i./ha1 ha 1 -3.2 The occupational (work) activities <strong>for</strong> which exposure is estimated are mixing,loading (usually grouped, M/L) and application, toge<strong>the</strong>r termed operatorexposures, and workers entering <strong>the</strong> spray area after application, <strong>for</strong> example toweed or harvest <strong>the</strong> crop, termed post-application or re-entry activities.3.3 To estimate risks to operators at application and workers entering <strong>the</strong> sprayedareas post-application, exposures are predicted <strong>under</strong> likely use patterns, takinginto consideration <strong>the</strong> time worked, and <strong>the</strong> use <strong>of</strong> mitigation measures.3.4 During mixing, loading and application mitigation measures include: engineeringcontrols such as contained or closed mixing and loading systems, and closed cabswith or without filtered air supplies; Personal Protective Equipment (PPE); and/orRespiratory Protective Equipment (RPE).3.5 For workers post-application mitigation measures include: recommendations notto (re-)enter sprayed areas <strong>for</strong> set periods, or Restricted Entry Intervals (REI); PPEand/or RPE.3.6 For bystanders, risks to residents are only estimated from exposure <strong>of</strong> a child tosurfaces contaminated ei<strong>the</strong>r by being directly sprayed or from spray drift,because <strong>of</strong> concerns with model approaches <strong>for</strong> assessing direct exposures tospray drift or re-volatilised spray. In certain circumstances, such as workplaces,Dichlorvos reassessment – application Page 282 <strong>of</strong> 436
access <strong>of</strong> bystanders to treated areas can be restricted after application, but PPEand RPE cannot be considered as mitigation measures.3.7 Estimated exposures based on models are compared to <strong>the</strong> relevant health hazardbenchmark (Acceptable Operator Exposure Level, AOEL). The AOEL proposed<strong>for</strong> dichlorvos is 0.0014 mg/kg b.w./day [based on <strong>the</strong> NOAEL from <strong>the</strong> 28-dayhuman volunteer capsule (oral) study by Rider (1967 in APVMA, 2008a and USEPA, 2006a).]Dichlorvos reassessment – application Page 283 <strong>of</strong> 436
4OPERATOR EXPOSURE & RISK ASSESSMENT4.1 For occupational situations <strong>the</strong> main routes <strong>of</strong> exposure are assumed to be through<strong>the</strong> skin (dermal) or by inhalation. Ingestion <strong>of</strong> pesticide is not considered inoccupational estimates, as it should not occur in a trained work <strong>for</strong>ce. No separateassessment <strong>for</strong> multiple applications is necessary because <strong>the</strong> daily exposure isestimated and this is compared to <strong>the</strong> AOEL which takes into account that <strong>the</strong>worker may be exposed daily and allows <strong>for</strong> repeat exposure.4.2 As ERMA New Zealand has no actual exposure data measured in <strong>the</strong> field <strong>under</strong>New Zealand conditions, operator (mixer/loader/applicator) exposures wereestimated by TCL using <strong>the</strong> United Kingdom Chemicals Regulation Directorate(Pesticides)‘s (UK CRD, 1992) interpretation <strong>of</strong> <strong>the</strong> German BBA Model. Thederived values consider both dermal and inhalation exposure routes using <strong>the</strong>geometric mean exposure estimates.4.3 The BBA model calculates total systemic exposure or <strong>the</strong> total absorbed dosefrom both routes. The default assumption is that 100% <strong>of</strong> <strong>the</strong> inhaled material isabsorbed, and <strong>for</strong> dichlorvos this default value is used. However, estimation <strong>of</strong>dermal absorption (skin penetration) is usually more complex.4.4 After reviewing <strong>the</strong> available data, TCL used 30% as <strong>the</strong> proportion <strong>of</strong> dichlorvosthat would be absorbed from exposed skin <strong>for</strong> both concentrate and spray mix, inconcordance with <strong>the</strong> value used by APVMA, based on studies with rats (Jeffcoat,1990; Original not sighted in APVMA, 2008a). These data were also used by USEPA (2006a; 11%) and Cali<strong>for</strong>nian Department <strong>of</strong> Pesticide Regulation (CalDPR,1996; 13%), but <strong>the</strong>se regulators did not use <strong>the</strong> highest rate <strong>of</strong> absorption found,but an average.4.5 The BBA model allows exposure estimates to be made with and without a limitedrange <strong>of</strong> PPE and/or RPE <strong>for</strong> mixing/loading and application. Mixer/loaderexposures can be modelled with or without gloves, and with or without respirators(ei<strong>the</strong>r A1P2 or FFP2SL/P2 specification). Applicator exposures can be modelledwith or without head covering (hood + visor or broad-brimmed headgear), glovesand extra body covering (coverall + sturdy footwear), and respirators (ei<strong>the</strong>r A1P2or FFP2SL/P2 specification). Each item <strong>of</strong> PPE diminishes exposure to <strong>the</strong>covered part <strong>of</strong> <strong>the</strong> body by a set protective factor (i.e. allows a percentagetransmission). Similarly, <strong>the</strong> different RPE mitigate inhalation exposures by setprotective factors. [Note: For some scenarios o<strong>the</strong>r models have been used, suchas UK POEM 07, which may present different RPE/PPE options with possiblydifferent protective factors.] The risk assessment is done by calculating <strong>the</strong> RiskQuotient (RQ = estimated exposure/AOEL). If <strong>the</strong> RQ <strong>for</strong> a particular activity isunacceptable (RQ >1) <strong>the</strong>n fur<strong>the</strong>r exposure mitigation, such as engineeringcontrols, may be considered in <strong>the</strong> models.4.6 Contained or closed mixing and loading systems can be used, which reduce <strong>the</strong>dermal exposure to mixers/loaders while readying <strong>the</strong> application equipment <strong>for</strong>use. The US EPA considers that a correctly used and maintained closed systemDichlorvos reassessment – application Page 284 <strong>of</strong> 436
can reduce dermal exposures to mixer/loaders by 2.7 fold (a factor <strong>of</strong> 0.37)(Franklin & Worgan, 2005) [see Appendix 1].4.7 Enclosed cabs on motorised ground equipment can reduce <strong>the</strong> dermal, and if fittedwith appropriate filtered ventilation systems, inhalation exposures to applicatorsduring spraying. The US EPA considers that a correctly used and maintainedenclosed cab/filtration system can reduce exposures to applicators by 3 fold (afactor <strong>of</strong> 0.33) when using ground-booms and by 13.4 fold (0.075) with air-blastequipment (Franklin & Worgan, 2005) [see Appendix 1].4.8 Tables II, III, and IV show <strong>the</strong> modelled operator exposures and risks <strong>for</strong> <strong>the</strong>outdoor activities with dichlorvos based on <strong>the</strong> BBA model, with and without PPEand RPE, and with and without engineering controls (<strong>for</strong> Scenarios 1-4, 5 & 6).For Scenarios (7 & 8), that use hand-held sprayers, no enclosed cab is possibleand it has been assumed that no closed mixing and loading system would beavailable <strong>for</strong> such small quantities.4.9 Scenarios 9-14 where applications are indoors (greenhouses, mushroom houses) itis assumed that <strong>the</strong> application equipment is automatic or remote (i.e. applicatorsare not in <strong>the</strong> space being treated), so that occupational exposure is confined tomixer/loader, or in <strong>the</strong> case <strong>of</strong> gas products, connecting/disconnecting cylinders.4.10 The APVMA re-assessment (APVMA, 2008b) considered that operators might beexposed via <strong>the</strong> hands to dichlorvos when changing cylinders during gas fogging<strong>of</strong> glasshouse or mushroom houses (Scenarios 9 & 10). The APVMA estimateddermal exposure to 0.001 mL/cylinder (equivalent to 0.0014g dichlorvos, and with30% dermal absorption, a systemic dose <strong>of</strong> 0.00042g; glove penetration, 10%).Inhalation exposure could also result if some <strong>of</strong> <strong>the</strong> dichlorvos evaporated into <strong>the</strong>1m 3 personal air space around <strong>the</strong> operator‘s breathing zone. If 0.005ml <strong>of</strong>dichlorvos (wt. 7.1mg) was available <strong>for</strong> inhalation <strong>for</strong> 1 minute, <strong>the</strong>n <strong>the</strong>y wouldinhale 0.12mg or 0.0017 mg/kg b.w. (70kg) [see Appendix 2].4.11 In New Zealand, RTU gases are sold in 7 & 35L cylinders, containing 50g a.i./L;and are applied at use rates <strong>of</strong> 0.05g a.i./m 3 <strong>for</strong> volume fogging. The maximumcoverage per day is stated at 1.25ha (Scenarios 9 & 10), and assuming a 2.5mbuilding height, this would require approximately 1.6kg (31.25L <strong>of</strong> product) orfive 7L cylinders or one 35L.4.12 The fogging <strong>of</strong> glasshouses with EC dichlorvos solutions <strong>for</strong> crops or mushroomhouses (Scenarios 11 & 12) is modelled on use rates <strong>of</strong> 0.05g a.i./m 3 with amaximum coverage <strong>of</strong> 1.25ha (rate 1.25kg a.i./ha, assuming a 2.5m buildingheight) [Note: <strong>the</strong> product label also recommends use as a light spray, but Plant &Food Research reports that this is not done, and has not been modelled]. Thefogging <strong>of</strong> glasshouses <strong>for</strong> Cymbidium production (Scenarios 13 & 14) is stated tobe confined to 0.1ha per day, at a use rate <strong>of</strong> 1300 g/ha.4.13 Table V shows <strong>the</strong> modelled mixer/loader exposures and risks <strong>for</strong> <strong>the</strong> indooractivities with dichlorvos using remotely operated application equipment, withPPE and RPE (<strong>for</strong> Scenarios 9-14). The mixing loading exposure estimates <strong>for</strong>Scenarios 9 & 10 were based on <strong>the</strong> APVMA approach above. For Scenarios 11-Dichlorvos reassessment – application Page 285 <strong>of</strong> 436
14, <strong>the</strong> mixing/loading component <strong>of</strong> <strong>the</strong> BBA model was used. Since <strong>the</strong> BBAmodel does not include indoor scenarios, <strong>the</strong> outdoor equivalent (hand-heldsprayer: hydraulic nozzles – outdoor, high level target) has been used <strong>for</strong> <strong>the</strong>mixer/loader component.4.14 Table V also shows <strong>the</strong> modelled mixer/loader exposures and risks <strong>for</strong> <strong>the</strong> indooractivities with hand-held application equipment with dichlorvos (Scenarios 15 &16 - Cymbidium production; use rate: 1800g a.i./ha, with coverage confined to0.2ha/day) based on <strong>the</strong> BBA model, with PPE and RPE. Note <strong>the</strong> BBA modeldoes not include indoor scenarios nor application exposure <strong>for</strong> low level target, so<strong>the</strong> outdoor equivalent (hand-held sprayer: hydraulic nozzles – outdoor, high leveltarget) has been used to estimate <strong>the</strong> operator exposures. The outdoor scenariowill tend to <strong>under</strong> estimate exposure and risk, whereas <strong>the</strong> high level target willtend to over estimate exposure and risk.4.15 Scenarios 17-25 consider applications in enclosed (industrial) spaces. Some <strong>of</strong><strong>the</strong>se use automatic equipment, o<strong>the</strong>rs hand-held. In <strong>the</strong> <strong>for</strong>mer, occupationalexposure is confined to <strong>the</strong> mixer/loader, or in <strong>the</strong> case <strong>of</strong> gas products,connecting/disconnecting cylinders, as in <strong>the</strong> green- mushroom house scenarios.In <strong>the</strong> latter, both mixing/loading and application are included.4.16 In Scenarios 17 & 18 where RTU gas containing 50g a.i./L is triggered remotelyin enclosed spaces <strong>of</strong> 375, 3750 and 12,500 m 3 at use rates <strong>of</strong> 0.05g a.i./m 3 , 18.75,187.5 and 625g a.i. are required respectively <strong>for</strong> each space. These quantities <strong>of</strong>active are contained in 0.375, 3.75 and 12.5 L <strong>of</strong> gas, i.e. only one 7 L cylinderwould be needed <strong>for</strong> 375 and 3750, but two 7 L cylinders <strong>for</strong> 12,500 m 3 . Theproduct labels recommend a higher use rate <strong>of</strong> 0.15 g a.i./m 3 against certain pests.The higher rates would require 56.25, 562.5 and 975g a.i. respectively <strong>for</strong> <strong>the</strong>spaces: 375, 3750 and 12,500 m 3 . The APVMA estimated dermal exposure to0.001 mL/cylinder change (equivalent to 0.0014g dichlorvos, and with 30%dermal absorption, a systemic dose <strong>of</strong> 0.00042g; glove penetration, 10%), andinhalation exposure at 0.12 mg/cylinder change [see § 4.10 and Appendix 2]. Theresults are presented in Table VI.4.17 In Scenario 19 where RTU gas containing 50g a.i./L is applied using a manualpressure gun in enclosed spaces <strong>of</strong> 375, 3750 and 12,500 m 3 at use rates <strong>of</strong> 0.05ga.i./m 3 , <strong>the</strong> exposure calculated in § 4.15 <strong>for</strong> cylinder handling is added to thatduring application.4.18 The APVMA (2008b) noted that operators were directed to work away from spraydrift and towards <strong>the</strong> exit, and avoiding wetting any surfaces. The pressure nozzlewas likely to be held at chest or head height. Dichlorvos volatilisation would bealmost instantaneous and complete on ejection from <strong>the</strong> nozzle.4.19 The APVMA used a Pesticide Handlers Exposure Database (PHED) exposuremodel <strong>for</strong> high pressure handwand application, in <strong>the</strong> absence <strong>of</strong> any suitablePOEM model (<strong>the</strong>ir preferred option). The PHED model was modified to address<strong>the</strong> expectation that <strong>the</strong> efflux from a manual pressure gun would be significantlyless diffuse and more directional, to estimate dermal exposures during enclosedspace applications. Head/neck, exterior <strong>of</strong> clothing and hands were assumed to beDichlorvos reassessment – application Page 286 <strong>of</strong> 436
contaminated with, respectively 0.018, 2.68 and 0.26 mg/kg active handled, 10%<strong>of</strong> <strong>the</strong> values from <strong>the</strong> PHED high pressure handwand model [See Appendix 2].Without actual exposure data while using manual pressure guns, <strong>the</strong> estimatesbased on <strong>the</strong> modified PHED model must be seen as uncertain. The APVMAapproach used PPE choices <strong>of</strong>: none; overalls with 20% penetration; or, achemical resistant full-body suit that also covered <strong>the</strong> head, 5% penetration; and,gloves with 10% penetration (APVMA, 2008b). These PPE choices andpenetration factors were used in <strong>the</strong> scenarios 19-25 (see Tables VII and VIII), butonly <strong>the</strong> minimum PPE/RPE required to achieve an acceptable risk are generallytabulated.4.20 For <strong>the</strong> estimation <strong>of</strong> inhalation exposures APVMA noted, in <strong>the</strong> absence <strong>of</strong> anysuitable POEM or PHED models, that as long as <strong>the</strong> operator did not walk backthrough <strong>the</strong> efflux stream <strong>the</strong>n <strong>the</strong> highest airborne concentration <strong>of</strong> dichlorvosshould be <strong>the</strong> use rate, 50 mg/m 3 , with a TWA <strong>of</strong> 25 mg/m 3 . The APVMAestimated <strong>the</strong> duration <strong>of</strong> exposure on <strong>the</strong> application times from <strong>the</strong>manufacturer‘s specification <strong>for</strong> <strong>the</strong> manual pressure gun [see Appendix 2]. Thus<strong>the</strong> exposure times were rounded to 1.5, 15 and 50 minutes respectively. Theresults are presented in Table VI. The APVMA approach used RPE choices <strong>of</strong>:none; half-face respirator with 10% penetration; full-face respirator, 2%penetration; or, air-hose/Self-Contained Breathing Apparatus (SCBA) with 0%penetration (APVMA, 2008b). These RPE choices and penetration factors wereused in <strong>the</strong> scenarios 19-25 (see Tables VII and VIII), but only <strong>the</strong> minimumPPE/RPE required to achieve an acceptable risk are generally tabulated.4.21 In Scenarios 20 and 21 a fogging solution is triggered remotely into enclosedspaces <strong>of</strong> 375, 3750 and 12,500 m 3 . Based on a <strong>for</strong>mulation containing 1000ga.i./L and applied at 5 ml/100m 3 (i.e. a use rate <strong>of</strong> 0.05g a.i./m 3 ), 18.75, 187.5 and625g a.i. are required respectively to treat each space. The product labelsrecommend a higher use rate <strong>of</strong> 0.15 g a.i./m 3 against certain pests. The higherrates would require 56.25, 562.5 and 975g a.i. respectively <strong>for</strong> <strong>the</strong> spaces: 375,3750 and 12,500 m 3 .4.22 The modelled mixer/loader exposures and risks <strong>for</strong> <strong>the</strong> indoor activities withdichlorvos were based on <strong>the</strong> BBA model, with PPE and RPE. At a use rate <strong>of</strong>0.05g a.i./m 3 and an active concentration <strong>of</strong> 1000g a.i./L, 1.25L product/ha(assuming a 2.5m building height); work rate, 0.015 ha per day <strong>for</strong> 375 m 3 , 0.15ha per day <strong>for</strong> 3750 m 3 , 0.5 ha per day <strong>for</strong> 12,500 m 3 . At <strong>the</strong> higher rate <strong>of</strong> 0.15ga.i./m 3 , <strong>the</strong> work rates are <strong>the</strong> same, but 3.75L product/ha. Note <strong>the</strong> BBA modeldoes not include indoor scenarios, so <strong>the</strong> outdoor equivalent (hand-held sprayer:hydraulic nozzles – outdoor, high level target) has been used <strong>for</strong> <strong>the</strong> mixer/loadercomponent [see Table VII].4.23 In Scenarios 22 and 23 <strong>the</strong> fogger solution is applied manually into enclosedspaces <strong>of</strong> 375, 3750 and 12,500 m 3 (equivalent areas: 150, 1500 and 2500 m 2 ;APVMA, 2008b: assumes 2.5m building height) at use rates <strong>of</strong> 0.05g a.i./m 3 . TheAPVMA considered <strong>the</strong> same Pesticide Handlers Exposure Database (PHED)exposure model <strong>for</strong> high pressure handwand application, modified to address <strong>the</strong>expectation that <strong>the</strong> efflux from a manual pressure gun would be significantly lessdiffuse and more directional, suitable to estimate dermal exposures duringDichlorvos reassessment – application Page 287 <strong>of</strong> 436
enclosed space applications. Head/neck, exterior <strong>of</strong> clothing and hands wereassumed to be contaminated with, respectively 0.018, 2.68 and 0.26 mg/kg activehandled, 10% <strong>of</strong> <strong>the</strong> values from <strong>the</strong> PHED high pressure handwand model [seeAppendix 2]. Without actual exposure data while using high pressure handwands,<strong>the</strong> estimates based on <strong>the</strong> modified PHED model must be seen as uncertain.4.24 For inhalation exposure from manually applied fogger solutions, <strong>the</strong> sameapproach as used <strong>for</strong> estimating applicator exposures from RTU gas is used [see §4.20 and Appendix 2] [see Table VII].4.25 In Scenarios 24 and 25 where a spray is manually applied into enclosed areas <strong>of</strong>150, 1500 and 2500 m 2 (equivalent spaces: 375, 3750 and 12,500 m 3 ) at a use rate<strong>of</strong> 0.1 and 0.3g a.i./m 2 . The APVMA considered <strong>the</strong> PHED model 35(mixer/loader/applicators mixing liquid <strong>for</strong>mulations by open pour methods andapplying <strong>the</strong> spraymix with high pressure handwand) <strong>the</strong> most appropriateestimation method. The predicted dermal exposure rates on head, body and handswere respectively 1.155, 90.86 and 2.49 mg a.i./kg applied. The spaces 150, 1500and 2500 m 2 would require: 15, 150 and 250g a.i. to be handled and applied at <strong>the</strong>use rate <strong>of</strong> 0.1g a.i./m 2 . A higher application rate <strong>of</strong> 0.30g a.i./m 2 is recommended<strong>for</strong> <strong>the</strong> control <strong>of</strong> cockroaches, fleas etc., and <strong>the</strong> spaces would <strong>the</strong>n require: 45,450 and 750g a.i. to be handled and applied. [See Appendix 3]4.26 For inhalation exposures from using high pressure handwand equipment indoors,APVMA modified <strong>the</strong> most relevant PHED model to account <strong>for</strong> <strong>the</strong> highvolatility <strong>of</strong> dichlorvos and estimated an inhalation exposure rate <strong>of</strong> 13.2 mga.i./kg applied [50 fold increase to account <strong>for</strong> <strong>the</strong> higher volatility, but also <strong>the</strong>slower volatilisation and greater droplet precipitation <strong>of</strong> an aerosol compared to aCO 2 pressure gun efflux] [See Appendix 3 and Table VIII].4.27 In Scenarios 26 and 27 RTU gas is applied manually in a domestic enclosed spaceas a surface/crevice application <strong>for</strong> <strong>the</strong> control <strong>of</strong> cockroaches, ants, fleas,silverfish, carpet beetles etc. at a use rate <strong>of</strong> 0.25g a.i./m 2 . In New Zealand <strong>the</strong>available product is sold in 600mL cans with 3.1g dichlorvos/L (P03653 label,BV2 Surface Insecticide). Each can contains 1.86 g dichlorvos enough <strong>for</strong> 7.44m 2at <strong>the</strong> recommended use rate above, although <strong>the</strong> label does not provide a specificapplication rate.4.28 The UK CRD (Model, 2006; Guidance document, 2008c) have models availableto estimate exposures during amateur use <strong>of</strong> pesticides, including a data-basedAerosol Surface treatment model. The model assumes rates <strong>of</strong> dermal (hand and<strong>for</strong>earm; 0.0647 mL/min; legs, feet and face: 0.0357 mL/min) and inhalationexposure per minute taken <strong>for</strong> <strong>the</strong> task (0.0006 mL/min), with a default duration<strong>of</strong> 300 seconds (5 minutes). The models rely on 15 sets <strong>of</strong> data from twoexposure monitoring studies during tasks such as spraying a small room includings<strong>of</strong>a, 6 metres <strong>of</strong> skirting board, 2 dining chairs, and 6 m 2 <strong>of</strong> carpet. 5 minutescould seem a long time to discharge a 600mL can, but if <strong>the</strong> total time in <strong>the</strong>treated room(s) is considered with <strong>the</strong> time needed to spray s<strong>of</strong>a cushions andmore complex items <strong>the</strong>n it would be a realistic assumption. Given that <strong>the</strong>re isno application rate on <strong>the</strong> label <strong>the</strong> modelling will be very approximate.Dichlorvos reassessment – application Page 288 <strong>of</strong> 436
The modelling is based upon discharge over a period <strong>of</strong> 5 minutes <strong>of</strong> a 600mLRTU can containing 3.1 g a.i/L (P03653 label, BV2 Surface Insecticide); dermalabsorption, 30%; inhalation absorption, 100%. Predicted exposures (75 thpercentile values) from Scenarios 26 and 27 with <strong>the</strong> RQ values are shown inTable IX.4.29 Scenarios 28 & 29 envisage amateur users loading a ready to use (RTU)dichlorvos spray solution into a knapsack sprayer <strong>for</strong> applications to larger areas,such as patios and decks. The registered product (P03915, BV2 SurfaceInsecticide Bulk) contains 4.4g dichlorvos/L, and is sold in 4L packs (containing17.6g a.i. in total). No application rate is recommended beyond <strong>the</strong> labelstatement that treated surfaces should be damp. This is essentially <strong>the</strong> same asScenarios 24 and 25 [§ 4.25], except <strong>for</strong> amateur instead <strong>of</strong> pr<strong>of</strong>essional users, andwhere no PPE or RPE can be expected but smaller areas would be treated. Formodelling it is assumed that <strong>the</strong> complete 4L pack is used in one session, but <strong>the</strong>available models require an application rate <strong>for</strong> calculations. The pr<strong>of</strong>essionalproducts (Scenarios 24 & 25, § 4.25) recommended application rates <strong>of</strong> 0.30ga.i./m 2 <strong>for</strong> <strong>the</strong> control <strong>of</strong> similar pests, cockroaches, fleas etc. At 0.30g a.i./m 2 , 4L<strong>of</strong> product containing 4.4 g/L would cover approximately 60m 2 (17.6 / 0.3).Given that <strong>the</strong>re is no application rate on <strong>the</strong> label <strong>the</strong> modelling will be veryapproximate.4.30 The UK CRD‘s POEM_07 (UK CRD, 2007) has models available to estimateexposures during amateur use <strong>of</strong> pesticides through knapsack sprayers (5L),which <strong>the</strong> BBA model does not, so this model was used <strong>for</strong> this application. Themodel accepts that hand contamination may be higher than <strong>for</strong> pr<strong>of</strong>essional users.The model also requires inputs <strong>for</strong> mixing/loading. The worst-case <strong>for</strong> handcontamination during mixing / loading is posed by containers with separatemeasuring caps, and <strong>the</strong> least exposure using an "integral squeeze-to-fillmeasure". Since, <strong>the</strong> RTU product involves no measuring only loading <strong>the</strong> lowestexposure option was used. The default assumptions are that <strong>the</strong> operator uses nogloves, wears a T-shirt and shorts, and exposure lasts <strong>for</strong> 30 minutes. However,since only 4L <strong>of</strong> <strong>the</strong> RTU product is to be applied 15 minutes has been used as anupper limit <strong>for</strong> <strong>the</strong> time needed to spray 4L in place <strong>of</strong> this default setting.4.31 The exposures (75 th percentile values) from Scenarios 28 and 29 with <strong>the</strong> RQvalue are shown in Table IX.4.32 For Scenario 30, fogging <strong>of</strong> public spaces, <strong>the</strong> Nuvos label (P001132) describes<strong>the</strong> use as covering parks, beaches, sports areas and o<strong>the</strong>r fly breeding sites <strong>for</strong> <strong>the</strong>control <strong>of</strong> fly larvae and mosquitoes by applying a cold fog to wet <strong>the</strong> top 5-8cm<strong>of</strong> litter. The use rate is taken to be 10ml product/ 2L spraymix/ 100m 2 , based on<strong>the</strong> area coverage advised <strong>for</strong> o<strong>the</strong>r applications, and as Nuvos contains 1000gdichlorvos/L this is 0.1g a.i./m 2 . For similar uses, APVMA (2008b) estimatedexposures and risks from spraying 1 or 5 ha/day.4.33 The APVMA considered <strong>the</strong> PHED model 3 (mixer/loader mixing liquid<strong>for</strong>mulations by open pour methods) <strong>the</strong> most appropriate estimation method <strong>for</strong>predicting dermal and inhalation exposures. The predicted dermal exposure rateson head, body and hands were respectively 0.0116, 0.6622 and 6.248 mg a.i./kgDichlorvos reassessment – application Page 289 <strong>of</strong> 436
handled. The APVMA considered that <strong>the</strong> predicted rate <strong>of</strong> inhalation exposurewould be significantly <strong>under</strong>estimated <strong>for</strong> dichlorvos due to its high volatility.Utilising data from one study (Gold & Holcslaw, 1984; Original not sighted), <strong>the</strong>APVMA increased <strong>the</strong> predicted rate <strong>of</strong> inhalation exposure by 50-fold to give0.132 mg a.i./kg handled.4.34 The APVMA used <strong>the</strong> data-based PHED model 19 to predict exposures duringapplication. The predicted dermal exposure rates on head, body and hands wererespectively 0.184, 26.8 and 2.55 mg a.i./kg handled, while <strong>the</strong> predictedinhalation exposure rate was 0.174 mg a.i./kg handled. See Table X andAppendix 4 <strong>for</strong> predicted exposures from 1 hectare applications.Dichlorvos reassessment – application Page 290 <strong>of</strong> 436
Table II: Occupational Exposure Estimates & Risk Assessment aScenarios (1-4): Tractor mounted/trailed boom sprayer: hydraulic nozzlesOperation / RPE / PPE<strong>Application</strong>Rate(kg a.i./ha)Work Rate(ha)Dermalabsorbed dose(mg/day) bInhalationabsorbed dose(mg/day) bTotal operatorsystemic exposure(mg/kg b.w./day) bRiskQuotient(RQ) cScenario 1-4: Boom sprayer with engineering controlsMixing/loading: Mechanical transfer system d(Mixing/loading: A1P2 + gloves<strong>Application</strong>: Enclosed cab with appropriate filtration system e(<strong>Application</strong>: overalls + boots + gloves0.8 20 0.04260.11520.22780.6902Mixing/loading: A1P2 + gloves0.8 20 0.1152<strong>Application</strong>: Enclosed cab with appropriate filtration system e 0.2278Mixing/loading: Mechanical transfer system d<strong>Application</strong>: A1P2 + hood/visor + overalls + boots + glovesScenario 1-4: Boom sprayer without engineering controlsMixing/loading: A1P2 + gloves<strong>Application</strong>: A1P2 + hood/visor + overalls + boots + glovesMixing/loading: gloves<strong>Application</strong>: hood/visor + overalls + boots + glovesMixing/loading: gloves<strong>Application</strong>: glovesMixing/loading: no PPE<strong>Application</strong>: no PPE0.8 20 0.04260.41380.8 20 0.11520.41380.8 20 0.11520.41660.8 20 0.11520.8 20 128100.00020.0002)0.00530.016)0.00020.00530.00020.00030.00020.00030.00960.0160.00960.0160.00960.016) 0.0039) 2.8) 0.00503.6)) 0.00664.7)) 0.00765.4)) 0.00805.7)) 0.116183)) 0.3048218)Dichlorvos reassessment – application Page 291 <strong>of</strong> 436
abcdeUK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model using geometric mean estimates – a.s. concentration, 1000 g/L; dose, 0.8L product/ha; default RPE/PPE options;Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;Assumes a reduction <strong>of</strong> dermal exposures to mixer/loaders by 2.7x when only a single layer <strong>of</strong> clo<strong>the</strong>s and gloves were worn (protection factor, x 0.37) [using dermalexposure data <strong>for</strong> A1P2 + gloves (0.1152) as base-line: 0.1152 x 0.37 = 0.0426];Assumes a reduction <strong>of</strong> dermal and inhalation exposures to boom-sprayer applicators by 3x when only a single layer <strong>of</strong> clo<strong>the</strong>s and gloves were worn (protection factor, x0.33) [using dermal exposure data <strong>for</strong> overalls + boots + gloves (0.6902) and inhalation exposure (0.016) as base-line: 0.6902 x 0.33 = 0.2278; 0.016 x 0.33 = 0.0053].Dichlorvos reassessment – application Page 292 <strong>of</strong> 436
Table III: Occupational Exposure Estimates & Risk Assessment aScenarios (5 & 6): Tractor mounted/trailed broadcast air-assisted sprayerOperation / RPE / PPE<strong>Application</strong>Rate(kg a.i./ha)Work Rate(ha)Dermalabsorbed dose(mg/day) bInhalationabsorbed dose(mg/day) bTotal operatorsystemic exposure(mg/kg b.w./day) bRiskQuotient(RQ) cScenario 5 & 6: Broadcast air-assisted sprayer with engineering controlsMixing/loading: Mechanical transfer system d(Mixing/loading: A1P2 + gloves<strong>Application</strong>: Enclosed cab with appropriate filtration system e(<strong>Application</strong>: overalls + boots + gloves2.052 8 0.04370.11820.62318.3081Mixing/loading: A1P2 + gloves2.052 8 0.1182<strong>Application</strong>: Enclosed cab with appropriate filtration system e 0.6231Mixing/loading: Mechanical transfer system d<strong>Application</strong>: A1P2 + hood/visor + overalls + boots + glovesScenario 5 & 6: Broadcast air-assisted sprayer without engineering controlsMixing/loading: A1P2 + gloves<strong>Application</strong>: A1P2 + hood/visor + overalls + boots + glovesMixing/loading: gloves<strong>Application</strong>: hood/visor + overalls + boots + glovesMixing/loading: gloves<strong>Application</strong>: gloves2.052 8 0.04372.63482.052 8 0.11822.63482.052 8 0.11822.69392.052 8 0.1182530.00020.0002)0.02220.2955)0.00020.02220.00020.00590.00020.00590.00990.29550.00990.2955) 0.0098) 7) 0.0109)) 0.0384)) 0.0394)) 0.0445)) 0.7664Mixing/loading: no PPE 2.052 8 12 0.0099 ) 0.9823 702)8272832547Dichlorvos reassessment – application Page 293 <strong>of</strong> 436
<strong>Application</strong>: no PPE 57 0.2955 )abcUK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model using geometric mean estimates – a.s. concentration, 1140 g/L; dose, 1.8L product/ha; default RPE/PPE options;Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;deAssumes a reduction <strong>of</strong> dermal exposures to mixer/loaders by 2.7x when only a single layer <strong>of</strong> clo<strong>the</strong>s and gloves were worn (protection factor, x 0.37) [using dermalexposure data <strong>for</strong> A1P2 + gloves (0.1182) as base-line: 0.1182 x 0.37 = 0.0437];Assumes a reduction <strong>of</strong> dermal and inhalation exposures to air-blast applicators by 13.4x when only a single layer <strong>of</strong> clo<strong>the</strong>s and gloves were worn (protection factor, x0.075) [using dermal exposure data <strong>for</strong> overalls + boots + gloves (8.3081) and inhalation exposure (0.2955) as base-line: 8.3081 x 0.075 = 0.6231; 0.2955 x 0.075 = 0.0222].Dichlorvos reassessment – application Page 294 <strong>of</strong> 436
Operation / RPE / PPETable IV: Occupational Exposure Estimates & Risk Assessment aScenarios (7 & 8): Hand-held sprayer: hydraulic nozzles. Outdoor, high level target<strong>Application</strong>Rate(kg a.i./ha)Work Rate(ha)Dermalabsorbed dose(mg/day) bInhalationabsorbed dose(mg/day) bTotal operatorsystemic exposure(mg/kg b.w./day) bRiskQuotient(RQ) cMixing/loading: A1P2 + gloves<strong>Application</strong>: A1P2 + hood/visor + overalls + boots + glovesMixing/loading: gloves<strong>Application</strong>: hood/visor + overalls + boots + glovesMixing/loading: gloves<strong>Application</strong>: glovesMixing/loading: no PPE<strong>Application</strong>: no PPEabc1.026 1 0.63100.47651.026 1 0.63100.49131.026 1 0.63109.20511.026 1 63120.00100.00620.05130.30780.05130.30780.05130.3078) 0.0159)) 0.0212)) 0.1457)) 1.0842UK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model using geometric mean estimates – a.s. concentration, 1140 g/L; dose, 0.9L product/ha; default RPE/PPE options;Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;)1115104774Dichlorvos reassessment – application Page 295 <strong>of</strong> 436
Table V: Occupational Exposure Estimates & Risk AssessmentScenarios (9-16): Glass- Mushroom house <strong>Application</strong>sOperation / RPE / PPE<strong>Application</strong>Rate(kg a.i./ha)Work Rate(ha)Dermalabsorbed dose(mg/day) aInhalationabsorbed dose(mg/day) aTotal operatorsystemic exposure(mg/kg b.w./day) aRiskQuotient(RQ) bScenario 9 & 10: Glass- mushroom house fogging using RTU gas cylinders with automatic/remote application (exposure only at cylinder connection/disconnection)Scenario (9 & 10) Five 7L cylinders: Mixing/loading: gloves cMixing/loading: Air-hose/SCBA respirator + glovesScenario (9 & 10) One 35L cylinder: Mixing/loading: gloves cMixing/loading: Half-face respirator + gloves1.25 1.25 0.210.211.25 1.25 0.042Scenario 11 & 12: Glass- mushroom house fogging using EC <strong>for</strong>mulations with automatic/remote application (exposure only during mixing/loading)Scenario (11 & 12) Mixing/loading: A1P2 + gloves d 1.25 1.25 0.9609 0.0016 0.0138 9.8Scenario 13 & 14: Glasshouse (Cymbidium) fogging using EC <strong>for</strong>mulations with automatic/remote application (exposure only during mixing/loading)Scenario (13 & 14) Mixing/loading: A1P2 + gloves e 1.3 0.1 0.080 0.0001 0.0011 0.8Scenario 15 & 16: Glasshouse (Cymbidium) fogging using EC <strong>for</strong>mulations with manual applicationScenario (15 & 16) Mixing/loading: A1P2 + gloves f<strong>Application</strong>: A1P2 + hood/visor + overalls + boots + glovesabcd0.0421.8 0.2 0.22140.16720.6nil0.120.0120.00040.0022Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;0.01160.0030.00230.0008) 0.0056RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;APVMA assumptions (2008): dermal exposure, 0.001 mL/cylinder change (equivalent to 0.0014g dichlorvos, and with 30% dermal absorption, a systemic dose <strong>of</strong> 0.00042g;glove penetration, 10%); inhalation exposure, 0.12 mg/cylinder change;UK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model – geometric means: hand-held sprayer: hydraulic nozzles – outdoor, low level target; a.s. concentration, 1000 g/L; dose,)8.32.11.70.64Dichlorvos reassessment – application Page 296 <strong>of</strong> 436
1.25L product/ha; work rate, 1.25 ha per day; default RPE/PPE options;eUK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model – geometric means: hand-held sprayer: hydraulic nozzles – outdoor, high level target; a.s. concentration, 1000 g/L; dose,1.3L product/ha; work rate, 0.1 ha per day; default RPE/PPE options;fUK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model – geometric means: hand-held sprayer: hydraulic nozzles – outdoor, high level target; a.s. concentration, 1000 g/L; dose,1.8L product/ha; work rate, 0.2 ha per day; default RPE/PPE options.Dichlorvos reassessment – application Page 297 <strong>of</strong> 436
Table VI: Occupational Exposure Estimates & Risk AssessmentScenarios (17-19): Enclosed Space Fogging <strong>Application</strong>s with RTU GasOperation / RPE / PPE<strong>Application</strong>Rate(g a.i./m 3 )VolumeTreated(m 3 )Dermalabsorbed dose(mg/day) aInhalationabsorbed dose(mg/day) aTotal operatorsystemic exposure(mg/kg b.w./day) aRiskQuotient(RQ) bScenario 17 & 18: Enclosed space fogging using RTU gas cylinders with automatic/remote application (exposure only at cylinder connection/disconnection)One 7L cylinder: Mixing/loading: gloves cMixing/loading: Half-face respirator + glovesTwo 7L cylinders: Mixing/loading: Half-face respirator + gloves cMixing/loading: Full-face RPE + glovesScenario 19: Enclosed space fogging using RTU gas cylinders with manual applicationMixing/loading: Half-face respirator + gloves c<strong>Application</strong>: No PPE0.05 375, 3750 0.0420.0420.05 12,500 0.0840.05 375(1.5 minexposure,one 7Lcylinder)Mixing/loading: Half-face respirator + gloves c0.05 3750<strong>Application</strong>: Full-face RPE + chem. resistant full-body + boots +(15 mingloves dexposure,one 7L<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +gloves d cylinder)Mixing/loading: Full-face respirator + gloves c0.05 12,500gloves d exposure;<strong>Application</strong>: Full-face RPE + chem. resistant full-body + boots +(50 min0.0840.0420.01670.0420.00910.00910.0840.03020.120.0120.0240.00480.0120.00890.0120.125nil0.00480.4167)0.00230.00080.00150.00131.70.61.10.9) 0.0011 0.8)) 0.0027or 0.0001)1.90.1) 0.0077 6Dichlorvos reassessment – application Page 298 <strong>of</strong> 436
<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +gloves dabctwo 7Lcylinders)Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;0.0302 nil or 0.0017 1.2RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;APVMA assumptions (2008): dermal exposure, 0.001 mL/cylinder change (equivalent to 0.0014g dichlorvos, and with 30% dermal absorption, a systemic dose <strong>of</strong> 0.00042g;glove penetration, 10%); inhalation exposure, 0.12 mg/cylinder change;dP <strong>for</strong> PPE (% penetration): none, 1 (100%); overalls, 0.2 (20%); chemical resistant full-body suit, 0.05 (5%); gloves, 0.1 (10%);P <strong>for</strong> RPE (% penetration): none, 1 (100%); half-face respirator, 0.1 (10%); full-face, 0.02 (2%); air-hose/SCBA, nil exposure (0%) (Thongsinthusak et al., 1993 in APVMA,2008b).Dichlorvos reassessment – application Page 299 <strong>of</strong> 436
Table VII: Occupational Exposure Estimates & Risk AssessmentScenarios (20-23): Enclosed Space <strong>Application</strong>s with EC SolutionsOperation / RPE / PPE<strong>Application</strong>Rate(g a.i./m 3 )VolumeTreated(m 3 )Dermalabsorbed dose(mg/day) aInhalationabsorbed dose(mg/day) aTotal operatorsystemic exposure(mg/kg b.w./day) aRiskQuotient(RQ) bScenario 20 & 21: Enclosed space fogging using EC solutions with automatic/remote application (exposure only at mixing/loading)Mixing/loading: A1P2 + gloves cMixing/loading: A1P2 + glovesMixing/loading: A1P2 + glovesMixing/loading: A1P2 + gloves dMixing/loading: A1P2 + glovesMixing/loading: A1P2 + gloves0.05 375375012,5000.15 375Scenario 22 & 23: Enclosed space fogging using EC solutions with manual applicationMixing/loading: A1P2 + gloves c375012,5000.01150.11530.38440.03460.34591.1531<strong>Application</strong>: Half-face RPE + overalls + gloves e 0.00330.05 375 0.0115Mixing/loading: A1P2 + gloves c0.05 3750 0.1153<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +0.0091Mixing/loading: A1P2 + gloves c0.05 12,500 0.3844<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +0.03020.000020.00020.00060.000060.00060.00190.000020.00090.0002nil0.0006nil0.00020.00170.00550.00050.00500.0165) 0.0002)) 0.0018)) 0.0059Mixing/loading: A1P2 + gloves d 0.15 375 0.0346 0.00006 ) 0.0007 0.5)0.11.23.90.43.690.11.34.2Dichlorvos reassessment – application Page 300 <strong>of</strong> 436
<strong>Application</strong>: Half-face RPE + overalls + gloves e 0.0099 0.0027 )Mixing/loading: A1P2 + gloves d0.15 3750 0.3459<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +0.02720.0006nil) 0.0053)3.8Mixing/loading: A1P2 + gloves d0.15 12,500 1.1531<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +0.0905abcde0.0019Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;nil) 0.0178RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;UK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model (mixing/loading component) – geometric means: hand-held sprayer: hydraulic nozzles – outdoor, high level target; a.s.concentration, 1000 g/L; dose, 1.25L product/ha; default RPE/PPE options;UK CRD interpretation <strong>of</strong> <strong>the</strong> German BBA Model (mixing/loading component) – geometric means: hand-held sprayer: hydraulic nozzles – outdoor, high level target; a.s.concentration, 1000 g/L; dose, 3.75L product/ha; default RPE/PPE options;APVMA modification <strong>of</strong> <strong>the</strong> PHED model <strong>for</strong> high pressure handwand application: P <strong>for</strong> PPE (% penetration): none, 1 (100%); overalls, 0.2 (20%); chemical resistant fullbodysuit, 0.05 (5%); gloves, 0.1 (10%);P <strong>for</strong> RPE (% penetration): none, 1 (100%); half-face respirator, 0.1 (10%); full-face, 0.02 (2%); air-hose/SCBA, nil exposure (0%) (Thongsinthusak et al., 1993 in APVMA,2008b).)13Dichlorvos reassessment – application Page 301 <strong>of</strong> 436
Operation / RPE / PPETable VIII: Occupational Exposure Estimates & Risk AssessmentScenarios (24-25): Enclosed Space <strong>Application</strong>s <strong>of</strong> EC Solutions with High Pressure Hand-wand a<strong>Application</strong>Rate(g a.i./m 2 )AreaTreated(m 2 )Dermalabsorbed dose(mg/day) bInhalationabsorbed dose(mg/day) bTotal operatorsystemic exposure(mg/kg b.w./day) bRiskQuotient(RQ) cMixing/loading/<strong>Application</strong> (Dermal): Chem. resistant full-body 0.1 150 0.0218Mixing/loading/<strong>Application</strong> (Inhalation): Half-face RPE d+ boots + gloves dMixing/loading/<strong>Application</strong> (Dermal): Chem. resistant full-body 0.1 1500 0.2182Mixing/loading/<strong>Application</strong> (Inhalation): Air-hose RPE d+ boots + gloves dMixing/loading/<strong>Application</strong> (Dermal): Chem. resistant full-body 0.1 2500 0.3638Mixing/loading/<strong>Application</strong> (Inhalation): Air-hose RPE d+ boots + gloves dMixing/loading/<strong>Application</strong> (Dermal): Chem. resistant full-body 0.3 150 0.0655Mixing/loading/<strong>Application</strong> (Inhalation): Air-hose RPE d+ boots + gloves dabcd-----0.0198-nil-nil-nil) 0.0006)) 0.0031)) 0.0052)) 0.0009APVMA modifications <strong>of</strong> PHED models (mixer/loader/applicators mixing liquid <strong>for</strong>mulations by open pour methods and applying <strong>the</strong> spraymix with high pressurehandwand)[Note: unlike <strong>the</strong> o<strong>the</strong>r models this assesses mixer/loader/applicators toge<strong>the</strong>r, not M/L + A as above];Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;P <strong>for</strong> PPE: none, 1 (100%); overalls, 0.2 (20%); chemical resistant full-body suit, 0.05 (5%); gloves, 0.1 (10%);)0.4240.7Dichlorvos reassessment – application Page 302 <strong>of</strong> 436
P <strong>for</strong> RPE (% penetration): none, 1 (100%); half-face respirator, 0.1 (10%); full-face, 0.02 (2%); air-hose/SCBA, nil exposure (0%) (Thongsinthusak et al., 1993 in APVMA,2008b).Dichlorvos reassessment – application Page 303 <strong>of</strong> 436
Table IX: Residential Exposure Estimates & Risk AssessmentOperation<strong>Application</strong>Rate(g a.i./m 2 )AreaTreated(m 2 )Dermalabsorbed dose(mg/day) aInhalationabsorbed dose(mg/day) aTotal operatorsystemic exposure(mg/kg b.w./day) aRiskQuotient(RQ) bScenarios (26-27): Enclosed Space <strong>Application</strong>s <strong>of</strong> RTU Gas Cans c<strong>Application</strong>: 0.25 7.44 0.4669 0.0093 0.0068 4.9Scenarios (28-29): Surface/Crevice <strong>Application</strong>s <strong>of</strong> RTU Spray-mixes dLoading:0.3 60 0.0132nil0.1530 109<strong>Application</strong>:abcd10.6755Assumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;UK CRD (2006 & 2008c) models <strong>for</strong> amateur use: Aerosol Surface Treatment model – 75 th percentile values; one 600mL can containing 3.1g a.i./L; default exposure time <strong>of</strong>5 minutes; no PPE/RPE; 70kg b.w. is used instead <strong>of</strong> <strong>the</strong> default 60kg;UK CRD (2007) POEM-07 model <strong>for</strong> amateur use: Knapsack Sprayers (5L) using "integral squeeze-to-fill measure" (lowest rate <strong>of</strong> contamination as no mixing is requiredwith a RTU) – 75 th percentile values; a.s. concentration, 4.4 g/L; dose & application volume both at 683 L/ha; default exposure time <strong>of</strong> 15 minutes; no PPE/RPE; 70kg b.w.is used instead <strong>of</strong> <strong>the</strong> default 60kg.0.022Dichlorvos reassessment – application Page 304 <strong>of</strong> 436
Table X: Occupational Exposure Estimates & Risk AssessmentScenario (30): Public Space Manual Fogging <strong>Application</strong>s – 1 hectareOperation / RPE / PPE<strong>Application</strong>Rate(g a.i./m 2 )AreaTreated(ha)Dermalabsorbed dose(mg/day) aInhalationabsorbed dose(mg/day) aTotal operatorsystemic exposure(mg/kg b.w./day) aRiskQuotient(RQ) bMixing/loading: Half-face respirator + chem. resistant full-body + 0.1 1 0.1976boots + gloves c<strong>Application</strong>: Half-face respirator + chem. resistant full-body +boots + gloves c 0.48130.01320.0174) 0.0101)7Mixing/loading: Air-hose RPE + chem. resistant full-body +0.1 1 0.1976boots + gloves c<strong>Application</strong>: Air-hose RPE + chem. resistant full-body + boots +gloves c 0.4813abAssumes 30% dermal absorption <strong>for</strong> concentrate and <strong>for</strong> diluted spray; 100% inhalation absorption; 70kg body weight at application;nilnil) 0.0097RQ = Total Estimated Occupational Exposure (dermal mixing/loading & application, plus inhalation at mixing/loading & application per kg body weight) / AOEL whereAOEL = 0.0014 mg/kg b.w./day; RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;)7cP <strong>for</strong> PPE (% penetration): none, 1 (100%); overalls, 0.2 (20%); chemical resistant full-body suit, 0.05 (5%); gloves, 0.1 (10%);P <strong>for</strong> RPE (% penetration): none, 1 (100%); half-face respirator, 0.1 (10%); full-face, 0.02 (2%); air-hose/SCBA, nil exposure (0%) (Thongsinthusak et al., 1993 inAPVMA, 2008b).Dichlorvos reassessment – application Page 305 <strong>of</strong> 436
Conclusions on operator exposure estimates and risk assessment4.35 Scenarios 1-16 give unacceptable risks <strong>for</strong> operators (mixer/loader/applicators),even with PPE, RPE and engineering controls, where appropriate, except <strong>for</strong>Scenarios (9 & 10) (automated fogging operations with RTU gas in glasshouses insome cases) and Scenarios (13 & 14) (automated fogging with EC solutions inCymbidium production, with restrictions). No outdoor uses <strong>of</strong> dichlorvos instrawberries, vegetables, cereal berries, fruit trees or passion fruit gave acceptableoperator risk estimates (Scenarios 1-8).4.36 Vegetables/Mushrooms: RTU dichlorvos gas through automatic spray systems at50 mg/m 3 may be used <strong>for</strong> <strong>the</strong> fogging <strong>of</strong> glasshouse crops/ mushrooms(Scenarios 9 & 10), provided: work day exposure is limited to <strong>the</strong> use <strong>of</strong> only onedichlorvos gas cylinder, and half-face respirator, chemical-resistant gloves,overalls, eye protection and boots are worn. Two dichlorvos gas cylinders, as amaximum, can be handled in a day (see Table VI) provided: a full-face respirator,chemical-resistant gloves, overalls, eye protection and boots are worn duringcylinder changeover. The cylinder change over restriction means that only small(approximately 0.25 ha) spaces can be treated with 7 L cylinders, but treatment <strong>of</strong>larger spaces (up to 1.25 ha) is possible using 35L cylinders using automatedsystems.4.37 Cymbidium: EC dichlorvos solutions through automatic spray systems at 1.3kga.i./ha may be used <strong>for</strong> fogging glasshouses during Cymbidium production(Scenarios 13 & 14), provided: work day exposure is limited to 0.1ha (1,000m 2 ),and a respirator <strong>of</strong> at least A1P2 specification, eye protection and chemicalresistant gloves are worn during mixing/loading. Automated treatment or manualfine spray application at 1.8 kg a.i./ha in glasshouses <strong>for</strong> Cymbidium productiondo not give acceptable risk estimates.4.38 As can be seen from Tables VI-VIII above, some <strong>of</strong> <strong>the</strong> enclosed spaceapplications give acceptable risks <strong>for</strong> operators if adequate PPE and RPE areworn. In some cases <strong>the</strong> length <strong>of</strong> work exposure (area/volume treated) also needsto be limited.4.39 RTU dichlorvos gas through automatic spray systems at 50 mg/m 3 may be used<strong>for</strong> <strong>the</strong> fogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 375 or 3750 m 3 (Scenarios 17 &18; Table VI), provided: work day exposure is limited to <strong>the</strong> use <strong>of</strong> only onedichlorvos gas cylinder, and half-face respirator, chemical-resistant gloves,overalls, eye protection and boots are worn during cylinder changeover. RTUdichlorvos gas through automatic spray systems at 50 mg/m 3 may be used <strong>for</strong> <strong>the</strong>fogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 12500 m 3 (Scenarios 17 & 18), provided:work day exposure is limited to <strong>the</strong> use <strong>of</strong> only two dichlorvos gas cylinders, andfull-face respirator, chemical-resistant gloves, overalls, eye protection and bootsare worn during cylinder changeover. Thus Scenarios 17 and 18 give acceptablerisk estimates <strong>for</strong> all treatment volumes, provided sufficient PPE/RPE is worn.4.40 <strong>Application</strong> <strong>of</strong> RTU dichlorvos gas at 50 mg/m 3 may be used <strong>for</strong> <strong>the</strong> manualfogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 375 m 3 (Scenarios 19; Table VI),Dichlorvos reassessment – application Page 306 <strong>of</strong> 436
provided: work day exposure is limited to 1.5 minutes exposure, <strong>the</strong> use <strong>of</strong> onlyone dichlorvos gas cylinder, and half-face respirator and chemical-resistant glovesare worn during cylinder changeover.4.41 <strong>Application</strong> <strong>of</strong> RTU dichlorvos gas at 50 mg/m 3 may be used <strong>for</strong> <strong>the</strong> manualfogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 3750 m 3 (Scenarios 19; Table VI),provided: work day exposure is limited to 15 minutes exposure, <strong>the</strong> use <strong>of</strong> onlyone dichlorvos gas cylinder, a half-face respirator and chemical-resistant glovesare worn during cylinder changeover, and air-hose respirator or SCBA, chemicalresistantgloves, chemical-resistant full-body suit, eye protection and boots areworn during application. Thus <strong>for</strong> Scenario 19, manual treatment <strong>of</strong> largervolumes (≥3750 m 3 ) does not give acceptable estimates even with air hose RPEduring application. The risk estimate is primarily driven by <strong>the</strong> APVMA cylinderchange exposure estimates which mean that <strong>the</strong> use <strong>of</strong> two cylinders per day isunacceptable even with PPE/RPE during changeover.4.42 Mixing/loading fogging solutions at 0.05g a.i./m 3 <strong>for</strong> application throughautomatic spray systems into enclosed industrial spaces <strong>of</strong> 375 m 3 (Scenarios 20& 21; Table VII) may be done, provided: work day exposure is limited to <strong>the</strong>specified volume, and a respirator <strong>of</strong> at least A1P2 specification, chemicalresistantgloves, overalls, eye protection and boots are worn duringmixing/loading. Mixing/loading fogging solutions at 0.15g a.i./m 3 <strong>for</strong> applicationthrough automatic spray systems into enclosed industrial spaces <strong>of</strong> 375 m 3(Scenarios 20 & 21) may be done, provided: work day exposure is limited to <strong>the</strong>specified volume, and a respirator <strong>of</strong> at least A1P2 specification, chemicalresistantgloves, overalls, eye protection and boots are worn duringmixing/loading. Thus <strong>for</strong> Scenarios 20 & 21, only <strong>the</strong> smallest treatment volumesgive acceptable risk estimates due to <strong>the</strong> exposure during mixing/loading, but notlarger volumes (≥3750 m 3 ).4.43 Manual application <strong>of</strong> fogging solutions at 0.05 or 0.15g a.i./m 3 into enclosedindustrial spaces <strong>of</strong> 375 m 3 (Scenarios 22 & 23; Table VII), may be doneprovided: work day exposure is limited <strong>the</strong> specified volume, and half-facerespirator (at least A1P2 specification), chemical-resistant gloves, overalls, eyeprotection and boots are worn during mixing/loading and application. Thus <strong>for</strong>Scenarios 22 & 23, only <strong>the</strong> smallest treatment volumes give acceptable riskestimates primarily due to <strong>the</strong> exposure during mixing/loading.4.44 The surface spraying <strong>of</strong> <strong>the</strong> smallest space 150 m 2 at 0.1g a.i./m 2 using highpressure handwand (Scenarios 24 & 25; Table VIII), may be done provided: workday exposure is limited <strong>the</strong> specified area, and a half-face respirator, chemicalresistantgloves, chemical-resistant full-body suit, eye protection and boots areworn during mixing/loading and application.4.45 The surface spraying <strong>of</strong> <strong>the</strong> smallest space 150 m 2 at 0.30g a.i./m 2 using highpressure handwand (Scenarios 24 & 25; Table VIII), may be done provided: workday exposure is limited <strong>the</strong> specified area, and air-hose respirator or SCBA,chemical-resistant gloves, chemical-resistant full-body suit, eye protection andboots are worn during mixing/loading and application. Thus <strong>for</strong> Scenarios 24 &Dichlorvos reassessment – application Page 307 <strong>of</strong> 436
25, surface spraying <strong>of</strong> larger spaces (1500 or 2500 m 2 ) at ei<strong>the</strong>r application rategive unacceptable risk estimates primarily due to <strong>the</strong> exposure duringmixing/loading.4.46 Both <strong>the</strong> domestic uses are assumed to be carried out by amateurs without <strong>the</strong> use<strong>of</strong> PPE or RPE. Surface/crevice RTU (aerosol can) applications indoors over7.44m 2 (Scenarios 26 & 27; Table IX) and treatment <strong>of</strong> larger outdoor spaces withRTU spray-mixes using a knapsack sprayer (Scenarios 28 & 29; Table IX) arepredicted to give unacceptable risks.4.47 The public space application (Scenario 30; Table X) (<strong>for</strong> pr<strong>of</strong>essional applicators)gives an unacceptable risk even <strong>for</strong> <strong>the</strong> treatment <strong>of</strong> only 1 hectare when wearinga chemical resistant full-body suit and air-hose RPE or SCBA.Dichlorvos reassessment – application Page 308 <strong>of</strong> 436
5POST-APPLICATION OR RE-ENTRY WORKER EXPOSURES & RISK ASSESSMENT5.1 Only a limited number <strong>of</strong> <strong>the</strong> proposed use scenarios <strong>for</strong> dichlorvos gaveacceptable risks, based on modelled estimates <strong>of</strong> exposure to operators.5.2 The routes <strong>of</strong> exposure during post-application activities are analogous to those<strong>for</strong> <strong>the</strong> operator, i.e. dermal and inhalation. However, <strong>the</strong> sources are different:foliage, soil and dust may contribute as treated surfaces cause pesticide residues tobe transferred to <strong>the</strong> skin.5.4 Most maintenance activities include frequent contact with <strong>the</strong> foliage <strong>of</strong> <strong>the</strong> crop.There<strong>for</strong>e, dermal exposure is considered to be <strong>the</strong> most important exposure routeduring <strong>the</strong>se re-entry activities. The amount <strong>of</strong> resulting exposure (<strong>for</strong> a certainactivity) depends on <strong>the</strong> amount <strong>of</strong> residue on foliage, <strong>the</strong> intensity <strong>of</strong> contact with<strong>the</strong> foliage and <strong>the</strong> duration <strong>of</strong> contact.5.5 The length <strong>of</strong> time between possible applications (7 days) was long enough, given<strong>the</strong> dissipation rates <strong>for</strong> dichlorvos (see below), to treat <strong>the</strong> applications separatelyand not cumulatively, i.e. complete dissipation is assumed between applications 7days apart.5.6 Studies indicate that delays between application and handling can significantlyreduce <strong>the</strong> extent <strong>of</strong> dermal exposure as only about 5% <strong>of</strong> applied dichlorvosremains on <strong>the</strong> leaf surfaces after 20 minutes, while about 50% was volatilisedand 45% absorbed by <strong>the</strong> plant (Casida et al., 1962 in WHO/IPCS, 1971).5.7 Inhalation exposure may potentially occur from residual vapour and airborneaerosols. Movement <strong>of</strong> <strong>the</strong> crop may also result in inhalation exposure toaerosol/vapour as well as dust during re-entry activities.Re-entry into treated outdoor cropsDermal Exposures:Dislodgeable foliar residue (DFR)5.8 The amount <strong>of</strong> residue on foliage depends on several factors, <strong>for</strong> example, <strong>the</strong>application rate, targeting and retention <strong>of</strong> spray, crop type and <strong>the</strong> amount <strong>of</strong>foliage (leaf area index). Moreover, dissipation <strong>of</strong> residues on crop foliage overtime depends on <strong>the</strong> physical and chemical properties <strong>of</strong> <strong>the</strong> applied activesubstance as well as on environmental conditions. Where experimentallydetermined dislodgeable foliar residue data are not available, a worse caseassessment <strong>of</strong> <strong>the</strong> initial DFR (DFR0), in a first tier assessment, assumes 3micrograms <strong>of</strong> active substance/square centimetre <strong>of</strong> foliage/per kg a.s.applied/hectare (UK CRD, 2008a).5.9 However, some experimental data on dichlorvos is available. Only 5% <strong>of</strong> a 0.1%aqueous 32 P-dichlorvos solution remained on <strong>the</strong> leaf surfaces <strong>of</strong> maize, cottonDichlorvos reassessment – application Page 309 <strong>of</strong> 436
and peas 20 minutes after application (Casida et al., 1962; Original not sighted;APVMA, 2008b).5.10 Using <strong>the</strong> Casida et al. (1962) data a general DFR t (μg/cm 2 /kg a.i./ha) value canbe derived <strong>for</strong> dichlorvos using <strong>the</strong> equation (US EPA, 1997):DFR t = (AR x F) x (1-D) t x CF2 x CF3where:AR = application rate (kg/ha);F = fraction <strong>of</strong> a.i. retained on foliage (unitless);D = fraction <strong>of</strong> residue that dissipates daily (unitless);t = post-application day on which exposure is being assessed;CF2 = conversion factor to convert <strong>the</strong> kg a.i. in <strong>the</strong> application rate to μg<strong>for</strong> <strong>the</strong> DFR value (1 x 10 9 μg/kg);CF3 = conversion factor to convert <strong>the</strong> surface area units (ha) in <strong>the</strong>application rate to cm 2 <strong>for</strong> <strong>the</strong> DFR value (1 x 10 -8 ha/cm 2 if <strong>the</strong> applicationrate is per hectare).Using Casida et al. data: 5% remains on surface at 20 mins, F = 0.05;D is not needed <strong>for</strong> <strong>the</strong>se scenarios as <strong>the</strong> exposure is assumed to occur on<strong>the</strong> day <strong>of</strong> application after residue has dried;DFR t = (1 x 0.05) x 1E9 x 1E-8 = (1 x 0.05) x 10= 0.5 μg/cm 2 per kg a.i./haTransfer coefficient (TC)5.11 The transfer <strong>of</strong> residues from <strong>the</strong> plant surface to <strong>the</strong> clo<strong>the</strong>s or skin <strong>of</strong> <strong>the</strong> workercan be regarded as more or less independent <strong>of</strong> <strong>the</strong> kind <strong>of</strong> product applied and <strong>the</strong>level <strong>of</strong> exposure will depend on <strong>the</strong> intensity and duration <strong>of</strong> contact with <strong>the</strong>foliage. This is also determined by <strong>the</strong> nature and duration <strong>of</strong> <strong>the</strong> activity duringre-entry. There<strong>for</strong>e, it is possible to group various crop habitats and re-entryactivities. The EUROPOEM Group recommended indicative TC values <strong>for</strong>potential dermal exposure <strong>for</strong> four different harvesting scenarios. For o<strong>the</strong>r reentryscenarios, TC data may be extrapolated where <strong>the</strong> scenarios are consideredto be comparable, i.e. <strong>the</strong> intensity and duration <strong>of</strong> contact with <strong>the</strong> foliage issimilar (UK CRD, 2008a).5.12 Three <strong>of</strong> <strong>the</strong> TC values in <strong>the</strong> European guidance documents were applicable todichlorvos use on outdoor crops: tasks in vegetable crops, 2500 cm 2 /hr; tasks infruit trees, 4500 cm 2 /hr; and, tasks in berry crops, 3000 cm 2 /hr.Predicted worker dermal exposures (D)5.13 Predicted dermal exposure <strong>for</strong> this scenario based on <strong>the</strong> UK CRD equation(modified by adding a factor <strong>for</strong> dermal absorption and dividing by <strong>the</strong> worker‘sbody weight) gives:Dichlorvos reassessment – application Page 310 <strong>of</strong> 436
D = DFR x TC x DA x WR x AR x P / BWWhere:D = Dermal Exposure [μg a.s./person*d]DFR = Dislodgeable Foliar Residue per kg a.s./haTC = Transfer Coefficient [cm²/person/h]DA = percentage dermal absorption, expressed as a fractionWR = Work RateAR = <strong>Application</strong> RateP = Penetration Factor <strong>for</strong> Clothing [= 1] which assumes one layer <strong>of</strong> ordinaryclothing is taken into accountBW = bodyweight (70 kg)5.14 In line with operator exposure estimates, 30% dermal absorption is used (SeeAppendix 5).With PPE:5.15 The BBA Model <strong>for</strong> re-entry tasks assumes a Penetration Factor (P) <strong>for</strong> PPE <strong>of</strong>0.05 (i.e. 95% protection; hood/visor + overalls over long-sleeved shirt and longleggedtrousers + boots + gloves), and this value has been used with <strong>the</strong> UK CRDbased equations.Inhalation Exposures:5.16 Predicted exposure <strong>for</strong> this scenario based on <strong>the</strong> UK CRD equation firstlydetermines <strong>the</strong> quantity <strong>of</strong> substance inhaled, <strong>the</strong>n <strong>the</strong> result is modified to takeaccount <strong>of</strong> <strong>the</strong> work rate and <strong>the</strong> worker‘s body weight, in a second equation asfollows:mg a.s./hr inhaled = kg/a.s./ha applied x Task Specific FactorInhalation Exposure (I) = mg a.s./hr inhaled x WR / BWWhere:WR = Work Rate (8 hours/day)AR = <strong>Application</strong> Rate (kg/a.s./ha)BW = bodyweight (70 kg)5.17 The UK CRD model was designed <strong>for</strong> non volatile pesticides, where levels <strong>of</strong>inhalation exposure (vapour and dust) would be expected to be low in comparisonwith dermal exposure (UK CRD, 2008a). Dichlorvos is volatile, so even withmodifications based on available data significant uncertainties will remain <strong>for</strong> <strong>the</strong>estimated inhalation exposures.Dichlorvos reassessment – application Page 311 <strong>of</strong> 436
5.18 The Task Specific Factors (TSF), suggested in <strong>the</strong> UK CRD model, are not thatappropriate <strong>for</strong> out-door activities as <strong>the</strong>y were designed <strong>for</strong> <strong>the</strong> first tier <strong>of</strong> anexposure assessment relating to harvesting ornamentals and to <strong>the</strong> re-entry <strong>of</strong>greenhouses approximately 8-16 hours after treatment, but no better model isavailable. The indicative TSFs were 0.1 <strong>for</strong> cutting ornamentals; 0.01 <strong>for</strong> sorting& bundling ornamentals; 0.03 <strong>for</strong> re-entering greenhouses after low-volume-mistapplication; and, 0.15 <strong>for</strong> re-entering greenhouses after ro<strong>of</strong> fogger application.As <strong>the</strong> tasks in <strong>the</strong>se Scenarios are outside tending Berries/Fruit andVegetables/Cereals <strong>the</strong> lowest TSF 0.01 is proposed (assuming that inhalationexposure would be similar, or less, than that while bundling ornamentals indoors).5.19 Using <strong>the</strong> data from Casida et al. (1962), 20 minutes after application to <strong>the</strong> leafsurfaces <strong>of</strong> maize, cotton and peas about 50% was volatilised, while 5% remainson <strong>the</strong> leaf surfaces and 45% absorbed by <strong>the</strong> plant (in APVMA, 2008b). It isassumed <strong>the</strong>re<strong>for</strong>e that only 50% <strong>of</strong> <strong>the</strong> application rate is available <strong>for</strong> possibleinhalation (See Appendix 5).Dichlorvos reassessment – application Page 312 <strong>of</strong> 436
Re-entry into out-door crops (Scenarios 1- 8)Scenario:Table XII: Re-Entry Worker Exposure Estimates & Risk Assessment – Scenarios 1 - 8: Out-door Crops<strong>Application</strong> Rate(AR)[kg a.s./ha]Modified Model with or without PPE aTransferCoefficient(TC)[cm²/person/h]Dermal/InhalationExposureswithout PPE/RPE[μg a.s./kg b.w./d]1 & 2 Berries e reaching, picking 0.8 3000 D = 41 b3a & 4a Vegetablesereaching, picking 0.8 2500 D = 34 bRisk Quotient(RQ) withoutPPE/RPE dDermal/InhalationExposures withPPE/RPE[μg a.s./kg b.w./d]I = 0.46 c 30 2.06I = 0.463b & 4b Cereals e Scouting 0.8 1500 D = 21 bI = 0.463c & 4c Berries e reaching, picking 0.8 3000 D = 41 b5 & 6 Fruit e searching,reaching, picking7 & 8 Fruit e searching,reaching, pickingFootnotes below2.052 4500 D = 158 b1.026 4500 D = 79 b0.009225 1.710.0092Risk Quotient withPPE/RPEd1.51.215 1.030.046 f 0.8I = 0.46 c 30 2.06nil g 1.5I = 1.17 c 114 7.90.023I = 1.17 c 57 3.960.02363Dichlorvos reassessment – application Page 313 <strong>of</strong> 436
abcdefgUK CRD Guidance <strong>for</strong> Post-<strong>Application</strong> (Re-Entry Worker) Exposure Assessment (UK CRD, 2008a), with cereals TC from US EPA (US EPA, 2000);D (dermal exposure) = DFR x TC x DA x WR x AR x P / BWWhere: DFR = 0.5 μg a.s./cm² per kg a.s./ha (Casida et al., 1962 in APVMA, 2008b);DA = percentage dermal absorption (30%); BW = bodyweight (70 kg); WR = 8 hours/dayP = Penetration Factor <strong>for</strong> Clothing [= 1 which assumes one layer <strong>of</strong> ordinary clothing is taken into account; or 0.05 <strong>for</strong> PPE: hood/visor + overalls over long-sleevedshirt and long-legged trousers + boots + gloves]I (inhalation exposure) = mg a.s./hr inhaled x WR / BWWhere: mg a.s./hr inhaled = kg/a.s./ha applied x Task Specific Factor; 50% volatilisation assumed (Casida et al., 1962 in APVMA, 2008b);Task Specific Factor: Berries/Fruit, Vegetables/Cereals, 0.01;P <strong>for</strong> RPE (% penetration): none, 1 (100%); half-face respirator, 0.1 (10%); full-face, 0.02 (2%); air-hose/SCBA, nil exposure (0%) – RPE is full-face respirator unlesso<strong>the</strong>rwise stated (Thongsinthusak et al., 1993 in APVMA, 2008b);RQ = Total Estimated Occupational Exposure / AOEL where AOEL = 1.4 μg/kg b.w./day RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed;Assumes 1 or 2 treatments per year (7 days between applications), with complete dissipation between repeat applications;Half-face respirator;Air-hose/SCBA (Scenarios 1 & 2 RQs would also be unacceptable with Air-hose/SCBA).Dichlorvos reassessment – application Page 314 <strong>of</strong> 436
Re-entry into treated glasshouses during crop production (Scenarios 9-12)5.22 Dichlorvos residues on surface and in <strong>the</strong> air after indoor application areinfluenced by environmental parameters, such as <strong>the</strong> rate <strong>of</strong> air exchange,temperature and <strong>the</strong> amount <strong>of</strong> sunlight penetration. Deposited dichlorvos may bedegraded, adsorbed or re-enter <strong>the</strong> atmosphere (Brouwer et al., 1992 in APVMA,2008b). Rapid degradation can occur on concrete or glass, whereas wood may actas a reservoir (Hussey & Hughes, 1963 in APVMA, 2008b).5.23 The APVMA reported results from two studies carried out in a glasshouse mistedat 33 mg dichlorvos/m 3 , where <strong>the</strong> dissipation kinetics in <strong>the</strong> 2 experimentsshowed considerable variation, especially after <strong>the</strong> first 240 minutes postapplication(Brouwer et al., 1992 in APVMA, 2008b).5.24 In <strong>the</strong> first study <strong>the</strong> glasshouse was unventilated and <strong>the</strong>re was a narrowtemperature range (11.6 – 14ºC), and gave <strong>the</strong> slowest dissipation. Airbornedichlorvos levels declined progressively from 8860 to 715 μg/m 3 over 6 hours.When regression analysis <strong>of</strong> Log 10 concentration vs time was per<strong>for</strong>med, <strong>the</strong> Yintercept was 3.84 (or log [6900] μg/m 3 ) and <strong>the</strong> slope [<strong>the</strong> rate <strong>of</strong> loss <strong>of</strong>dichlorvos] was -0.0031/min.5.25 In <strong>the</strong> second study <strong>the</strong> glasshouse was ventilated after 360 minutes. Airbornedichlorvos levels fell from 9910 to 875 μg/m 3 over 240 minutes. When regressionanalysis <strong>of</strong> Log 10 concentration vs time was per<strong>for</strong>med, <strong>the</strong> Y intercept was 3.84(or log [6900] μg/m 3 ) and <strong>the</strong> slope was -0.0043/min. After 240 minutes <strong>the</strong>temperature increased from 12 to 24ºC, and <strong>the</strong> dichlorvos concentrationincreased to 1000 μg/m 3 . The slope <strong>of</strong> <strong>the</strong> post-ventilation Log 10 concentration vstime plot was -0.018/min, faster than ei<strong>the</strong>r <strong>of</strong> <strong>the</strong> pre-ventilation rate losses.REI <strong>for</strong> workers ventilating <strong>the</strong> glasshouse after treatment:5.26 As <strong>the</strong> New Zealand use rate in glasshouses is 50 mg dichlorvos/m 3 <strong>for</strong> crops (notflowers) <strong>the</strong> application rate will be approximately 1.5 times <strong>the</strong> rate used in <strong>the</strong>Brouwer et al. study. The regression plot intercept is adjusted upwards to 4.02(Log 10 [6900 x 1.515]) while <strong>the</strong> same slope (-0.0031/min) has been assumed.This is <strong>the</strong> approach and slope used by APVMA in <strong>the</strong>ir assessment <strong>for</strong>ventilating <strong>the</strong> greenhouse (2008b).5.27 Taking <strong>the</strong> slowest initial decline in dichlorvos levels from <strong>the</strong> two studies, <strong>the</strong>airborne concentration <strong>of</strong> dichlorvos at 240 minutes will be:10 (4.02 + [-0.0031 x 240]) = 1888 μg/m 35.28 Re-entering <strong>the</strong> treated glasshouse to ventilate it would expose <strong>the</strong> worker byinhalation at approximately 1.89 mg/m 3 . If <strong>the</strong> duration <strong>of</strong> exposure was 30minutes, <strong>the</strong> worst-case upper limit, <strong>the</strong> inhalation exposures with various RPEwould be <strong>the</strong> values set out in Table XIII:Dichlorvos reassessment – application Page 315 <strong>of</strong> 436
Table XIII: Re-entry into glasshouses treated at 50 mg dichlorvos/m 3 – inhalation exposure atventing (240 minutes after application)Airbornedichlorvosconc.(mg/m 3 )Duration (h)Exposure(mg) aDose (mg/kg b.w.) bRespiratory protection cNone Half-face Full-face Air-hose1.89 0.5 0.95 0.0136 0.0014 0.0003 NilabcInhalation rate, 1 m 3 /hour;Body weight, 70kg;Protection factors from APVMA, 2008b: factor <strong>of</strong> 0.1 <strong>for</strong> a half face mask and a factor <strong>of</strong> 0.02 <strong>for</strong> afull face mask respectively, and no exposure <strong>for</strong> air-hose (supplied air system) [results rounded].5.29 Predicted dermal exposure <strong>for</strong> this scenario when using PPE (hood/visor +overalls over long-sleeved shirt and long-legged trousers + boots + gloves) basedon <strong>the</strong> UK CRD equation (by adding a factor <strong>for</strong> dermal exposure and dividing by<strong>the</strong> worker‘s body weight) gives:D = DFR x TC x DA x WR x AR x P / BWD = 0.5 x 2500 x 0.3 x 0.5 x 1.25 x 0.05 / 70 =11.7188 / 70 = 0.1674 μg a.s./kg b.w./dayChanging <strong>the</strong> units and rounding <strong>the</strong> dermal exposure with PPE is 0.0002mga.s./kg bw/day.Where:D = Dermal Exposure [μg a.s./person*d]DFR = Dislodgeable Foliar Residue per kg a.s./ha = 0.5 μg a.s./cm² per kg a.s./ha[Note: a DFR based on <strong>the</strong> Casida et al. (1962) data is used, showing only 5% <strong>of</strong>applied active available <strong>for</strong> skin contamination 20 minutes after application; seeSections 5.9 & 5.10]:TC = Transfer Coefficient [cm²/person/h] [<strong>the</strong> lowest TC was Vegetables – 2500(UK CRD); ventilating <strong>the</strong> building should result in less transfer]DA = percentage dermal absorption [30%], expressed as a fraction.WR = Work Rate [0.5 hours/day]AR = <strong>Application</strong> Rate [1.25 kg a.s./ha; assumes 2.5m building height]P = Penetration Factor <strong>for</strong> Clothing [= 0.05] German BBA Model <strong>for</strong> re-entrytasks that assumes a Penetration Factor (P) <strong>for</strong> PPE <strong>of</strong> 0.05 (i.e. 95% protection)hood/visor + overalls over long-sleeved shirt and long-legged trousers + boots +glovesBW = bodyweight [70 kg]5.30 Predicted total exposures and risk assessments indicate that re-entry to treatedglass-houses <strong>for</strong> <strong>the</strong> purpose <strong>of</strong> venting (taking 30 minutes or less) may beDichlorvos reassessment – application Page 316 <strong>of</strong> 436
acceptable 240 minutes after application if PPE (hood/visor + overalls over longsleevedshirt and long-legged trousers + boots + gloves) and RPE (full-face or airhose)are used. See Table XIV:Table XIV: Re-entry into glasshouses treated at 50 mg dichlorvos/m 3 – total exposure and risksat venting: 30 minutes exposure (4 hours after application)Dose (mg/kg b.w.) aRespiratory protection bNone Half-face Full-face Air-hoseInhalation 0.0136 0.0014 0.0003 NilDermal (with PPE as above) 0.0002 0.0002 0.0002 0.0002Total 0.0138 0.0016 0.0005 0.0002Risk Quotient (RQ) c 9.9 d 1.1 d 0.4 0.1abBody weight, 70kg;Protection factors from APVMA, 2008b: factor <strong>of</strong> 0.1 <strong>for</strong> a half face mask and a factor <strong>of</strong> 0.2 <strong>for</strong> afull face mask respectively, and no exposure <strong>for</strong> air-hose (supplied air system) [results rounded];cRQ = Total Estimated Occupational Exposure / AOEL where AOEL = 0.0014 mg/kg b.w./day;dRQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed.REI <strong>for</strong> workers re-entering and working in a glasshouse <strong>for</strong> vegetable production:5.31 The second Brouwer et al. study where <strong>the</strong> glasshouse was ventilated after 360minutes (see 5.25) indicated a faster rate <strong>of</strong> dissipation <strong>of</strong> air concentrations onceventilation had started. No fur<strong>the</strong>r data are available on <strong>the</strong> reduction in DFR,o<strong>the</strong>r than <strong>the</strong> in<strong>for</strong>mation <strong>of</strong> Casida et al. (1962), so it is assumed that beyond 20minutes after treatment, no fur<strong>the</strong>r dissipation from plant surfaces occurs. Bycalculating a systemic dose from dermal exposure, <strong>the</strong> residual portion <strong>of</strong> <strong>the</strong>AOEL may be used to derive a REI when <strong>the</strong> workplace atmosphericconcentration <strong>of</strong> dichlorvos has dropped low enough to allow an 8-hour work-day.5.32 The UK CRD equation <strong>for</strong> dermal exposure with TC <strong>for</strong> Berries (3000) and PPE,(hood/visor + overalls over long-sleeved shirt and long-legged trousers + boots +gloves) indicates:D = DFR x TC x % absorbed x WR x AR x P / BWD = 0.5 x 3000 x 0.3 x 8 x 1.25 x 0.05 / 70 =225 / 70 = 3.214 μg a.s./kg b.w./day5.33 In this instance <strong>the</strong> estimated dermal exposure is 3.214 μg a.s./kg b.w./day(0.0032 mg/kg bw/day) which exceeds <strong>the</strong> AOEL (1.4 μg/kg b.w./day) with a RQ= 2.3, be<strong>for</strong>e any contribution from inhalation has been considered.Dichlorvos reassessment – application Page 317 <strong>of</strong> 436
5.34 No REI <strong>for</strong> treated glasshouses and similar crop production facilities can be set<strong>for</strong> an 8-hour working day, based on <strong>the</strong> available in<strong>for</strong>mation.5.35 If working access to <strong>the</strong> treated building is limited to only 2 hours per day, <strong>the</strong>nestimated dermal exposure with PPE reduces to 0.804 μg a.s./kg b.w./day, andinhalation exposure can be estimated.5.36 The remaining AOEL, assuming re-entry workers have not been exposed todichlorvos during o<strong>the</strong>r tasks, (1.4 - 0.804 = 0.596 μg a.s./kg b.w./day) may beassigned to inhalation exposures at a respiration rate <strong>of</strong> 1 m 3 /hour (APVMA,2008b). To convert <strong>the</strong> exposure limit by body weight to an atmospheric level:Inhalation exposure limit (μg a.s./kg b.w./day) x Body wt (kg)Respiration volume (contaminated) (m 3 /hour) x Working day (hours)(0.596 x 70) / (1 x 2) = 21 μg/m 3[Note: Working day is reduced to 2 hours from <strong>the</strong> default 8.]5.37 In <strong>the</strong> second Brouwer et al. study where <strong>the</strong> glasshouse was ventilated, <strong>the</strong> slope<strong>of</strong> <strong>the</strong> post-ventilation Log 10 concentration vs time plot was -0.018/min. Thisregression line may be used to estimate a REI <strong>for</strong> glasshouses treated at 50 mg/m 3 ,from:-{((Log 10 (Initial concentration) – Log 10 (Final concentration)) ÷ slope.}5.38 If <strong>the</strong> dichlorvos concentration at <strong>the</strong> start <strong>of</strong> ventilation is 1888 μg/m 3 and <strong>the</strong>slope is -0.018/min, <strong>the</strong>n <strong>the</strong> time taken <strong>for</strong> <strong>the</strong> concentration to decline to 21μg/m 3 will be (3.276 – 1.322) ÷ 0.018 = 109 minutes or 1.8 hours. This assumesno RPE is used, but PPE is used.5.39 If re-entry activities could be limited to 2 hours with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles+ overalls over long-sleeved shirt and long-legged trousers + boots + gloves), aREI <strong>for</strong> treated glasshouses and similar plant production facilities could be set at 4hours after <strong>the</strong> onset <strong>of</strong> ventilation, allowing <strong>for</strong> environmental variation betweendifferent structures. Hat and goggles are specified instead <strong>of</strong> <strong>the</strong> hood and visorused in <strong>the</strong> exposure modelling, as <strong>the</strong>y would seem to be more practical while<strong>of</strong>fering adequate protection.[Note: The P005877 Armour-Crop label gives a WithHolding Period (WHP) <strong>of</strong>three days <strong>for</strong> green-house capsicum; P001132 Nuvos label gives a WHP <strong>of</strong> 3days <strong>for</strong> ―o<strong>the</strong>r fruit and vegetables‖.]Dichlorvos reassessment – application Page 318 <strong>of</strong> 436
Re-entry into treated glasshouses used <strong>for</strong> Cymbidium production (Scenarios 13-16)REI <strong>for</strong> workers ventilating <strong>the</strong> glasshouse after treatment <strong>for</strong> Cymbidium production:5.40 The New Zealand use rates in glasshouses <strong>for</strong> flower production are 52 and 72 mgdichlorvos/m 3 [The use rates are quoted as 1300g a.i./ha <strong>for</strong> a maximum <strong>of</strong> 0.1haor 2500m 3 i.e. 1300 / 25000 = 52 mg/m 3 , assuming a 2.5m building height; and1800g a.i./ha <strong>for</strong> a maximum <strong>of</strong> 0.2ha or 5000m 3 i.e. 1800 / 25000 = 72 mg/m 3 ].These application rates are approximately 1.58 and 2.18 times <strong>the</strong> rate (33 mg/m 3 )used in <strong>the</strong> Brouwer et al. study without ventilation. The regression plotintercepts are adjusted upwards to 4.04 (Log 10 [6900 x 1.58]) and 4.18 (Log 10[6900 x 2.18]) while <strong>the</strong> same slope (-0.0031/min) has been assumed.5.41 Taking <strong>the</strong> slowest initial decline in dichlorvos levels, <strong>the</strong> airborne concentration<strong>of</strong> dichlorvos at 240 minutes will be:At 52 mg dichlorvos/m 3 : 10 (4.04 + [-0.0031 x 240]) = 1977 μg/m 3At 72 mg dichlorvos/m 3 : 10 (4.18 + [-0.0031 x 240]) = 2729 μg/m 35.42 Re-entering <strong>the</strong> treated glasshouse to ventilate it would expose <strong>the</strong> worker byinhalation at approximately 1.98 or 2.73 mg/m 3 . If <strong>the</strong> duration <strong>of</strong> exposure was30 minutes, <strong>the</strong> worst-case upper limit, <strong>the</strong> inhalation exposures with various RPEwould be, Table XV:Table XV: Re-entry into glasshouses treated at 52 or 72 mg dichlorvos/m 3 – inhalation exposureat venting (240 minutes after application)Airbornedichlorvosconc.(mg/m 3 )Duration (h)Exposure(mg) aDose (mg/kg b.w.) bRespiratory protection cNone Half-face Full-face Air-hose1.98 0.5 0.99 0.014 0.001 0.0003 Nil2.73 0.5 1.37 0.020 0.002 0.0004 NilabcInhalation rate, 1 m 3 /hour;Body weight, 70kg;Protection factors from APVMA, 2008b: factor <strong>of</strong> 0.1 <strong>for</strong> a half face mask and a factor <strong>of</strong> 0.2 <strong>for</strong> afull face mask respectively, and no exposure <strong>for</strong> air-hose (supplied air system) [results rounded].5.43 Predicted dermal exposure <strong>for</strong> <strong>the</strong>se scenarios when using PPE (hood/visor +overalls over long-sleeved shirt and long-legged trousers + boots + gloves) basedon <strong>the</strong> UK CRD equation (by adding a factor <strong>for</strong> dermal exposure and dividing by<strong>the</strong> worker‘s body weight) gives:At 52 mg dichlorvos/m 3 (1300g a.i./ha):D = DFR x TC x DA x WR x AR x P / BWD = 0.5 x 5000 x 0.3 x 0.5 x 1.3 x 0.05 / 70 = 24.375 / 70 = 0.348 μg a.s./kg b.w./dayDichlorvos reassessment – application Page 319 <strong>of</strong> 436
At 72 mg dichlorvos/m 3 (1800g a.i./ha):D = 0.5 x 5000 x 0.3 x 0.5 x 1.8 x 0.05 / 70 = 33.75 / 70 = 0.482 μg a.s./kg b.w./dayWhere:D = Dermal Exposure [μg a.s./person*d]DFR = Dislodgeable Foliar Residue per kg a.s./ha = 0.5 μg a.s./cm² per kg a.s./ha[Note: a DFR based on <strong>the</strong> Casida et al. (1962) data is used, showing only 5% <strong>of</strong>applied active available <strong>for</strong> skin contamination 20 minutes after application; seeSections 5.9 & 5.10]TC = Transfer Coefficient [cm²/person/h] [e.g. Ornamentals - Cut / Sort / Bundle /Carry - 5000 (UK CRD)]DA = percentage dermal absorption [30%], expressed as a fractionWR = Work Rate [0.5 hours/day]AR = <strong>Application</strong> Rate [1.3 or 1.8 kg a.s./ha]P = Penetration Factor <strong>for</strong> Clothing [= 0.05] German BBA Model <strong>for</strong> re-entrytasks that assumes a Penetration Factor (P) <strong>for</strong> PPE <strong>of</strong> 0.05 (i.e. 95% protection)hood/visor + overalls over long-sleeved shirt and long-legged trousers + boots +glovesBW = bodyweight [70 kg]5.44 Predicted total exposures and risk assessments indicate that re-entry to treatedglasshouses <strong>for</strong> <strong>the</strong> purpose <strong>of</strong> venting (taking 30 minutes or less) may beacceptable 4 hours after application if PPE (hood/visor + overalls over longsleevedshirt and long-legged trousers + boots + gloves) and RPE (full-face or airhose)are used. See Tables XVI and XVII:Table XVI: Re-entry into glasshouses treated at 52 mg dichlorvos/m 3 – total exposure and risksat venting: 30 minutes exposure (240 minutes after application)Dose (mg/kg b.w.) aRespiratory protection bNone Half-face Full-face Air-hoseInhalation 0.014 0.001 0.0003 NilDermal (with PPE above) 0.0003 0.0003 0.0003 0.0003Total 0.0143 0.0013 0.0006 0.0003Risk Quotient (RQ) c 10 d 0.9 0.4 0.2abBody weight, 70kg;Protection factors from APVMA, 2008b: factor <strong>of</strong> 0.1 <strong>for</strong> a half face mask and a factor <strong>of</strong> 0.02 <strong>for</strong> afull face mask respectively, and no exposure <strong>for</strong> air-hose (supplied air system) [results rounded];cdRQ = Total Estimated Occupational Exposure / AOEL where AOEL = 0.0014 mg/kg b.w./day;RQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed.Dichlorvos reassessment – application Page 320 <strong>of</strong> 436
Table XVII: Re-entry into glasshouses treated at 72 mg dichlorvos/m 3 – total exposure and risksat venting: 30 minutes exposure (240 minutes after application)Dose (mg/kg b.w.) aRespiratory protection bNone Half-face Full-face Air-hoseInhalation 0.025 0.003 0.0005 NilDermal (with PPE) 0.0005 0.0005 0.0005 0.0005Total 0.0255 0.0035 0.0010 0.0005Risk Quotient (RQ) c 18 d 2.5 d 0.7 0.4abBody weight, 70kg;Protection factors from APVMA, 2008b: factor <strong>of</strong> 0.1 <strong>for</strong> a half face mask and a factor <strong>of</strong> 0.02 <strong>for</strong> afull face mask respectively, and no exposure <strong>for</strong> air-hose (supplied air system) [results rounded];cRQ = Total Estimated Occupational Exposure / AOEL where AOEL = 0.0014 mg/kg b.w./day;dRQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed.REI <strong>for</strong> workers re-entering and working in a glasshouse <strong>for</strong> Cymbidium production:5.45 The second Brouwer et al. study (see 5.25) where <strong>the</strong> glasshouse was ventilatedafter 360 minutes indicated a faster rate <strong>of</strong> dissipation <strong>of</strong> air concentrations onceventilation had started. No fur<strong>the</strong>r data are available on <strong>the</strong> reduction in DFR,o<strong>the</strong>r than <strong>the</strong> in<strong>for</strong>mation <strong>of</strong> Casida et al. (1962), so it is assumed that beyond 20minutes after treatment, no fur<strong>the</strong>r dissipation from plant surfaces occurs. Bycalculating a systemic dose from dermal exposure, <strong>the</strong> residual portion <strong>of</strong> <strong>the</strong>AOEL may be used to find a REI when <strong>the</strong> workplace atmospheric concentration<strong>of</strong> dichlorvos has dropped low enough to allow an 8-hour work-day.The UK CRD equation <strong>for</strong> dermal exposure with TC <strong>for</strong> Ornamentals - Cut / Sort/ Bundle / Carry - 5000 and PPE, (hood/visor + overalls over long-sleeved shirtand long-legged trousers + boots + gloves) indicates:At 52 mg dichlorvos/m 3 :D = DFR x TC x DA x WR x AR x P / BWD = 0.5 x 5000 x 0.3 x 8 x 1.3 x 0.05 / 70 = 390 / 70 = 5.57 μg a.s./kg b.w./dayAt 72 mg dichlorvos/m 3 :D = 0.5 x 5000 x 0.3 x 8 x 1.8 x 0.05 / 70 = 540 / 70 = 7.71 μg a.s./kg b.w./day[Equation parameters are as discussed in 5.43, with appropriate modifications:WR = Work Rate [8 hours/day].]Dichlorvos reassessment – application Page 321 <strong>of</strong> 436
5.46 In this instance, after treatment with 52 mg/m 3 (1300g a.i./ha) <strong>the</strong> estimateddermal exposure is 5.57 μg a.s./kg b.w./day and exceeds <strong>the</strong> AOEL (1.4 μg/kgb.w./day) with a RQ = 4, be<strong>for</strong>e any contribution from inhalation has beenconsidered.5.47 After treatment with 72 mg/m 3 (1800g a.i./ha) <strong>the</strong> estimated dermal exposure is7.71 μg a.s./kg b.w./day and exceeds <strong>the</strong> AOEL (1.4 μg/kg b.w./day) with a RQ =6, be<strong>for</strong>e any contribution from inhalation has been considered.5.48 No REI <strong>for</strong> treated glasshouses used <strong>for</strong> Cymbidium production can be set <strong>for</strong> an8-hour work day, based on <strong>the</strong> available in<strong>for</strong>mation.5.49 If working access to glasshouses and similar Cymbidium production facilitiestreated at <strong>the</strong> lowest use rate (52 mg/m 3 ; 1300g a.i./ha) is limited to only 1 hourper day, <strong>the</strong>n estimated dermal exposure with PPE reduces to 0.696 μg a.s./kgb.w./day, and inhalation exposure can be estimated.5.50 The remaining AOEL, assuming re-entry workers have not been exposed todichlorvos during o<strong>the</strong>r tasks, (1.4 - 0.696 = 0.704 μg a.s./kg b.w./day) may beassigned to inhalation exposures at a respiration rate <strong>of</strong> 1 m 3 /hour (APVMA,2008b). To convert <strong>the</strong> exposure limit by body weight to an atmospheric level:Inhalation exposure limit (μg a.s./kg b.w./day) x Body wt (kg)Respiration volume (contaminated) (m 3 /hour) x Working day (hours)At 52 mg dichlorvos/m 3 (1300g a.i./ha):(0.704 x 70) /( 1 x 1) = 49.28 μg/m 3[Note: Working day is reduced to 1 hour from <strong>the</strong> default 8.]5.51 In <strong>the</strong> second Brouwer et al. study where <strong>the</strong> glasshouse was ventilated, <strong>the</strong> slope<strong>of</strong> <strong>the</strong> post-ventilation Log 10 concentration vs time plot was -0.018/min. Thisregression line may be used to estimate a REI <strong>for</strong> glasshouses treated at 52 mg/m 3 ,from:((Log 10 (Initial concentration) – Log 10 (Final concentration)) ÷ slope.5.52 If <strong>the</strong> dichlorvos concentration at <strong>the</strong> start <strong>of</strong> ventilation is 2432 μg/m 3 aftertreatment at 52 mg/m 3 and <strong>the</strong> slope is -0.018/min, <strong>the</strong>n <strong>the</strong> time taken <strong>for</strong> <strong>the</strong>concentration to decline to 49.28 μg/m 3 will be (3.386 – 1.693) ÷ 0.018 = 94minutes or 1.6 hours. This assumes no RPE was used, but PPE was used.5.53 If re-entry activities could be limited to 1 hour with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles+ overalls over long-sleeved shirt and long-legged trousers + boots + gloves), aREI <strong>for</strong> glasshouses and similar Cymbidium production facilities treated at <strong>the</strong>Dichlorvos reassessment – application Page 322 <strong>of</strong> 436
lowest use rate (52 mg/m 3 ; 1300g a.i./ha) could be set at 4 hours after <strong>the</strong> onset <strong>of</strong>ventilation, allowing <strong>for</strong> environmental variation between different structures.Dichlorvos reassessment – application Page 323 <strong>of</strong> 436
Re-entry into treated mushroom houses (Scenarios 9-12)5.54 The Brouwer et al. (1992) data <strong>for</strong> a sunlit glasshouse <strong>of</strong> metal, glass and concretemay not be relevant <strong>for</strong> a dark mushroom house built with wood. The APVMAreported results from studies carried out in a closed and unventilated mushroomhouse sprayed at 212 mg/m 3 (Hussey & Hughes, 1963 in APVMA, 2008b). Thehalf-life <strong>of</strong> airborne dichlorvos over <strong>the</strong> first 2.5 hours was about 20 minutes,while <strong>the</strong> dissipation rate slowed over <strong>the</strong> period 6.5-17 hours with a half-life <strong>of</strong>about 7 hours (APVMA, 2008b). When regression analysis <strong>of</strong> Log 10concentration vs time was per<strong>for</strong>med on <strong>the</strong> second slower phase, <strong>the</strong> Y intercept(at t=0) was 1.358 mg/m 3 and <strong>the</strong> slope was -0.0558/hour.5.55 Acknowledging that <strong>the</strong> approach was based on little in<strong>for</strong>mation, <strong>the</strong> APVMAbased <strong>the</strong>ir estimates <strong>of</strong> re-entry exposures on unventilated mushroom houses.Their in<strong>for</strong>mation was that most <strong>of</strong> <strong>the</strong> <strong>of</strong>f-label use was carried out on spawningrooms after being filled and sealed. The spawning rooms would <strong>the</strong>n remained<strong>under</strong> controlled atmosphere <strong>for</strong> 10 days undisturbed (APVMA, 2008b).5.56 As <strong>the</strong> New Zealand use rate in mushroom houses is 50 mg dichlorvos/m 3 <strong>the</strong>application rate will be 23.6% <strong>of</strong> <strong>the</strong> rate used in <strong>the</strong> Hussey & Hughes study.The regression plot intercept is adjusted downwards to -0.494 (Log 10 [1.358 x0.236 = 0.321 mg/m 3 ]) while <strong>the</strong> slope (-0.0558/hour) is assumed.5.57 No fur<strong>the</strong>r data on plants are available on <strong>the</strong> reduction in DFR, o<strong>the</strong>r than <strong>the</strong>in<strong>for</strong>mation <strong>of</strong> Casida et al. (1962), so it is assumed that beyond 20 minutes aftertreatment, no fur<strong>the</strong>r dissipation from plant surfaces occurs. However, dichlorvosexhibits more persistence on wood, with 65% <strong>of</strong> <strong>the</strong> applied dose remaining after7 hours and 45-55% between days 2-18 (Hussey & Hughes, 1964; in APVMA,2008b). So, <strong>the</strong> use <strong>of</strong> <strong>the</strong> Casida et al. data does contribute some uncertainty in<strong>the</strong> absence <strong>of</strong> more relevant in<strong>for</strong>mation.5.58 By calculating a systemic dose from dermal exposure, <strong>the</strong> residual portion <strong>of</strong> <strong>the</strong>AOEL may be used to find a REI when <strong>the</strong> workplace atmospheric concentration<strong>of</strong> dichlorvos has dropped low enough to allow an 8-hour work-day.5.59 The predicted dermal exposure <strong>for</strong> this scenario when using PPE (hood/visor +overalls over long-sleeved shirt and long-legged trousers + boots + gloves) isbased on <strong>the</strong> UK CRD equation (by adding a factor <strong>for</strong> dermal exposure anddividing by <strong>the</strong> worker‘s body weight) and gives:D = DFR x TC x DA x WR x AR x P / BWD = 0.5 x 2500 x 0.3 x 8 x 1.25 x 0.05 / 70 = 187.5 / 70 = 2.679 μg a.s./kg b.w./day(RQ = 1.9)Where:D = Dermal Exposure [μg a.s./person*d]DFR = Dislodgeable Foliar Residue per kg a.s./ha = 0.5 μg a.s./cm² per kg a.s./haTC = Transfer Coefficient [cm²/person/h] [e.g. Vegetables – Reach/Pick – 2500(UK CRD)Dichlorvos reassessment – application Page 324 <strong>of</strong> 436
DA = percentage dermal absorption [30%], expressed as a fractionWR = Work Rate [8 hours/day]AR = <strong>Application</strong> Rate [1.25 kg a.s./ha]P = Penetration Factor <strong>for</strong> Clothing [= 0.05] German BBA Model <strong>for</strong> re-entrytasks that assumes a Penetration Factor (P) <strong>for</strong> PPE <strong>of</strong> 0.05 (i.e. 95% protection)hood/visor + overalls over long-sleeved shirt and long-legged trousers + boots +glovesBW = bodyweight [70 kg]5.60 After treatment with 50 mg/m 3 <strong>the</strong> estimated dermal exposure is 2.679 μg a.s./kgb.w./day and exceeds <strong>the</strong> AOEL (1.4 μg/kg b.w./day) with a RQ = 1.9, be<strong>for</strong>e anycontribution from inhalation has been considered.5.61 No REI <strong>for</strong> treated mushroom houses can be set <strong>for</strong> an 8-hour work day, based on<strong>the</strong> available in<strong>for</strong>mation.5.62 If working access to mushroom houses is limited to only 2 hours per day, <strong>the</strong>nestimated dermal exposure with PPE reduces to 0.67 μg a.s./kg b.w./day, andinhalation exposure can be estimated.5.63 The remaining AOEL, assuming re-entry workers have not been exposed todichlorvos during o<strong>the</strong>r tasks, (1.4 - 0.67 = 0.73 μg a.s./kg b.w./day) may beassigned to inhalation exposures at a respiration rate <strong>of</strong> 1 m 3 /hour (APVMA,2008b). To convert <strong>the</strong> exposure limit by body weight to an atmospheric level:Inhalation exposure limit (μg a.s./kg b.w./day) x Body wt (kg)Respiration volume (contaminated) (m 3 /hour) x Working day (hours)(0.73 x 70) /( 1 x 2) = 26 μg/m 3[Note: Working day is reduced to 2 hours from <strong>the</strong> default 8.]5.64 In Hussey & Hughes study <strong>the</strong> slope <strong>of</strong> <strong>the</strong> slower second phase <strong>of</strong> dissipationLog 10 concentration vs time plot was -0.0558/hour. This regression line may beused to estimate a REI <strong>for</strong> mushroom houses treated at 50 mg/m 3 , from (Log 10Initial concentration – Log 10 Final concentration) ÷ slope.5.65 If <strong>the</strong> dichlorvos concentration at <strong>the</strong> start is 0.321 mg/m 3 and <strong>the</strong> slope is -0.0558/hour, <strong>the</strong>n <strong>the</strong> time taken <strong>for</strong> <strong>the</strong> concentration to decline to 0.026 mg/m 3will be (-0.494 – [-1.585]) ÷ 0.0558 = 20 hours. This assumes no RPE is used.5.66 If re-entry activities could be limited to 2 hours with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles+ overalls over long-sleeved shirt and long-legged trousers + boots + gloves), aREI <strong>for</strong> mushroom houses treated at 50 mg/m 3 could be set at 48 hours aftertreatment, allowing <strong>for</strong> environmental variation between different structures.Dichlorvos reassessment – application Page 325 <strong>of</strong> 436
[Note: P001132 Nuvos label gives a WHP <strong>of</strong> 3 days <strong>for</strong> ―o<strong>the</strong>r fruit andvegetables‖.]Dichlorvos reassessment – application Page 326 <strong>of</strong> 436
Re-entry into treated enclosed industrial spaces (Scenarios 17-23)5.67 The APVMA used a study by Sch<strong>of</strong>ield (1993; Original not sighted) <strong>for</strong> data ondichlorvos behaviour after fogging industrial buildings (APVMA, 2008b). Thestudy was carried out in a large industrial building fogged to a targetconcentration <strong>of</strong> 85 mg/m 3 . The airborne dichlorvos levels were measured <strong>for</strong> 6hours, and <strong>the</strong>n <strong>the</strong> building was ventilated <strong>for</strong> one hour be<strong>for</strong>e <strong>the</strong> work<strong>for</strong>ce reentered.The half-life <strong>of</strong> airborne dichlorvos over <strong>the</strong> first dissipation phase was1.6 hours. The author‘s regression analysis <strong>of</strong> L n concentration vs time gave <strong>the</strong>Y intercept at 2.996 (or ln [20] mg/m 3 ) and <strong>the</strong> slope [<strong>the</strong> rate <strong>of</strong> loss <strong>of</strong>dichlorvos] was -0.4207/hour. [Sch<strong>of</strong>ield‘s analysis expressed <strong>the</strong> result innatural logarithms.] Sch<strong>of</strong>ield‘s data indicated that <strong>the</strong> dissipation half-life <strong>of</strong>dichlorvos after ventilation slowed to 12.7 hours. [TCL notes <strong>the</strong> finding isunexpected.] The regression analysis <strong>of</strong> L n concentration vs time gave <strong>the</strong> slope[<strong>the</strong> rate <strong>of</strong> loss <strong>of</strong> dichlorvos] as -0.0544/hour. The R 2 <strong>of</strong> <strong>the</strong> second phaseanalysis was 0.74 (first phase, 0.98) indicating considerably more variability anduncertainty in <strong>the</strong> latter values, which may explain <strong>the</strong> finding.5.68 The APVMA (2008b) noted that, based on Sch<strong>of</strong>ield‘s data, after an application<strong>of</strong> RTU gas at <strong>the</strong> Australian label rate <strong>of</strong> 33 mg/m 3 into industrial buildings atoxicologically unacceptable level <strong>of</strong> dichlorvos would persist <strong>for</strong> 3 days, but aREI <strong>of</strong> 4 days could be supportable. However, as <strong>the</strong> New Zealand use rate is 50mg/m 3 , even a 4-day REI may not be supported. Risks <strong>for</strong> <strong>the</strong> New Zealandapplication rate are estimated fur<strong>the</strong>r below (see Tables XVIII & XIX).5.69 It should be noted that product labels (Nuvos, P001132; Divap, P006080)recommend that treated enclosed spaces should be kept closed <strong>for</strong> 10-12 hoursbe<strong>for</strong>e ventilation, and ano<strong>the</strong>r 10-12 hours should elapse be<strong>for</strong>e recommencingwork in <strong>the</strong> buildings.REI <strong>for</strong> workers ventilating industrial buildings after treatment at 50 mg/m 3 :5.70 As <strong>the</strong> main New Zealand use rate is 50 mg dichlorvos/m 3 <strong>for</strong> industrial buildings<strong>the</strong> application rate will be approximately 59% <strong>the</strong> rate used in <strong>the</strong> Sch<strong>of</strong>ieldstudy. The regression plot intercept is adjusted downwards to 2.465 (L n [20 x0.588]) while <strong>the</strong> same slope (-0.4207/h) has been assumed. [Sch<strong>of</strong>ield‘s analysisexpressed <strong>the</strong> result in natural logarithms.]5.71 Taking <strong>the</strong> initial decline in dichlorvos levels, <strong>the</strong> airborne concentration <strong>of</strong>dichlorvos at 10 hours will be:e (2.465 + [-0.4207 x 10]) = 0.175 mg/m 35.72 Re-entering <strong>the</strong> treated building to ventilate it would expose <strong>the</strong> worker byinhalation at approximately 0.175 mg/m 3 . If <strong>the</strong> duration <strong>of</strong> exposure was 30minutes, <strong>the</strong> worst-case upper limit, <strong>the</strong> inhalation exposures with various RPEwould be <strong>the</strong> values set out in Table XVIII:Dichlorvos reassessment – application Page 327 <strong>of</strong> 436
Table XVIII: Re-entry into buildings treated at 50 mg dichlorvos/m 3 – inhalation exposure atventing (10 hours after application)Airbornedichlorvosconc.(mg/m 3 )Duration (h)Exposure(mg) aDose (mg/kg b.w.) bRespiratory protection cNone Half-face Full-face Air-hose0.175 0.5 0.09 0.0013 0.0001
nature <strong>of</strong> <strong>the</strong> building itself, not <strong>the</strong> <strong>for</strong>m in which <strong>the</strong> dichlorvos is applied (gas,fogging solution or aerosol).REI <strong>for</strong> workers ventilating industrial buildings after treatment at 150 mg/m 3 :5.76 Buildings can also be treated at a higher rate, 150 mg dichlorvos/m 3 , <strong>for</strong>cockroaches, fleas etc. (P001132 Nuvos label) (Scenarios 17-23, 24 & 25)(TableXIX):L n Initial concentration [20 x 1.7647] = 35.29e (3.5636 + [-0.4207 x 10]) = 0.526 mg/m 3Table XIX: Re-entry into buildings treated at 150 mg dichlorvos/m 3 – inhalation exposure atventing (10 hours after application)Airbornedichlorvosconc.(mg/m 3 )Duration (h)Exposure(mg) aDose (mg/kg b.w.) bRespiratory protection cNone Half-face Full-face Air-hose0.526 0.5 0.263 0.0038 0.0004 0.0001 NilabcRisk Quotient (RQ) d 2.7 e 0.3 0.07 -Inhalation rate, 1 m 3 /hour;Body weight, 70kg;Protection factors from APVMA, 2008b: factor <strong>of</strong> 0.1 <strong>for</strong> a half face mask and a factor <strong>of</strong> 0.02 <strong>for</strong> afull face mask respectively, and no exposure <strong>for</strong> air-hose (supplied air system) [results rounded];dRQ = Total Estimated Occupational Exposure / AOEL where AOEL = 0.0014 mg/kg b.w./day;eRQ > 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed.5.77 There<strong>for</strong>e, to obtain satisfactory RQ values (
characteristics <strong>of</strong> different buildings (e.g. construction materials & ventingbehaviour).5.79 A REI <strong>for</strong> buildings treated at 150 mg/m 3 (Scenarios 17-23, 24 & 25) should beset at 5 days after <strong>the</strong> onset <strong>of</strong> ventilation, to allow <strong>for</strong> some uncertainties in <strong>the</strong>characteristics <strong>of</strong> different buildings.5.80 For domestic uses (Scenarios 26-29) and uses in public spaces (Scenario 30)estimates <strong>of</strong> exposure and risk are considered in <strong>the</strong> next section on Bystandersand Residents.Dichlorvos reassessment – application Page 330 <strong>of</strong> 436
Conclusions on re-entry worker exposure estimates and risk assessment5.81 Only a few scenarios <strong>for</strong> existing uses <strong>of</strong> dichlorvos gave acceptable risks <strong>for</strong> reentryworkers, and acceptable re-entry generally requires <strong>the</strong> use <strong>of</strong> PPE and/orRPE plus in some cases a Restricted Entry Interval (REI) is also needed.5.82 Re-entry into cereals treated at 0.8kg a.s./ha (Scenarios (3b)(4b)(Table XII) <strong>for</strong>scouting and similar activities are acceptable provided PPE (hood/visor + overallsover long-sleeved shirt and long-legged trousers + boots + gloves) and RPE (atleast a half-face respirator) are worn. All o<strong>the</strong>r outdoor uses (Scenarios 1 & 2,strawberries; Scenarios 3a,c & 4a,c, vegetables & berries; Scenarios 5 & 6, fruit(tamarillo/ persimmons/ berry); Scenarios 7 & 8, passionfruit) were associatedwith unacceptable re-entry risks even with <strong>the</strong> use <strong>of</strong> <strong>the</strong> highest PPE/RPEoptions.5.83 Re-entry <strong>for</strong> ventilation into glasshouses in crop production (Scenarios 9 - 12)treated at 50 mg/m 3 would be acceptable 4 hours after application, if exposure waslimited to 30 minutes, and with <strong>the</strong> use <strong>of</strong> PPE (hood/visor + overalls over longsleevedshirt and long-legged trousers + boots + gloves) and RPE (full-face or airhose).5.84 Re-entry <strong>for</strong> o<strong>the</strong>r tasks (tending/harvesting crops) <strong>of</strong> glasshouses in cropproduction (Scenarios 9 - 12) treated at 50 mg/m 3 would be acceptable if a REI <strong>of</strong>4 hours after <strong>the</strong> onset <strong>of</strong> ventilation (i.e. at least 8 hours after application) wasapplied, and if exposure was limited to only 2 hours per day with <strong>the</strong> use <strong>of</strong> PPE(hat + goggles + overalls over long-sleeved shirt and long-legged trousers + boots+ gloves). [Note <strong>the</strong> REI (like <strong>the</strong> o<strong>the</strong>rs proposed) attempts to allow <strong>for</strong>uncertainties to account <strong>for</strong> <strong>the</strong> characteristics <strong>of</strong> different buildings (e.g.construction materials & venting behaviour).]5.85 Re-entry <strong>for</strong> ventilation into glasshouses or similar facilities used <strong>for</strong> Cymbidiumproduction treated at 1300 or 1800g a.i./ha (52 or 72 mg/m 3 ; Scenarios 13-16)would be acceptable 4 hours after application if exposure was limited to 30minutes, and PPE (hood/visor + overalls over long-sleeved shirt and long-leggedtrousers + boots + gloves) and RPE (full-face or air-hose) were used.5.86 Re-entry <strong>for</strong> o<strong>the</strong>r tasks (tending/harvesting) in glasshouses or similar facilitiesused <strong>for</strong> Cymbidium production treated at <strong>the</strong> lower use rate (1300g a.i./ha or 52mg/m 3 ; Scenarios 13 & 14) would be acceptable if a REI <strong>of</strong> 4 hours after <strong>the</strong>onset <strong>of</strong> ventilation (i.e. at least 8 hours after application) was applied, and ifexposure was limited to only 1 hour per day with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles +overalls over long-sleeved shirt and long-legged trousers + boots + gloves).5.87 Re-entry to mushroom houses (Scenarios 9-12) <strong>for</strong> any purpose would beacceptable if a REI <strong>of</strong> 48 hours after treatment applied, and if exposure waslimited to only 2 hours per day with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles + overalls overlong-sleeved shirt and long-legged trousers + boots + gloves). This proposed REIis based on limited in<strong>for</strong>mation, noting <strong>the</strong> uncertainties about <strong>the</strong> behaviour <strong>of</strong>dichlorvos in /on mushrooms and in mushroom houses.Dichlorvos reassessment – application Page 331 <strong>of</strong> 436
5.88 Re-entry <strong>for</strong> ventilation <strong>of</strong> industrial buildings treated at 50 mg/m 3 (Scenarios 17-23) would be acceptable 10 hours after application if exposure was limited to 30minutes, and RPE (at least half-face) was used.5.89 Re-entry <strong>for</strong> ventilation <strong>of</strong> industrial buildings treated at 150 mg/m 3 (Scenarios17-23, 24 & 25) would be acceptable 10 hours after application if exposure waslimited to 30 minutes, and RPE (at least half-face) was used.5.90 Re-entry <strong>for</strong> o<strong>the</strong>r tasks into industrial buildings treated at 50 mg/m 3 (Scenarios17-23) would be acceptable if a REI <strong>of</strong> 3 days after <strong>the</strong> onset <strong>of</strong> ventilationapplied, with no PPE or RPE required. [Note that this REI also assumes <strong>the</strong>dissipation rates in an unventilated and ventilated building have more to do withdichlorvos and <strong>the</strong> nature <strong>of</strong> <strong>the</strong> building itself, ra<strong>the</strong>r than <strong>the</strong> <strong>for</strong>m in which <strong>the</strong>dichlorvos is applied (gas, fogging solution or aerosol).] While <strong>the</strong> modellingdoes not demonstrate PPE/RPE is required, <strong>the</strong> use <strong>of</strong> some PPE/RPE is goodpractice due to <strong>the</strong> uncertainties in <strong>the</strong> estimates.5.91 Re-entry <strong>for</strong> o<strong>the</strong>r tasks into industrial buildings treated at 150 mg/m 3 (Scenarios17-23, 24 & 25) would be acceptable if a REI <strong>of</strong> 5 days after <strong>the</strong> onset <strong>of</strong>ventilation was applied and in this instance no PPE or RPE would be required.[See Note above in 5.90.] While <strong>the</strong> modelling does not demonstrate PPE/RPE isrequired, <strong>the</strong> use <strong>of</strong> some PPE/RPE is good practice due to <strong>the</strong> uncertainties in <strong>the</strong>estimates.Dichlorvos reassessment – application Page 332 <strong>of</strong> 436
6BYSTANDER & RESIDENT EXPOSURE & RISK ASSESSMENTBystander and resident exposure & risk assessment <strong>for</strong> outdoor usesIntroduction6.1 The main potential sources <strong>of</strong> exposure to <strong>the</strong> general public (bystander orresident) from dichlorvos (o<strong>the</strong>r than via food residues) is via spray drift at <strong>the</strong>time <strong>of</strong> application or from surfaces contaminated ei<strong>the</strong>r by spray drift or directtreatment. Bystander and resident exposures would tend to be intermittent incomparison to exposure <strong>of</strong> workers, who are handling <strong>the</strong> pesticide throughout <strong>the</strong>application. In addition, spray densities, and hence exposure levels drop <strong>of</strong>f withdistance from spraying operations.6.2 TCL notes that any potential bystanders or residents will not be directly handling<strong>the</strong> substance, and <strong>the</strong>y will not be wearing PPE. [Note: amateur, home users arenot considered bystanders or residents while using pesticides.]6.3 UK CRD Bystander Exposure Guidance Document (UK CRD, 2008b) givesmodels <strong>for</strong> estimating bystander exposure in three circumstances:• Exposure from spray drift at <strong>the</strong> time <strong>of</strong> application;• Exposure from inhalation <strong>of</strong> pesticide which volatilises from <strong>the</strong> crop or soilsurface after <strong>the</strong> application has been made; and• Exposure through contact with spray drift contaminated surfaces.6.4 Of <strong>the</strong>se options, <strong>the</strong> Agency has advised TCL that <strong>the</strong> first two approachesshould not be used due to concerns about <strong>the</strong>se models. The UK CRD model <strong>for</strong>exposure through contact with spray drift contaminated surfaces (UK CRD,2008b) is used with <strong>the</strong> addition <strong>of</strong> <strong>the</strong> US EPA model estimate <strong>of</strong> spray driftcontaminated soil/grass ingestion by young children (US EPA, 2006b).Children’s dermal exposure (UK CRD, 2008b)6.5 Systemic exposures via <strong>the</strong> dermal route were calculated using <strong>the</strong> UK CRD(2008b) default drift fallout values (1% from boom sprayers (Scenarios 1-4); 10%from air-assisted sprayers (Scenarios 5 & 6)) and <strong>the</strong> following equation:SE(d) = AR x DF x TTR x TC x H x DA / BWWhere:SE(d) = systemic exposure via <strong>the</strong> dermal routeAR = field application rate (μg/cm 2 )DF = drift fallout valueTTR = turf transferable residuesTC = transfer coefficientH = exposure duration <strong>for</strong> a typical day (hours) – this has been assumed tobe 2 hours which matches <strong>the</strong> 75th percentile <strong>for</strong> toddlers playing on grassDichlorvos reassessment – application Page 333 <strong>of</strong> 436
in <strong>the</strong> EPA Exposure Factors HandbookDA = percent dermal absorption (30%)BW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrsChildren’s hand-to-mouth exposure (UK CRD, 2008b)6.6 Hand-to-mouth exposures were calculated using turf transferable residue levelsusing <strong>the</strong> following equation:SE(h) = AR x DF x TTR x SE x SA x Freq x H / BWWhere:SE(h) = systemic exposure via <strong>the</strong> hand-to-mouth routeAR = field application rate (μg/cm 2 )DF = drift fallout valueTTR = turf transferable residuesSE = saliva extraction factor – <strong>the</strong> default value <strong>of</strong> 50% was usedSA = surface area <strong>of</strong> <strong>the</strong> hands – <strong>the</strong> assumption used here is that 20 cm 2 <strong>of</strong> skinarea is contacted each time a child puts a hand in his or her mouth (this isequivalent to <strong>the</strong> palmar surface <strong>of</strong> three figures; UK CRD default value).Freq = frequency <strong>of</strong> hand to mouth events/hour – <strong>for</strong> short term exposures <strong>the</strong>value <strong>of</strong> 20 events/hours is used, this is <strong>the</strong> 90th percentile <strong>of</strong> observations thatranges from 0 to 70 events/hourH = exposure duration (hours) – this has been assumed to be 2 hours whichmatches <strong>the</strong> 75th percentile <strong>for</strong> toddlers playing on grass in <strong>the</strong> EPA ExposureFactors HandbookBW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrsChildren’s object-to-mouth exposure (UK CRD, 2008b)6.7 Object to mouth exposures were calculated using turf transferable residue levelsusing <strong>the</strong> following equation:SE(o) = AR x DF x TTR x IgR / BWWhere:SE(o) = systemic exposure via mouthing activityAR = field application rate (μg/cm 2 )DF = drift fallout valueTTR = turf transferable residuesIgR = ingestion rate <strong>for</strong> mouthing grass/day – this was assumed to be equivalentto 25cm 2 <strong>of</strong> grass/dayBW = body weight – 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995–7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs.Dichlorvos reassessment – application Page 334 <strong>of</strong> 436
Children’s incidental ingestion <strong>of</strong> soil (US EPA, 2006b)6.8 The approach used to calculate doses that are attributable to soil ingestion is:Where:ADOD = (AR x DF) x F x IgR x SDF / BWADOD = oral dose on day <strong>of</strong> application (mg/kg b.w./day)AR = application rate (mg/cm 2 ) [Note: this value has been modified by <strong>the</strong> DFvalues used in <strong>the</strong> first 3 equations to reflect <strong>the</strong>se spray drift situations, and notdirect turf applications.]F = fraction or residue retained on uppermost 1 cm <strong>of</strong> soil (%) (note: this is anadjustment from surface area to volume)SDF = soil density factor -- volume <strong>of</strong> soil (cm 3 ) per microgram <strong>of</strong> soil;IgR = ingestion rate <strong>of</strong> soil (mg/day)BW = body weight (kg)Assumptions:F - fraction or residue retained on uppermost 1 cm <strong>of</strong> soil is 100 percent based onsoil incorporation into top 1 cm <strong>of</strong> soil after application (1.0/cm)SDF = soil density factor -- volume <strong>of</strong> soil (cm 3 ) per gram <strong>of</strong> soil; to weight 6.7 x10 -4 cm 3 /mg soil)IgR - ingestion rate <strong>of</strong> soil is 100 mg/dayBW - body weight <strong>of</strong> a toddler is 15 kg6.9 These models have been applied to two potential New Zealand use patterns: boomspraying at 0.6 mg/ml (Scenarios 1-4); and, air assisted spraying at 1.026 mg/ml(Scenarios 5 & 6; 7 & 8). <strong>Application</strong>s in passionfruit (Scenarios 7 & 8) arestated to be carried out with knapsack sprayers, and as <strong>the</strong> target is high-level <strong>the</strong>drift fallout value (DF) <strong>for</strong> air assisted spraying (10%) had been used ra<strong>the</strong>r thanground boom value (1%). This approach is likely to be extremely precautionary.6.10 No New Zealand monitoring studies <strong>of</strong> airborne dichlorvos at application sites areavailable to estimate possible public exposure, or modify <strong>the</strong> default assumptions<strong>of</strong> <strong>the</strong>se models. However, some relevant experimental data from Casida et al. ondichlorvos dissipation are available, and <strong>the</strong>se are discussed above in Section 5.5% <strong>of</strong> a 0.1% aqueous 32 P-dichlorvos solution remained on <strong>the</strong> leaf surfaces <strong>of</strong>maize, cotton and peas 20 minutes after application, while about 50% wasvolatilised and 45% absorbed by <strong>the</strong> plant (Casida et al., 1962 in WHO/IPCS,1971; APVMA, 2008b). In which case, <strong>the</strong> TTR turf transferable residue factor in<strong>the</strong> UK CRD equations, which is set at 5% (<strong>the</strong> US EPA default value) needs to bemodified to reflect that <strong>the</strong> Casida et al. data indicates that only 5% is available<strong>for</strong> transfer, while <strong>the</strong> TTR suggests only 5% <strong>of</strong> <strong>the</strong> available remaining residueon <strong>the</strong> foliage is actually transferred. See Appendix 6 and Table XX.6.11 For non-cancer (or toxicological endpoints with thresholds) risks, <strong>the</strong> estimatedexposures to dichlorvos are compared to <strong>the</strong> AOEL (0.0014 mg/kg b.w./day) toDichlorvos reassessment – application Page 335 <strong>of</strong> 436
determine <strong>the</strong> Risk Quotient (RQ). The AOEL was considered <strong>the</strong> mostappropriate benchmark <strong>for</strong> residents as it was based on a 28-day human NOAELwhen repeat dosing would have achieved steady-state levels, and be adequatelyprotective <strong>for</strong> expected residential exposure scenarios.Dichlorvos reassessment – application Page 336 <strong>of</strong> 436
Table XX: Spray driftExposure throughcontact withspray driftcontaminated surfaces(cumulative) (μg/kgb.w./day)ScenarioChild‘s dermalexposureaChild‘s hand-tomou<strong>the</strong>xposureaChild‘s object-tomou<strong>the</strong>xposureaChild‘s soilingestionbBoom sprayers (Scenarios 1-4) c(0.8 kg/ha; 0.6 mg/ml)Exposure(μg/kg b.w./day)Dichlorvos:Bystander Internal Exposure Estimates and Risk Assessment aAir assisted sprayers (Scenarios 5&6) Knapsack sprayers (Scenarios 7&8)(2.052 kg/ha; 1.026 mg/ml) d (1.026 kg/ha; 1.026 mg/ml) dRisk Quotient(RQ) e Exposure(μg/kg b.w./day)Risk Quotient(RQ) eExposure(μg/kg b.w./day)0.0416 1.0670 0.53350.0053 0.1360 0.06800.0013 0.0334 0.0167 1 indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk tothose exposed. [NB: Due to <strong>the</strong> low exposure estimates this table expresses <strong>the</strong> results in micrograms]Dichlorvos reassessment – application Page 337 <strong>of</strong> 436
Bystander and resident exposure & risk assessment <strong>for</strong> indoor horticultural uses andenclosed industrial buildings6.12 Where application is into structures (glass- and mushroom houses and industrialbuildings), bystander exposure should not occur unless an accident occurred or <strong>the</strong>structure was not properly sealed be<strong>for</strong>e treatment.6.13 Intentional or inadvertent venting could result in dichlorvos escaping from <strong>the</strong>treated structure as a point source plume carried by <strong>the</strong> wind until degradation ordeposition. Intentional venting should result in relatively small amounts <strong>of</strong>dichlorvos (vapour) entering <strong>the</strong> atmosphere, in relation to <strong>the</strong> outside airspace,but modelling was not attempted.Resident exposure & risk assessment <strong>for</strong> domestic and public space uses6.14 Where application is into enclosed industrial buildings, bystander exposure shouldnot occur unless an accident happens or <strong>the</strong> structure was not properly sealedbe<strong>for</strong>e treatment. Risks to returning workers are considered in <strong>the</strong> above sectionon Post-application or Re-entry Worker Exposures and Risk Assessment.6.15 However, where application is into domestic buildings, patios/decks or publicspaces individuals may have direct contact with contaminated surfaces andmouthable objects. Children with <strong>the</strong>ir potential <strong>for</strong> high contact, exploratorynature and low body weight appear to be <strong>the</strong> most at risk. Available models will<strong>of</strong>fer worst-case exposure estimates.6.16 The models used previously (§ 6.5-6.8) to estimate children‘s exposure throughcontact with spray drift contaminated surfaces are used, assuming that <strong>the</strong> averagedrift value is 100% (i.e. <strong>the</strong> surface is directly sprayed and <strong>the</strong> spray remainswhere applied) and no dissipation occurs be<strong>for</strong>e and during <strong>the</strong> 2 hours <strong>of</strong> contact.[See Appendix 6 and Table XXI].Table XXI: Dichlorvos – Domestic UsesBystander Internal Exposure Estimates and Risk Assessment aScenarios (26 & 27) Indoor:Exposure through contactwithcontaminatedsurfaces(cumulative)(mg/kg b.w./day)Scenarios (28 & 29)Outdoor:Exposure(mg/kg b.w./day)Child‘s dermalexposure a 1.200Child‘s hand-to-mou<strong>the</strong>xposure a 0.0333Child‘s object-to-mou<strong>the</strong>xposure a 0.0083Child‘s soil ingestion b -Risk Quotient(RQ) cChild‘s total exposure 1.2417 887Child‘s dermalexposure a 1.200Dichlorvos reassessment – application Page 338 <strong>of</strong> 436
Exposure through contactwithcontaminatedsurfaces(cumulative)(mg/kg b.w./day)acChild‘s hand-to-mou<strong>the</strong>xposure a 0.0333Child‘s object-to-mou<strong>the</strong>xposure a 0.0083Child‘s soil ingestion b 0.0011Child‘s total exposure 1.2428 888UK CRD Bystander Exposure Guidance Document (2008b); b US EPA (2006b);Where: Dermal absorption = 30%; Inhalation absorption = 100%;RQ = Estimated Residential Exposure / AOEL where AOEL = 0.0014 mg/kg b.w./day; RQ > 1indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed.6.17 The calculated exposures will have been over-estimated in <strong>the</strong>se models, becauseno dissipation <strong>of</strong> dichlorvos has been factored in due to lack <strong>of</strong> relevantin<strong>for</strong>mation on <strong>the</strong> behaviour <strong>of</strong> dichlorvos after <strong>the</strong> treatment <strong>of</strong> residentialhouses with furniture, s<strong>of</strong>t furnishings etc. (Scenarios 26 & 27). In <strong>the</strong> outdooruses (Scenarios 28 & 29) <strong>the</strong> treated surfaces could be anything from concrete(reported to cause rapid degradation) to wooden decks which may act as areservoir (Hussey & Hughes, 1963 in APVMA, 2008b).6.18 For public space application, children with <strong>the</strong>ir potential <strong>for</strong> high contact,exploratory nature and low body weight appear to be <strong>the</strong> most at risk, andavailable models will <strong>of</strong>fer worst-case exposure estimates.6.19 The models used previously (§ 6.5-6.8) to estimate children‘s exposure throughcontact with spray drift contaminated surfaces are used, assuming that <strong>the</strong> averagedrift value is 100% (i.e. <strong>the</strong> surface is directly sprayed and <strong>the</strong> spray remainswhere applied) and no dissipation occurs be<strong>for</strong>e and during <strong>the</strong> 2 hours <strong>of</strong> contact.[See Appendix 6 and Table XXII].Scenario (30) Indoor:Table XXII: Dichlorvos – Public Space Uses (1 hectare)Bystander Internal Exposure Estimates and Risk Assessment aExposure through contactwithcontaminatedsurfaces(cumulative)(mg/kg b.w./day)acExposure(mg/kg b.w./day)Child‘s dermalexposure a 0.104Child‘s hand-to-mou<strong>the</strong>xposure a 0.0133Child‘s object-to-mou<strong>the</strong>xposure a 0.0033Child‘s soil ingestion b 0.0001Risk Quotient(RQ) cChild‘s total exposure 0.1207 86UK CRD Bystander Exposure Guidance Document (2008b); b US EPA (2006b);Where: Dermal absorption = 30%; Inhalation absorption = 100%;RQ = Estimated Residential Exposure / AOEL where AOEL = 0.0014 mg/kg b.w./day; RQ > 1Dichlorvos reassessment – application Page 339 <strong>of</strong> 436
indicates <strong>the</strong> likelihood <strong>of</strong> an unacceptable risk to those exposed.6.20 Again, <strong>the</strong> calculated exposures will have been over-estimated in <strong>the</strong>se models,because no dissipation <strong>of</strong> dichlorvos has been factored in due, in part, to <strong>the</strong>complexity <strong>of</strong> what constitutes public spaces that may include concrete, parks,beaches, play grounds etc. (Scenario 30).Dichlorvos reassessment – application Page 340 <strong>of</strong> 436
Conclusions on bystander and residential exposure estimates from spray drift:6.21 No reliable exposure models were available to assess bystander exposures tospray drift at time <strong>of</strong> application or inhalation <strong>of</strong> volatilised pesticides followingapplication.6.22 Residential exposure estimates from outdoor uses <strong>of</strong> dichlorvos were estimated byconsidering risks to young children from surfaces contaminated by spray drift.The risks were calculated to be acceptable after boom sprayer use at 0.8 kg a.i./ha(Scenarios 1-4), and from air assisted sprayers at 2.052 or 1.026 kg dichlorvos/ha(Scenarios 5-6 and 7-8) (see Table XX).6.23 <strong>Application</strong>s into structures (glass- and mushroom houses, Scenarios 13-16; andindustrial buildings, Scenarios 17-25) should not result in bystander exposureunless an accident occurred or <strong>the</strong> structure was not properly sealed be<strong>for</strong>etreatment.6.24 Intentional or inadvertent venting from <strong>the</strong> treated structure could result indichlorvos escaping as a point source plume carried by <strong>the</strong> wind until degradationor deposition, but modelling was not attempted. The amounts <strong>of</strong> dichlorvos fromeach individually treated facility would be relatively small in relation to <strong>the</strong>outside airspace.6.25 Estimated exposures to children after domestic uses indoors (Scenarios 26 & 27)and outdoors (Scenarios 28 & 29) indicate very high risks (RQs <strong>of</strong> >>1,) couldresult from contact with contaminated surfaces (i.e. from carpets, s<strong>of</strong>t furnishings,floors etc.). While <strong>the</strong> calculated exposures will have been over-estimated in<strong>the</strong>se models, because no dissipation <strong>of</strong> dichlorvos has been factored in [see TableXXI], <strong>the</strong> risk levels are unacceptably high.6.26 Estimated exposures to children after public space applications (Scenario 30)indicate very high risk (RQs <strong>of</strong> >>1) could result from contact with contaminatedsurfaces (i.e. from playing on sprayed turf). While, <strong>the</strong> calculated exposures willhave been over-estimated in <strong>the</strong>se models, because no dissipation <strong>of</strong> dichlorvoshas been factored in [see Table XXII], <strong>the</strong> risk levels are unacceptably high.Dichlorvos reassessment – application Page 341 <strong>of</strong> 436
7 SUMMARY AND CONCLUSIONS7.1 TCL estimated occupational exposures to dichlorvos from proposed outdoor andindoor uses summarised in <strong>the</strong> following Table (XXIII).Table XXIII: Dichlorvos Use ScenariosScenario Crop/Use Method Rate <strong>Application</strong>sOutdoorEquipment Details Formu-lation<strong>Application</strong>rateArea orvolumetreatedNo. peryearInterval(days)1 Strawberries Low boom Fine – EC 800 20 ha 1 -mediumg a.i./ha2 droplet2 73 Vegetables, High boom Fine – EC 800 20 ha 1 -cereals,mediumg a.i./ha4 berriesdroplet2 75 FruitAirblast FinemediumEC 2052 8 ha 1 -6g a.i./haberry)(tamarillo/persimmons/droplet2 79 Glasshouse Automatic Fog RTU 0.05 25000 m 3 1 -crops/ applicationgas g/m 3 (1.25 ha)10mushrooms2 711 EC 1 -Fog12 2 713 Glasshouse Automatic Fog/low EC 1300 0.1 ha 1 -flowers application volumeg a.i./ha (2500 m 3 )14 (Cymbidium)mister2 77 Passionfruit Knapsack Finemediumg a.i./haEC 1026 1 ha 1 -8 droplet2 715 Hand held Finemediumg a.i./ha (5000 m 3 )EC 1800 0.2 ha 1 -sprayer16 droplet2 7Indoor17 Enclosed Automatic Fog RTU 0.05 & 0.15 375, 1 -space applicationgas g a.i./ m 3 3750 &18 (industrial)12500 2 7m 3 )19 Manual Fog RTU 0.05 & 0.151 -Foggergas g a.i./ m 3 2 720 Automatic Fog EC 0.05 & 0.151 -21applicationg a.i./ m 32 7Dichlorvos reassessment – application Page 342 <strong>of</strong> 436
Table XXIII: Dichlorvos Use ScenariosScenario Crop/Use Method Rate <strong>Application</strong>sEquipment Details Formu-lation<strong>Application</strong>rateArea orvolumetreatedNo. peryearInterval(days)22 Manual Fog EC 0.05 & 0.151 -23foggerg a.i./ m 32 724 High Fine- EC 0.1 & 0.3 150, 1 -pressure mediumg a.i./ m 2 1500 &25 hand-wand droplet2500 m 2 2 7orequivalent26 Domestic use RTU Aerosol 3.1 0.25 g 7.44 m 2 1 -aerosol (manual g a.i./L a.i./m 227 )2 728 Knapsack FinemediumRTU 0.3 g a.i./m 2 60 m 2 1 -29liquida.i./L;4Lpack)droplet (4.4g2 7Outdoor – public space30 Public outdooruseManualfoggerFog EC 1500 ga.i./ha1 ha 1 -Operator exposures and risk assessment:7.2 Scenarios 1-16 give unacceptable risks <strong>for</strong> operators (mixer/loader/applicators),even with PPE, RPE and engineering controls, where appropriate, except <strong>for</strong>Scenarios (9 & 10) (automated fogging operations with RTU gas in glasshouses insome cases) and Scenarios (13 & 14) (automated fogging with EC solutions inCymbidium production, with restrictions). No outdoor uses <strong>of</strong> dichlorvos instrawberries, vegetables, cereal berries, fruit trees or passion fruit gave acceptableoperator risk estimates (Scenarios 1-8).7.3 Vegetables/Mushrooms: RTU dichlorvos gas through automatic spray systems at50 mg/m 3 may be used <strong>for</strong> <strong>the</strong> fogging <strong>of</strong> glasshouse crops/ mushrooms(Scenarios 9 & 10), provided: work day exposure is limited to <strong>the</strong> use <strong>of</strong> only onedichlorvos gas cylinder, and half-face respirator, chemical-resistant gloves,overalls, eye protection and boots are worn. Two dichlorvos gas cylinders, as amaximum, can be handled in a day (see Table VI) provided: a full-face respirator,chemical-resistant gloves, overalls, eye protection and boots are worn duringcylinder changeover. The cylinder change over restriction means that only small(approximately 0.25 ha) spaces can be treated with 7 L cylinders, but treatment <strong>of</strong>larger spaces (up to 1.25 ha) is possible using 35L cylinders using automatedsystems.Dichlorvos reassessment – application Page 343 <strong>of</strong> 436
7.4 Cymbidium: EC dichlorvos solutions through automatic spray systems at 1.3kga.i./ha may be used <strong>for</strong> fogging glasshouses during Cymbidium production(Scenarios 13 & 14), provided: work day exposure is limited to 0.1ha (1,000m 2 ),and a respirator <strong>of</strong> at least A1P2 specification, eye protection and chemicalresistant gloves are worn during mixing/loading. Automated treatment or manualfine spray application at 1.8 kg a.i./ha in glasshouses <strong>for</strong> Cymbidium productiondo not give acceptable risk estimates..7.5 As can be seen from Tables VI-VIII above, some <strong>of</strong> <strong>the</strong> enclosed spaceapplications give acceptable risks <strong>for</strong> operators if adequate PPE and RPE areworn. In some cases <strong>the</strong> length <strong>of</strong> work exposure (area/volume treated) also needsto be limited.7.6 RTU dichlorvos gas through automatic spray systems at 50 mg/m 3 may be used<strong>for</strong> <strong>the</strong> fogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 375 or 3750 m 3 (Scenarios 17 &18; Table VI), provided: work day exposure is limited to <strong>the</strong> use <strong>of</strong> only onedichlorvos gas cylinder, and half-face respirator, chemical-resistant gloves,overalls, eye protection and boots are worn during cylinder changeover. RTUdichlorvos gas through automatic spray systems at 50 mg/m 3 may be used <strong>for</strong> <strong>the</strong>fogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 12500 m 3 (Scenarios 17 & 18), provided:work day exposure is limited to <strong>the</strong> use <strong>of</strong> only two dichlorvos gas cylinders, andfull-face respirator, chemical-resistant gloves, overalls, eye protection and bootsare worn during cylinder changeover. Thus Scenarios 17 and 18 give acceptablerisk estimates <strong>for</strong> all treatment volumes, provided sufficient PPE/RPE is worn.7.7 <strong>Application</strong> <strong>of</strong> RTU dichlorvos gas at 50 mg/m 3 may be used <strong>for</strong> <strong>the</strong> manualfogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 375 m 3 (Scenarios 19; Table VI),provided: work day exposure is limited to 1.5 minutes exposure, <strong>the</strong> use <strong>of</strong> onlyone dichlorvos gas cylinder, and half-face respirator and chemical-resistant glovesare worn during cylinder changeover.7.8 <strong>Application</strong> <strong>of</strong> RTU dichlorvos gas at 50 mg/m 3 may be used <strong>for</strong> <strong>the</strong> manualfogging <strong>of</strong> enclosed industrial spaces <strong>of</strong> 3750 m 3 (Scenarios 19; Table VI),provided: work day exposure is limited to 15 minutes exposure, <strong>the</strong> use <strong>of</strong> onlyone dichlorvos gas cylinder, a half-face respirator and chemical-resistant glovesare worn during cylinder changeover, and air-hose respirator or SCBA, chemicalresistantgloves, chemical-resistant full-body suit, eye protection and boots areworn during application. Thus <strong>for</strong> Scenario 19, manual treatment <strong>of</strong> largervolumes (≥3750 m 3 ) does not give acceptable estimates even with air hose RPEduring application. The risk estimate is primarily driven by <strong>the</strong> APVMA cylinderchange exposure estimates which mean that <strong>the</strong> use <strong>of</strong> two cylinders per day isunacceptable even with PPE/RPE during changeover.7.9 Mixing/loading fogging solutions at 0.05g a.i./m 3 <strong>for</strong> application throughautomatic spray systems into enclosed industrial spaces <strong>of</strong> 375 m 3 (Scenarios 20& 21; Table VII) may be done, provided: work day exposure is limited to <strong>the</strong>specified volume, and a respirator <strong>of</strong> at least A1P2 specification, chemicalresistantgloves, overalls, eye protection and boots are worn duringDichlorvos reassessment – application Page 344 <strong>of</strong> 436
mixing/loading. Mixing/loading fogging solutions at 0.15g a.i./m 3 <strong>for</strong> applicationthrough automatic spray systems into enclosed industrial spaces <strong>of</strong> 375 m 3(Scenarios 20 & 21) may be done, provided: work day exposure is limited to <strong>the</strong>specified volume, and a respirator <strong>of</strong> at least A1P2 specification, chemicalresistantgloves, overalls, eye protection and boots are worn duringmixing/loading. Thus <strong>for</strong> Scenarios 20 & 21, only <strong>the</strong> smallest treatment volumesgive acceptable risk estimates due to <strong>the</strong> exposure during mixing/loading, but notlarger volumes (≥3750 m 3 ).7.10 Manual application <strong>of</strong> fogging solutions at 0.05 or 0.15g a.i./m 3 into enclosedindustrial spaces <strong>of</strong> 375 m 3 (Scenarios 22 & 23; Table VII), may be doneprovided: work day exposure is limited <strong>the</strong> specified volume, and half-facerespirator (at least A1P2 specification), chemical-resistant gloves, overalls, eyeprotection and boots are worn during mixing/loading and application. Thus <strong>for</strong>Scenarios 22 & 23, only <strong>the</strong> smallest treatment volumes give acceptable riskestimates primarily due to <strong>the</strong> exposure during mixing/loading.7.11 The surface spraying <strong>of</strong> <strong>the</strong> smallest space 150 m 2 at 0.1g a.i./m 2 using highpressure handwand (Scenarios 24 & 25; Table VIII), may be done provided: workday exposure is limited <strong>the</strong> specified area, and a half-face respirator, chemicalresistantgloves, chemical-resistant full-body suit, eye protection and boots areworn during mixing/loading and application.7.12 The surface spraying <strong>of</strong> <strong>the</strong> smallest space 150 m 2 at 0.30g a.i./m 2 using highpressure handwand (Scenarios 24 & 25; Table VIII), may be done provided: workday exposure is limited <strong>the</strong> specified area, and air-hose respirator or SCBA,chemical-resistant gloves, chemical-resistant full-body suit, eye protection andboots are worn during mixing/loading and application. Thus <strong>for</strong> Scenarios 24 &25, surface spraying <strong>of</strong> larger spaces (1500 or 2500 m 2 ) at ei<strong>the</strong>r application rategive unacceptable risk estimates primarily due to <strong>the</strong> exposure duringmixing/loading.7.13 Both <strong>the</strong> domestic uses that are assumed to be carried out by amateurs without <strong>the</strong>use <strong>of</strong> PPE or RPE, surface/crevice RTU gas applications indoors over 7.44m 2(Scenarios 26 & 27) and larger outdoor spaces with RTU spray-mixes and aknapsack sprayer (Scenarios 28 & 29) are predicted to give unacceptable risks.7.14 The public space application (Scenario 30) (<strong>for</strong> pr<strong>of</strong>essional applicators) gives anunacceptable risk even <strong>for</strong> only 1 hectare when wearing a chemical resistant fullbodysuit and air-hose RPE or SCBA.Re-entry worker exposures and risk assessment:7.15 Only a few scenarios <strong>for</strong> existing uses <strong>of</strong> dichlorvos gave acceptable risks <strong>for</strong> reentryworkers, and acceptable re-entry generally requires <strong>the</strong> use <strong>of</strong> PPE and/orRPE plus in some cases a Restricted Entry Interval (REI) is also needed.Dichlorvos reassessment – application Page 345 <strong>of</strong> 436
7.16 Re-entry into cereals treated at 0.8kg a.s./ha (Scenarios (3b)(4b)(Table XII) <strong>for</strong>scouting and similar activities are acceptable provided PPE (hood/visor + overallsover long-sleeved shirt and long-legged trousers + boots + gloves) and RPE (atleast a half-face respirator) are worn. All o<strong>the</strong>r outdoor uses (Scenarios 1 & 2,strawberries; Scenarios 3a,c & 4a,c, vegetables & berries; Scenarios 5 & 6, fruit(tamarillo/ persimmons/ berry); Scenarios 7 & 8, passionfruit) were associatedwith unacceptable re-entry risks even with <strong>the</strong> use <strong>of</strong> <strong>the</strong> highest PPE/RPEoptions.7.17 Re-entry <strong>for</strong> ventilation into glasshouses in crop production (Scenarios 9 - 12)treated at 50 mg/m 3 would be acceptable 4 hours after application, if exposure waslimited to 30 minutes, and with <strong>the</strong> use <strong>of</strong> PPE (hood/visor + overalls over longsleevedshirt and long-legged trousers + boots + gloves) and RPE (full-face or airhose).7.18 Re-entry <strong>for</strong> o<strong>the</strong>r tasks (tending/harvesting crops) <strong>of</strong> glasshouses in cropproduction (Scenarios 9 - 12) treated at 50 mg/m 3 would be acceptable if a REI <strong>of</strong>4 hours after <strong>the</strong> onset <strong>of</strong> ventilation (i.e. at least 8 hours after application) wasapplied, and if exposure was limited to only 2 hours per day with <strong>the</strong> use <strong>of</strong> PPE(hat + goggles + overalls over long-sleeved shirt and long-legged trousers + boots+ gloves). [Note <strong>the</strong> REI (like <strong>the</strong> o<strong>the</strong>rs proposed) attempts to allow <strong>for</strong>uncertainties to account <strong>for</strong> <strong>the</strong> characteristics <strong>of</strong> different buildings (e.g.construction materials & venting behaviour).]7.19 Re-entry <strong>for</strong> ventilation into glasshouses or similar facilities used <strong>for</strong> Cymbidiumproduction treated at 1300 or 1800g a.i./ha (52 or 72 mg/m 3 ; Scenarios 13-16)would be acceptable 4 hours after application if exposure was limited to 30minutes, and PPE (hood/visor + overalls over long-sleeved shirt and long-leggedtrousers + boots + gloves) and RPE (full-face or air-hose) were used.7.20 Re-entry <strong>for</strong> o<strong>the</strong>r tasks (tending/harvesting) in glasshouses or similar facilitiesused <strong>for</strong> Cymbidium production treated at <strong>the</strong> lower use rate (1300g a.i./ha or 52mg/m 3 ; Scenarios 13 & 14) would be acceptable if a REI <strong>of</strong> 4 hours after <strong>the</strong>onset <strong>of</strong> ventilation (i.e. at least 8 hours after application) was applied, and ifexposure was limited to only 1 hour per day with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles +overalls over long-sleeved shirt and long-legged trousers + boots + gloves).7.21 Re-entry to mushroom houses (Scenarios 9-12) <strong>for</strong> any purpose would beacceptable if a REI <strong>of</strong> 48 hours after treatment applied, and if exposure waslimited to only 2 hours per day with <strong>the</strong> use <strong>of</strong> PPE (hat + goggles + overalls overlong-sleeved shirt and long-legged trousers + boots + gloves). This proposed REIis based on limited in<strong>for</strong>mation, noting <strong>the</strong> uncertainties about <strong>the</strong> behaviour <strong>of</strong>dichlorvos in /on mushrooms and in mushroom houses.7.22 Re-entry <strong>for</strong> ventilation <strong>of</strong> industrial buildings treated at 50 mg/m 3 (Scenarios 17-23) would be acceptable 10 hours after application if exposure was limited to 30minutes, and RPE (at least half-face) was used.Dichlorvos reassessment – application Page 346 <strong>of</strong> 436
7.23 Re-entry <strong>for</strong> ventilation <strong>of</strong> industrial buildings treated at 150 mg/m 3 (Scenarios17-23, 24 & 25) would be acceptable 10 hours after application if exposure waslimited to 30 minutes, and RPE (at least half-face) was used.7.24 Re-entry <strong>for</strong> o<strong>the</strong>r tasks into industrial buildings treated at 50 mg/m 3 (Scenarios17-23) would be acceptable if a REI <strong>of</strong> 3 days after <strong>the</strong> onset <strong>of</strong> ventilationapplied, with no PPE or RPE required. [Note that this REI also assumes <strong>the</strong>dissipation rates in an unventilated and ventilated building have more to do withdichlorvos and <strong>the</strong> nature <strong>of</strong> <strong>the</strong> building itself, ra<strong>the</strong>r than <strong>the</strong> <strong>for</strong>m in which <strong>the</strong>dichlorvos is applied (gas, fogging solution or aerosol).] While <strong>the</strong> modellingdoes not demonstrate PPE/RPE is required, <strong>the</strong> use <strong>of</strong> some PPE/RPE is goodpractice due to <strong>the</strong> uncertainties in <strong>the</strong> estimates.7.25 Re-entry <strong>for</strong> o<strong>the</strong>r tasks into industrial buildings treated at 150 mg/m 3 (Scenarios17-23, 24 & 25) would be acceptable if a REI <strong>of</strong> 5 days after <strong>the</strong> onset <strong>of</strong>ventilation was applied and in this instance no PPE or RPE would be required.[See Note above in 5.90.] While <strong>the</strong> modelling does not demonstrate PPE/RPE isrequired, <strong>the</strong> use <strong>of</strong> some PPE/RPE is good practice due to <strong>the</strong> uncertainties in <strong>the</strong>estimates.Bystander and resident exposures and risk assessment:7.26 No reliable exposure models were available to assess bystander exposures tospray drift at time <strong>of</strong> application or inhalation <strong>of</strong> volatilised pesticides followingapplication.7.27 Residential exposure estimates from outdoor uses <strong>of</strong> dichlorvos were estimated byconsidering risks to young children from surfaces contaminated by spray drift.The risks were calculated to be acceptable after boom sprayer use at 0.8 kg a.i./ha(Scenarios 1-4), and from air assisted sprayers at 2.052 or 1.026 kg dichlorvos/ha(Scenarios 5-6 and 7-8) (see Table XX).7.28 <strong>Application</strong>s into structures (glass- and mushroom house, Scenarios 13-16; andindustrial buildings, Scenarios 17-25) should not result in bystander exposureunless an accident occurred or <strong>the</strong> structure was not properly sealed be<strong>for</strong>etreatment.7.29 Intentional or inadvertent venting from <strong>the</strong> treated structure could result indichlorvos escaping as a point source plume carried by <strong>the</strong> wind until degradationor deposition, but modelling was not attempted. The amounts <strong>of</strong> dichlorvos fromeach individually treated facility would be relatively small in relation to <strong>the</strong>outside airspace.7.30 Estimated exposures to children after domestic uses indoors (Scenarios 26 & 27)and outdoors (Scenarios 28 & 29) indicate very high risks (RQs <strong>of</strong> >>1,) couldresult from contact with contaminated surfaces (i.e. from carpets, s<strong>of</strong>t furnishings,floors etc.). While <strong>the</strong> calculated exposures will have been over-estimated in<strong>the</strong>se models, because no dissipation <strong>of</strong> dichlorvos has been factored in [see TableXXI], <strong>the</strong> risk levels are unacceptably high.Dichlorvos reassessment – application Page 347 <strong>of</strong> 436
7.31 Estimated exposures to children after public space applications (Scenario 30)indicate very high risk (RQs <strong>of</strong> >>1) could result from contact with contaminatedsurfaces (i.e. from playing on sprayed turf). While, <strong>the</strong> calculated exposures willhave been over-estimated in <strong>the</strong>se models, because no dissipation <strong>of</strong> dichlorvoshas been factored in [see Table XXII], <strong>the</strong> risk levels are unacceptably high.Dichlorvos reassessment – application Page 348 <strong>of</strong> 436
REFERENCES:APVMA, 2008a. ―DICHLORVOS - Toxicology Assessment: The reconsideration <strong>of</strong>approvals <strong>of</strong> <strong>the</strong> active constituent, registrations <strong>of</strong> products containing dichlorvos andapprovals <strong>of</strong> <strong>the</strong>ir associated labels.‖ Australian Pesticides & Veterinary MedicinesAuthority, KINGSTON ACT 2604; 2008.APVMA, 2008b. ―DICHLORVOS - OCCUPATIONAL HEALTH AND SAFETYASSESSMENT: The reconsideration <strong>of</strong> approvals <strong>of</strong> <strong>the</strong> active constituent, registrations<strong>of</strong> products containing dichlorvos and approvals <strong>of</strong> <strong>the</strong>ir associated labels.‖ AustralianPesticides & Veterinary Medicines Authority, KINGSTON ACT 2604; 2008.ATSDR, 1997. ―TOXICOLOGICAL PROFILE FOR DICHLORVOS‖ Agency <strong>for</strong>Toxic <strong>Substance</strong>s and Disease Registry, Atlanta, Georgia 30333; 1997.CalDPR, 1996. ―DICHLORVOS (DDVP): RISK CHARACTERIZATIONDOCUMENT.‖ Medical Toxicology and Worker Health and Safety Branches,Department <strong>of</strong> Pesticide Regulation, Cali<strong>for</strong>nia Environmental Protection Agency.Franklin, C. & Worgan, J.P., 2005. ―Occupational and Residential ExposureAssessment <strong>for</strong> Pesticides.‖ John Wiley and Sons; ISBN 0471489891, 9780471489894.[Abstract only]UK CRD, 1992. ―Uni<strong>for</strong>m Principles <strong>for</strong> Safeguarding <strong>the</strong> Health <strong>of</strong> Applicators <strong>of</strong>Plant Protection Products.‖ Biologische Bundesanstalt für Land- und Forstwirtschaft,Bundesgesundheitsamt, und Industrieverband Agrar e.V. ISBN 3489-27700-7. 1992;http://www.pesticides.gov.uk/uploadedfiles/Web_Assets/PSD/German_Model_PSD1.xls [pr<strong>of</strong>essional mixer/loader/applicator models]UK CRD, 2006; [Amateur: Aerosol Surface Treatment Model]http://www.pesticides.gov.uk/uploadedfiles/Web_Assets/PSD/Amateur%20use%20model2.xlsUK CRD, 2007; [Revised UK Predictive Operator Exposure Model (UK POEM): homegarden model]http://www.pesticides.gov.uk/uploadedfiles/Web_Assets/PSD/UK_POEM_07.xlsUK CRD, 2008a. ―GUIDANCE FOR POST-APPLICATION (RE-ENTRY WORKER)EXPOSURE ASSESSMENT.‖http://www.pesticides.gov.uk/approvals.asp?id=2422&link=%2Fuploadedfiles%2FWeb%5FAssets%2FPSD%2FRe%2Dentry%2520worker%2520guidance%5Ffinal%2520version%2EpdfUK CRD, 2008b. ―BYSTANDER EXPOSURE GUIDANCE.‖http://www.pesticides.gov.uk/approvals.asp?id=2428&link=%2Fuploadedfiles%2FWeb%5FAssets%2FPSD%2FBystander%2520exposure%2520guidance%5Ffinal%2520version%2EpdfDichlorvos reassessment – application Page 349 <strong>of</strong> 436
UK CRD, 2008c. ―OPERATOR EXPOSURE GUIDANCE FOR AMATEUR (HOMEGARDEN) PESTICIDES.‖http://www.pesticides.gov.uk/uploadedfiles/Web_Assets/PSD/Amateur%20use%20guidance%202.pdfUS EPA, 1997. ―Standard Operating Procedures (SOPs) <strong>for</strong> Residential ExposureAssessments.‖ Contract No. 68-W6-0030; Work Assignment No. 3385.102 [trac6a05]US EPA, 2000. ―Worker Risk Mitigation <strong>for</strong> Organophosphate Pesticides.‖ PesticideRegistration (PR) Notice 2000-9 September 29, 2000.US EPA, 2006a. ―Reregistration Eligibility Decision <strong>for</strong> Dichlorvos (DDVP).‖ Office<strong>of</strong> Pesticide Programs, UNITED STATES ENVIRONMENTAL PROTECTIONAGENCY, WASHINGTON D.C., 20460.WHO/IPCS, 1971. ―1970 EVALUATIONS OF SOME PESTICIDE RESIDUES INFOOD.‖ AGP:1970/M/12/1; WHO/FOOD ADD/71.42Dichlorvos reassessment – application Page 350 <strong>of</strong> 436
Appendix 1:Occupational Exposure Estimates & Risk Assessment with Engineering ControlsPossible engineering controls reported by US EPA (2000) <strong>for</strong> mitigation <strong>of</strong> workerexposure risks to organophosphate (OP) pesticides: [Edited <strong>for</strong> relevance to proposeddichlorvos applications.]―1. Contained/Closed Mixing and Loading Systems―One engineering control available <strong>for</strong> mixing and loading pesticides is a closed system.By closed system EPA means a system designed by <strong>the</strong> manufacturer to enclose <strong>the</strong>pesticide to prevent it from contacting individuals while it is being handled. Under <strong>the</strong>WPS [Worker Protection Standard], when a closed mixing and loading system is usedcorrectly and maintained according to <strong>the</strong> manufacturers‘ operating instructions,handlers may reduce some <strong>of</strong> <strong>the</strong> personal protective equipment listed on <strong>the</strong> pesticidelabeling <strong>for</strong> mixing and loading activities.“a. Mechanical Transfer System. One type <strong>of</strong> closed system <strong>for</strong> liquid <strong>for</strong>mulations isa mechanical transfer system that consists <strong>of</strong> a probe that is inserted into <strong>the</strong> pesticidecontainer and seals tightly to <strong>the</strong> pesticide container to prevent liquid (but notnecessarily any vapor) from contacting handlers or o<strong>the</strong>r people. The pesticide is ei<strong>the</strong>rtransferred directly from its container to a spray tank, or <strong>the</strong> container is connecteddirectly to <strong>the</strong> spray system. Mixers and loaders using this closed system are permittedto wear reduced PPE. A mechanical transfer system usually does not meet <strong>the</strong> definition<strong>of</strong> a closed system <strong>under</strong> <strong>the</strong> WPS unless inhalation exposure is not a concern; howeverit is considered an engineering control which greatly reduces dermal exposure.“b. Dry Disconnect System. A dry-disconnect system does not meet <strong>the</strong> definition <strong>of</strong> aclosed system <strong>under</strong> WPS unless it is part <strong>of</strong> a mechanical closed system. Drydisconnect systems are considered to be an engineering control that reduces potentialworker exposure by reducing leakage <strong>of</strong> liquid when pipes or hoses are uncoupled fromequipment or from o<strong>the</strong>r pipes or hoses. Dry-disconnect systems involve fittingsdesigned by <strong>the</strong> manufacturer to minimize pesticide leakage at each hose disconnectpoint. These systems are <strong>of</strong>ten used in conjunction with mechanical transfer systems.‖“2. Enclosed Cabs“a. Enclosed Cabs <strong>for</strong> <strong>Application</strong> and Flagging. The engineering control available<strong>for</strong> handlers applying pesticides using motorized ground equipment or flagging tosupport aerial applications is an enclosed cab. By enclosed cab, EPA means a cabhaving a nonporous barrier that totally surrounds <strong>the</strong> occupants and prevents contactwith pesticides outside <strong>of</strong> <strong>the</strong> cab. By definition, all enclosed cabs protect againstdermal exposure. Some enclosed cabs also provide respiratory protection -- <strong>the</strong>y can beequipped with a ventilation system that provides particulate filtration equivalent to aNIOSH-approved dust/mist respirator or that provides organic-vapor-removing andparticulate filtration equivalent to a NIOSH-approved organic-vapor-removingDichlorvos reassessment – application Page 351 <strong>of</strong> 436
espirator with a dust/mist prefilter. The per<strong>for</strong>mance criteria <strong>for</strong> enclosed cabs arefound in <strong>the</strong> WPS at 40 CFR Part 170.240(d)(5).―If <strong>the</strong> occupational risk assessment <strong>for</strong> such handlers indicates that dermal exposure is<strong>the</strong> only exposure route <strong>of</strong> concern (i.e., inhalation risks are not a concern even when norespirator is worn), <strong>the</strong>n an enclosed cab providing only dermal protection is sufficientlyprotective and will be required on <strong>the</strong> pesticide labeling. However, if <strong>the</strong> riskassessment indicates that inhalation risks are a concern unless an appropriate respiratoris worn, <strong>the</strong>n <strong>the</strong> pesticide labeling will indicate that <strong>the</strong> enclosed cab must providerespiratory protection equivalent to <strong>the</strong> type <strong>of</strong> respirator required <strong>for</strong> <strong>the</strong> pesticide orthat <strong>the</strong> handler must wear <strong>the</strong> appropriate respirator while inside <strong>the</strong> enclosed cab …depending on <strong>the</strong> severity <strong>of</strong> inhalation risks, EPA may require that enclosed cabs meetper<strong>for</strong>mance criteria beyond those specified in <strong>the</strong> WPS.―Under <strong>the</strong> WPS, handlers in any enclosed cab need not wear all <strong>of</strong> <strong>the</strong> label-requiredPPE designed <strong>for</strong> dermal protection (e.g., double layer body protection, or chemicalresistantgloves, footwear, or headgear), provided such PPE is immediately available <strong>for</strong>use if <strong>the</strong> handler exits <strong>the</strong> enclosed cab in <strong>the</strong> treated area and contacts treated surfaces.If <strong>the</strong> manufacturer or a government agency declares that <strong>the</strong> enclosed cab providesrespiratory protection equivalent to <strong>the</strong> label-required respirator (and certain use andmaintenance conditions are met), handlers need not wear <strong>the</strong> respirator while in <strong>the</strong>enclosed cab. However, <strong>the</strong> appropriate respirator must be immediately available <strong>for</strong> useif <strong>the</strong> handler exits <strong>the</strong> cab within <strong>the</strong> treated area.‖ (US EPA, 2000)Effects <strong>of</strong> various engineering controls on pesticide exposure.The effects <strong>of</strong> engineering controls on default modelled occupational exposure estimatesand risk assessments <strong>for</strong> boom and air-blast sprayers are given in <strong>the</strong> Table below. Thefactors used and descriptions <strong>of</strong> <strong>the</strong> engineering controls are also listed.All data are unit exposure values (μg/kg <strong>of</strong> active ingredient (a.i.) handled), taken fromPHED (1992). Values are central tendency measures based on high confidence datasets. dFactorExposure (μg/kg a.i. handled)Ground boomEngineering controls Closed cab 11.0<strong>for</strong> ground-boom applicator a Open cab 33.0[Closed cab is assumed to <strong>of</strong>fer 11/33 = 0.33 or 3x <strong>the</strong> protection factor vis-à-vis Opencabs <strong>for</strong> ground-boom applicators.]Dichlorvos reassessment – application Page 352 <strong>of</strong> 436
FactorExposure (μg/kg a.i. handled)Air blastEngineering controls Closed cab 42.0<strong>for</strong> air-blast applicator b Open cab 561.7[Closed cab is assumed to <strong>of</strong>fer 42/561.7 = 0.075 or 13.4x <strong>the</strong> protection factor vis-à-visOpen cabs <strong>for</strong> air-blast applicators.]Mixer/loadersEngineering controls Closed M/L 19.0<strong>for</strong> M/L (liquids) c Open M/L 51.0[Closed M/L is assumed to <strong>of</strong>fer 19/51 = 0.37 or 2.7x <strong>the</strong> protection factor vis-à-visOpen M/L <strong>for</strong> mixer/loaders.]a Ground-boom applicator wearing single layer <strong>of</strong> clothing and gloves (no hood/visor).b Air-blast applicator wearing single layer <strong>of</strong> clothing and gloves (no hood/visor).c Mixer/loader (liquids) wearing single layer <strong>of</strong> clothing and gloves.dFranklin, C. & Worgan, J.P. (2005) ―Occupational and Residential ExposureAssessment <strong>for</strong> Pesticides.‖ John Wiley and Sons; ISBN 0471489891, 9780471489894.[Abstract only]Dichlorvos reassessment – application Page 353 <strong>of</strong> 436
Appendix 2:Occupational Exposure Estimates & Risk Assessment with RTU gas cylinders &EC fogging <strong>of</strong> indoor spacesA) Worker/loader exposures during RTU gas cylinder changing:In <strong>the</strong> APVMA re-assessment (APVMA, 2008b) <strong>the</strong>y considered that operators mightbe exposed to dichlorvos when changing cylinders during gas fogging <strong>of</strong> glass- ormushroom houses (Scenarios 9 & 10) and enclosed (industrial) spaces (Scenarios 17, 18& 19).The APVMA estimated dermal exposure to be 0.001 mL/cylinder (equivalent to0.0014g dichlorvos; relative density, 1.425). Inhalation exposure could also result ifsome <strong>of</strong> <strong>the</strong> dichlorvos evaporated into <strong>the</strong> 1m 3 personal air space around <strong>the</strong> operator‘sbreathing zone. If 0.005ml <strong>of</strong> dichlorvos (wt. 7.1mg) was available <strong>for</strong> inhalation <strong>for</strong> 1minute, <strong>the</strong>n <strong>the</strong>y would inhale 0.12mg or 0.0017 mg/kg b.w. (70kg)In New Zealand, RTU gases are sold in 7 & 35L cylinders, at 50g a.i./L; and, use rates0.05 or 0.15g a.i./m 3 . For example, to cover 1.25ha at <strong>the</strong> equivalent <strong>of</strong> 0.05g a.i./m 3requires approximately 1.6kg (31.25L <strong>of</strong> product) or five 7L cylinders or one 35L (thisassumes a 2.5m building height).Dermal exposure from cylinder changingThe estimated absorbed dose from dermal exposure after 1 cylinder change would be,noting that gloves are assumed to be worn:And, five cylinder changes:Where:SE(d) = CR x WR x DA x PBWSE(d) = 1.4 x 1 x 0.30 x 0.1 = 0.042 = 0.0006 mg/kg b.w.7070SE(d) = 1.4 x 5 x 0.30 x 0.1 = 0.21= 0.003 mg/kg b.w.7070SE(d) = systemic exposure via <strong>the</strong> dermal routeCR = contamination rate [1.4 mg/cylinder change]WR = Work Rate [cylinder changes/day]DA = percent dermal absorption [30%]P = Penetration Factor <strong>for</strong> Clothing [gloves, 10%]BW = body weight [70kg]Dichlorvos reassessment – application Page 354 <strong>of</strong> 436
Inhalation exposure from cylinder changingThe estimated absorbed dose from inhalation exposure after 1 cylinder change wouldbe:SE(i) = CR x WR x IA x PBWAnd, five cylinder changes:Where:SE(i) = 0.12 x 1 x 1 x 1 =0.12= 0.0017 mg/kg b.w.70 70SE(i) = 0.12 x 5 x 1 x 1 =0.6= 0.0086 mg/kg b.w.70 70SE(i) = systemic exposure via <strong>the</strong> inhalation routeCR = contamination rate [0.12 mg/cylinder change]WR = Work Rate [cylinder changes/day, 1 and 5 respectively]IA = percent inhalation absorption [100%]P = Penetration Factor <strong>for</strong> RPE [none, 1; half-face respirator, 0.1 (90%protection); full-face, 0.02 (98%); air-hose, nil exposure (100%) (Thongsinthusaket al., 1993 in APVMA, 2008b)]BW = body weight [70kg]If RPE, a half-face respirator (P = 0.1), is worn <strong>the</strong>n <strong>the</strong> estimated absorbed dose frominhalation exposure after 1 cylinder change would be:SE(i) = 0.12 x 1 x 1 x 0.1 =0.012= 0.00017 mg/kg b.w.70 70If RPE, a half-face respirator (P = 0.1), is worn <strong>the</strong>n <strong>the</strong> estimated absorbed dose frominhalation exposure after 5 cylinder changes would be:SE(i) = 0.12 x 5 x 1 x 0.1 =0.06 = 0.00086 mg/kg b.w.70 70The equivalent result <strong>for</strong> 5 cylinder changes with a full-face respirator (P = 0.02) is:SE(i) = 0.12 x 5 x 1 x 0.02 = 0.012 = 0.00017 mg/kg b.w.70 70Dichlorvos reassessment – application Page 355 <strong>of</strong> 436
B)Operator exposures during manual application <strong>of</strong> RTU gas or EC fogging solutions:RTU gas containing 50g a.i./L is applied using a manual pressure gun in enclosedspaces <strong>of</strong> 375, 3750 and 12,500m 3 at use rates <strong>of</strong> 0.05g a.i./m 3 ; 18.75, 187.5 and 625ga.i. are required respectively <strong>for</strong> each space (Scenarios 9 & 10, and 17, 18 & 19). At <strong>the</strong>higher use rate <strong>of</strong> 0.15g a.i./m 3 ; 56.25, 562.5 and 1875g a.i. are required respectively <strong>for</strong>each space (Scenarios 17, 18 & 19).Exposures at <strong>the</strong> higher rate will be three times those at 0.05g a.i./m 3 .EC fogging solutions can also be applied at both use rates (Scenarios 22 & 23).Dermal exposures:The APVMA (2008b) used a Pesticide Handlers Exposure Database (PHED) exposuremodel <strong>for</strong> high pressure handwand application, modified to address <strong>the</strong> expectation that<strong>the</strong> efflux from a manual pressure gun would be significantly less diffuse and moredirectional, to estimate dermal exposures during enclosed space applications.Head/neck, exterior <strong>of</strong> clothing and hands were assumed to be contaminated with,respectively 0.018, 2.68 and 0.26 mg/kg active handled, 10% <strong>of</strong> <strong>the</strong> values from <strong>the</strong>PHED high pressure handwand model.For 375 m 3 – dermal exposure:= amount active handled [kg] x (head/neck + clothing + hands) [mg/kg]0.01875 kg a.i. x (0.018 + 2.68 + 0.26) = 0.0555 mg a.i./personThen applying <strong>the</strong> dermal absorption factor <strong>of</strong> 30%, and dividing by 70 kg b.w., <strong>the</strong>systemic dose will be:(0.0555 x 0.30) / 70 = 0.0167 / 70 = 0.0002 mg/kg b.w.If PPE is considered to mitigate exposures, APVMA used 20% penetration <strong>of</strong> overalls(Gold & Holsclaw, 1984; Original not sighted); 10% penetration <strong>of</strong> gloves(Thongsinthusak et al., 1993; Original not sighted); and, 5% penetration <strong>of</strong> full-bodychemical resistant clo<strong>the</strong>s (Thongsinthusak et al., 1993; Original not sighted):With overalls and gloves (protection factors applied to <strong>the</strong> body areas covered):[0.01875 x {0.018 + (2.68 x 0.2) + (0.26 x 0.1)} x 0.3] / 70 = (0.0109 x 0.30) / 70 =0.0033 / 70 = 0.00005 mg/kg b.w.With full-body chemical resistant clo<strong>the</strong>s and gloves:Dichlorvos reassessment – application Page 356 <strong>of</strong> 436
[0.01875 x {(0.018 x 0.05) + (2.68 x 0.05) + (0.26 x 0.1)} x 0.3] / 70 =(0.003 x 0.30) / 70 = 0.0009 / 70 = 0.00001 mg/kg b.w.For 3750 m 3 – dermal exposure:0.1875 kg a.i. x (0.018 + 2.68 + 0.26) = 0.5546 mg a.i./personThen applying <strong>the</strong> dermal absorption factor <strong>of</strong> 30%, and dividing by 70 kg b.w., <strong>the</strong>systemic dose will be:(0.5546 x 0.30) / 70 = 0.1664 / 70 = 0.0024 mg/kg b.w.With overalls and gloves (protection factors applied to <strong>the</strong> body areas covered):[0.1875 x {0.018 + (2.68 x 0.2) + (0.26 x 0.1)} x 0.3] / 70 = (0.1088 x 0.30) / 70 =0.0326 / 70 = 0.0005 mg/kg b.w.With full-body chemical resistant clo<strong>the</strong>s and gloves:[0.1875 x {(0.018 x 0.05) + (2.68 x 0.05) + (0.26 x 0.1)} x 0.3] / 70 =(0.0302 x 0.30) / 70 = 0.0091 / 70 = 0.0001 mg/kg b.w.For 12,500 m 3 – dermal exposure:0.625 kg a.i. x (0.018 + 2.68 + 0.26) = 1.8488 mg a.i./personThen applying <strong>the</strong> dermal absorption factor <strong>of</strong> 30%, and dividing by 70 kg b.w., <strong>the</strong>systemic dose will be:(1.8488 x 0.30) / 70 = 0.5546 / 70 = 0.0079 mg/kg b.w.With overalls and gloves (protection factors applied to <strong>the</strong> body areas covered):[0.625 x {(0.018 + (2.68 x 0.2) + (0.26 x 0.1)} x 0.3] / 70 = (0.3625 x 0.30) / 70 =0.1088 / 70 = 0.0016 mg/kg b.w.With full-body chemical resistant clo<strong>the</strong>s and gloves:Dichlorvos reassessment – application Page 357 <strong>of</strong> 436
[0.625 x {(0.018 x 0.05) + (2.68 x 0.05) + (0.26 x 0.1)} x 0.3] / 70 =(0.1006 x 0.30) / 70 = 0.0302 / 70 = 0.0004 mg/kg b.w.Inhalation exposures:For <strong>the</strong> estimation <strong>of</strong> inhalation exposures APVMA (2008b) noted that as long as <strong>the</strong>operator did not walk back through <strong>the</strong> efflux stream <strong>the</strong>n <strong>the</strong> highest airborneconcentration <strong>of</strong> dichlorvos should be <strong>the</strong> use rate, 50 mg/m 3 , with a TWA <strong>of</strong> 25 mg/m 3 .The APVMA estimated <strong>the</strong> duration <strong>of</strong> exposure on <strong>the</strong> application times from <strong>the</strong>manufacturer‘s specification <strong>for</strong> <strong>the</strong> manual pressure gun (70 sec/300 m 3 ; i.e. (375/300x 70) = 87.5 seconds, (3750/300 x 70) = 875 seconds and (12500/300 x 70) = 2917seconds <strong>for</strong> <strong>the</strong> New Zealand Scenarios) <strong>for</strong> larger industrial spaces. [These valueswere rounded to 1.5, 15 and 50 minutes, equivalent to 0.025, 0.25 and 0.83 hourrespectively <strong>for</strong> <strong>the</strong> model.] The operator‘s ventilation rate was taken as 1m 3 /hour <strong>for</strong>light activities (US EPA, 1996; Original not sighted).For 375 m 3 – inhalation exposure:= airborne concentration (TWA) [mg/m 3 ] x ventilation rate [m 3 /hr] x duration [hr]25 x 1 x 0.025 = 0.625 mg a.i./personThen accepting <strong>the</strong> inhalation absorption factor <strong>of</strong> 100%, and dividing by 70 kg b.w.,<strong>the</strong> systemic dose will be:(0.625 x 1.00) / 70 = 0.0089 mg/kg b.w.If RPE is considered to mitigate exposures, APVMA used 10% penetration <strong>of</strong> half-facerespirators; 2% penetration <strong>of</strong> full-face respirators; and, no penetration <strong>of</strong> air-hoserespirators or SCBA (Thongsinthusak et al., 1993; Original not sighted):With half-face (protection factor applied, 0.1):(25 x 1 x 0.025) / 70 = (0.625 x 0.10) / 70 = 0.0625 / 70 = 0.0009 mg/kg b.w.For 3750 m 3 – inhalation exposure:25 x 1 x 0.25 = 6.25 mg a.i./person.Then accepting <strong>the</strong> inhalation absorption factor <strong>of</strong> 100%, and dividing by 70 kg b.w.,<strong>the</strong> systemic dose will be:(6.25 x 1.00) / 70 = 0.0893 mg/kg b.wDichlorvos reassessment – application Page 358 <strong>of</strong> 436
With half-face respirator (protection factor applied, 0.1) <strong>the</strong> inhaled dose is 0.0089mg/kg b.w.With full-face respirator (protection factor applied, 0.02) <strong>the</strong> inhaled dose is 0.0018mg/kg b.w.For 12,500 m 3 – inhalation exposure:25 x 1 x 0.83 = 20.75 mg a.i./person.Then accepting <strong>the</strong> inhalation absorption factor <strong>of</strong> 100%, and dividing by 70 kg b.w.,<strong>the</strong> systemic dose will be:(20.75 x 1.00) / 70 = 0.2964 mg/kg b.wWith half-face respirator (protection factor applied, 0.1) <strong>the</strong> inhaled dose is 0.0296mg/kg b.w.With full-face respirator (protection factor applied, 0.02) <strong>the</strong> inhaled dose is 0.0059mg/kg b.w.The summation <strong>of</strong> <strong>the</strong>se exposure estimates and derivation <strong>of</strong> <strong>the</strong> RQ values ispresented in Table VI.Dichlorvos reassessment – application Page 359 <strong>of</strong> 436
Appendix 3:Occupational Exposure Estimates & Risk Assessment <strong>for</strong> Spray <strong>Application</strong>s intoEnclosed Spaces (Scenarios 24 & 25)Operator (Mixer/Loader/Applicator) during manual application:Spray is manually applied into enclosed spaces <strong>of</strong> 150, 1500 and 2500 m 2 (equivalentspaces: 375, 3750 and 12,500 m 3 ) at a use rates <strong>of</strong> 0.1 or 0.3g a.i./m 2 . The higherapplication rate <strong>of</strong> 0.30g a.i./m 2 would require: 45, 450 and 750g a.i. to be handled andapplied.Exposures at <strong>the</strong> higher use rate will be three times those at 0.1g a.i./m 2 .Dermal exposures:The APVMA considered <strong>the</strong> PHED model 35 (mixer/loader/applicators mixing liquid<strong>for</strong>mulations by open pour methods and applying <strong>the</strong> spraymix with high pressurehandwand) <strong>the</strong> most appropriate estimation method. The predicted dermal exposurerates on head, body and hands were respectively 1.155, 90.86 and 2.49 mg a.i./kgapplied. The spaces 150, 1500 and 2500 m 2 would require: 15, 150 and 250g a.i. to behandled and applied at 0.1g a.i./m 2 .For 150 m 2 – dermal exposure:= amount active handled [kg] x (head/neck + clothing + hands) [mg/kg]0.015 kg a.i. x (1.155 + 90.86 + 2.49) = 1.4176 mg a.i./personThen applying <strong>the</strong> dermal absorption factor <strong>of</strong> 30%, and dividing by 70 kg b.w., <strong>the</strong>systemic dose will be:(1.4176 x 0.30) / 70 = 0.4253 / 70 = 0.0061 mg/kg b.w.If PPE is considered to mitigate exposures, APVMA used 20% penetration <strong>of</strong> overalls(Gold & Holsclaw, 1984; Original not sighted); 10% penetration <strong>of</strong> gloves(Thongsinthusak et al., 1993; Original not sighted); and, 5% penetration <strong>of</strong> full-bodychemical resistant clo<strong>the</strong>s (Thongsinthusak et al., 1993; Original not sighted):With overalls and gloves (protection factors applied to <strong>the</strong> body areas covered):[0.015 x {1.155 + (90.86 x 0.2) + (2.49 x 0.1)} x 0.3] / 70 = (0.2936 x 0.3) / 70 =0.0881 / 70 = 0.0013 mg/kg b.w.Dichlorvos reassessment – application Page 360 <strong>of</strong> 436
With full-body chemical resistant clo<strong>the</strong>s and gloves:[0.015 x {(1.155 x 0.05) + (90.86 x 0.05) + (2.49 x 0.1)} x 0.3] / 70 =(0.0728 x 0.3) / 70 = 0.0218 / 70 = 0.0003 mg/kg b.w.For 1500 m 2 – dermal exposure:With full-body chemical resistant clo<strong>the</strong>s and gloves:[0.15 x {(1.155 x 0.05) + (90.86 x 0.05) + (2.49 x 0.1)} x 0.3] / 70 = (0.7275 x 0.3) / 70= 0.2182 / 70 = 0.0031 mg/kg b.w.For 2500 m 2 – dermal exposure:With full-body chemical resistant clo<strong>the</strong>s and gloves:[0.25 x {(1.155 x 0.05) + (90.86 x 0.05) + (2.49 x 0.1)} x 0.3] / 70 = (1.2125 x 0.3) / 70= 0.3638 / 70 = 0.0078 mg/kg b.w.At <strong>the</strong> higher use rate <strong>of</strong> 0.3g a.i./m 2 requiring 45, 450 and 750g a.i. to be handled andapplied.For 150 m 2 – dermal exposure: With full-body chemical resistant clo<strong>the</strong>s and gloves:[0.045 x {(1.155 x 0.05) + (90.86 x 0.05) + (2.49 x 0.1)} x 0.3] / 70 =(0.2182 x 0.3) / 70 = 0.0655 / 70 = 0.0009 mg/kg b.w.Inhalation exposures:For inhalation exposures from using high pressure handwand equipment indoors,APVMA modified <strong>the</strong> most relevant PHED model to account <strong>for</strong> <strong>the</strong> high volatility <strong>of</strong>dichlorvos and estimated an inhalation exposure rate <strong>of</strong> 13.2 mg a.i./kg applied [50 foldincrease to account <strong>for</strong> <strong>the</strong> higher volatility, but also <strong>the</strong> slower volatilisation and greaterdroplet precipitation <strong>of</strong> an aerosol compared to a CO 2 pressure gun efflux].For 150 m 2 – inhalation exposure:= amount active handled [kg] x inhalation exposure [mg/kg handled]0.015 x 13.2 = 0.198 mg a.i./personDichlorvos reassessment – application Page 361 <strong>of</strong> 436
Then accepting <strong>the</strong> inhalation absorption factor <strong>of</strong> 100%, and dividing by 70 kg b.w.,<strong>the</strong> systemic dose will be:(0.198 x 1.00) / 70 = 0.0028 mg/kg b.w.If RPE is considered to mitigate exposures, APVMA used 10% penetration <strong>of</strong> half-facerespirators; 2% penetration <strong>of</strong> full-face respirators; and, no penetration <strong>of</strong> air-hoserespirators or SCBA (Thongsinthusak et al., 1993; Original not sighted):With half-face (protection factor applied, 0.10):(0.015 x 13.2 x 0.10) / 70 = 0.0198 / 70 = 0.0003 mg/kg b.w.With full-face (protection factor applied, 0.02):(0.015 x 13.2 x 0.02) / 70 = 0.0040 / 70 = 0.00006 mg/kg b.w.For 1500 m 2 – inhalation exposure (70kg b.w.):With full-face (protection factor applied, 0.02):(0.15 x 13.2 x 0.02) / 70 = 0.0396 / 70 = 0.0006 mg/kg b.w.For 2500 m 2 – inhalation exposure (70kg b.w.):With full-face (protection factor applied, 0.02):(0.25 x 13.2 x 0.02) / 70 = 0.066 / 70 = 0.0009 mg/kg b.w.The summation <strong>of</strong> <strong>the</strong>se exposure estimates and derivation <strong>of</strong> <strong>the</strong> RQ values ispresented in Table VIII.Dichlorvos reassessment – application Page 362 <strong>of</strong> 436
Appendix 4:Occupational Exposure Estimates & Risk Assessment <strong>for</strong> Spray <strong>Application</strong>s intoPublic Spaces (Scenario 30)Spray is manually applied by fogging over public spaces <strong>of</strong> up to 1 hectare at a use rate<strong>of</strong> 0.1g a.i./m 2 (10ml product/ 2L spraymix/ 100m 2 ). This application rate and arearequires 1000g a.i. to be handled and applied.Mixer/Loader exposures:The APVMA used <strong>the</strong> PHED model 3 (mixer/loader mixing liquid <strong>for</strong>mulations byopen pour methods) as <strong>the</strong> most appropriate estimation method <strong>for</strong> predicting dermaland inhalation exposures. The predicted dermal exposure rates on head, body and handswere respectively 0.0116, 0.6622 and 6.248 mg a.i./kg handled.Dermal exposures:= amount active handled [kg] x (head/neck + clothing + hands) [mg/kg]1 kg a.i. x (0.0116 + 0.6622 + 6.248) = 6.9216 mg a.i./personThen applying <strong>the</strong> dermal absorption factor <strong>of</strong> 30%, and dividing by 70 kg b.w., <strong>the</strong>systemic dose will be:(6.9216 x 0.30) / 70 = 2.0765 / 70 = 0.0297 mg/kg b.w.If PPE is considered to mitigate exposures, APVMA used 20% penetration <strong>of</strong> overalls(Gold & Holsclaw, 1984; Original not sighted); 10% penetration <strong>of</strong> gloves(Thongsinthusak et al., 1993; Original not sighted); and, 5% penetration <strong>of</strong> full-bodychemical resistant clo<strong>the</strong>s (Thongsinthusak et al., 1993; Original not sighted):With overalls and gloves (protection factors applied to <strong>the</strong> body areas covered):[1 x {0.0116 + (0.6622 x 0.2) + (6.248 x 0.1)} x 0.3] / 70 = (0.7688 x 0.3) / 70 =0.2307 / 70 = 0.0033 mg/kg b.w.With full-body chemical resistant clo<strong>the</strong>s and gloves:[1 x {(0.0116 x 0.05) + (0.6622 x 0.05) + (6.248 x 0.1)} x 0.3] / 70 = (0.6585 x 0.3) / 70= 0.1976 / 70 = 0.0028 mg/kg b.w.Inhalation exposures:Dichlorvos reassessment – application Page 363 <strong>of</strong> 436
The APVMA considered that <strong>the</strong> predicted rate <strong>of</strong> inhalation exposure from PHEDmodel 3 would be significantly <strong>under</strong>estimated <strong>for</strong> dichlorvos due to its high volatility.Utilising data from one study (Gold & Holcslaw, 1984; Original not sighted), <strong>the</strong>APVMA increased <strong>the</strong> predicted rate <strong>of</strong> inhalation exposure by 50-fold to give 0.132mg a.i./kg handled.= amount active handled [kg] x inhalation exposure [mg/kg handled]1 x 0.132 = 0.132 mg a.i./personThen accepting <strong>the</strong> inhalation absorption factor <strong>of</strong> 100%, and dividing by 70 kg b.w.,<strong>the</strong> systemic dose will be:(0.132 x 1.00) / 70 = 0.0019 mg/kg b.w.If RPE is considered to mitigate exposures, APVMA used 10% penetration <strong>of</strong> half-facerespirators; 2% penetration <strong>of</strong> full-face respirators; and, no penetration <strong>of</strong> air-hoserespirators or SCBA (Thongsinthusak et al., 1993; Original not sighted):With half-face (protection factor applied):((1 x 0.132) x 0.10) / 70 = 0.0132 / 70 = 0.0002 mg/kg b.w.With full-face (protection factor applied):((1 x 0.132 x 0.02) / 70 = 0.0026 / 70 = 0.00004 mg/kg b.w.Applicator exposures:The APVMA used <strong>the</strong> data-based PHED model 19 to predict exposures duringapplication. The predicted dermal exposure rates on head, body and hands wererespectively 0.184, 26.8 and 2.55 mg a.i./kg handled, while <strong>the</strong> predicted inhalation.Dermal exposures:= amount active handled [kg] x (head/neck + clothing + hands) [mg/kg]1 kg a.i. x (0.184 + 26.8 + 2.55) = 29.534 mg a.i./personThen applying <strong>the</strong> dermal absorption factor <strong>of</strong> 30%, and dividing by 70 kg b.w., <strong>the</strong>systemic dose will be:(29.534 x 0.30) / 70 = 8.8602 / 70 = 0.1266 mg/kg b.w.If PPE is considered to mitigate exposures, APVMA used 20% penetration <strong>of</strong> overalls(Gold & Holsclaw, 1984; Original not sighted); 10% penetration <strong>of</strong> gloves(Thongsinthusak et al., 1993; Original not sighted); and, 5% penetration <strong>of</strong> full-bodychemical resistant clo<strong>the</strong>s (Thongsinthusak et al., 1993; Original not sighted):Dichlorvos reassessment – application Page 364 <strong>of</strong> 436
With overalls and gloves (protection factors applied to <strong>the</strong> body areas covered):[1 x {0.184 + (26.8 x 0.2) + (2.55 x 0.1)} x 0.3] / 70 = (5.799 x 0.3) / 70 =1.7397 / 70 = 0.0249 mg/kg b.w.With full-body chemical resistant clo<strong>the</strong>s and gloves:[1 x {(0.184 x 0.05) + (26.8 x 0.05) + (2.55 x 0.1)} x 0.3] / 70 = (1.6042 x 0.3) / 70 =0.4813 / 70 = 0.0069 mg/kg b.w.Inhalation exposures:PHED model 19 predicted <strong>the</strong> inhalation exposure rate was 0.174 mg a.i./kg handled.= amount active handled [kg] x inhalation exposure [mg/kg handled]1 x 0.174 = 0.174 mg a.i./personThen accepting <strong>the</strong> inhalation absorption factor <strong>of</strong> 100%, and dividing by 70 kg b.w.,<strong>the</strong> systemic dose will be:(0.174 x 1.00) / 70 = 0.0025 mg/kg b.w.If RPE is considered to mitigate exposures, APVMA used 10% penetration <strong>of</strong> half-facerespirators; 2% penetration <strong>of</strong> full-face respirators; and, no penetration <strong>of</strong> air-hoserespirators or SCBA (Thongsinthusak et al., 1993; Original not sighted):With half-face (protection factor applied):((1 x 0.174) x 0.10) / 70 = 0.0174 / 70 = 0.0003 mg/kg b.w.With full-face (protection factor applied):((1 x 0.174) x 0.02) / 70 = 0.0035 / 70 = 0.00005 mg/kg b.w.Dichlorvos reassessment – application Page 365 <strong>of</strong> 436
Appendix 5Re-entry Worker Exposure Estimate and Risk Assessment – Out-door Crops(Example calculations <strong>for</strong> Table XII)Scenarios 1 & 2, 3c & 4c: Berries (0.8kg/ha with 1 or 2 applications per year)Re-entry by a worker <strong>for</strong> picking: dermal exposure.Assuming an application <strong>of</strong> 800g dichlorvos/ha.A working day <strong>of</strong> 8 hours is assumed.For <strong>the</strong> transfer <strong>of</strong> residues from foliage to <strong>the</strong> clo<strong>the</strong>s or skin <strong>of</strong> a worker, a TC value <strong>of</strong>3000 cm 2 /hr is used (UK CRD, 2008a).A DFR value <strong>of</strong> 0.5 μg/cm 2 per kg a.s./ha applied is used (based on Casida et al., 1962in APVMA, 2008b) (See paragraphs 5.9 & 5.10).Predicted exposure <strong>for</strong> this scenario is thusD = DFR x TC x DA x WR x AR x P / BWWhere:D = Dermal Exposure [μg a.s./person*d]DFR = Dislodgeable Foliar Residue per kg a.s./ha = 0.5 μg a.s./cm² per kga.s./haTC = Transfer Coefficient [cm²/person/h] = 3000 [cm²/person/h]DA = percentage dermal absorption (30%), expressed as a fractionWR = Work Rate [8 hours/day]AR = <strong>Application</strong> Rate [0.8 kg a.s./ha]P = Penetration Factor <strong>for</strong> Clothing [= 1] which assumes one layer <strong>of</strong> ordinaryclothing is taken into accountBW = bodyweight (70 kg)Dermal Exposure (D) is 41 μg a.s./kg b.w./day.D = 0.5 x 3000 x 0.3 x 8 x 0.8 x 1 = 2880 / 7070With PPE:The German BBA Model <strong>for</strong> re-entry tasks assumes a Penetration Factor (P) <strong>for</strong> PPE as0.05 (i.e. 95% protection, given by hood/visor + overalls over long-sleeved shirt andlong-legged trousers + boots + gloves).Applying <strong>the</strong>se figures to <strong>the</strong> Penetration Factor <strong>for</strong> Clothing (P) in <strong>the</strong> above equationgives <strong>the</strong> previous D x 0.05.Dichlorvos reassessment – application Page 366 <strong>of</strong> 436
The Dermal Exposure (D) is 2.06 μg a.s./kg b.w./day.Re-entry by a worker <strong>for</strong> picking: inhalation exposure.Using <strong>the</strong> data from Casida et al. (1962), 20 minutes after application to <strong>the</strong> leafsurfaces <strong>of</strong> maize, cotton and peas about 50% was volatilised, while 5% remains on <strong>the</strong>leaf surfaces and 45% absorbed by <strong>the</strong> plant (in APVMA, 2008b).It is assumed <strong>the</strong>re<strong>for</strong>e that only 50% <strong>of</strong> <strong>the</strong> application rate is available <strong>for</strong> possibleinhalation:Inhalation Exposure (I) = mg a.s./hr inhaled x WR / BWmg a.s./hr inhaled = kg/a.s./ha applied x Task Specific FactorWhere:indicative Task Specific Factor = 0.01 (See paragraph 5.20);WR = Work Rate (8 hours/day)AR = <strong>Application</strong> Rate (50% <strong>of</strong> 0.8 kg a.s./ha)BW = bodyweight (70 kg)I = ((0.5 x 0.8 x 0.01) x 8) / 70 = 0.032 / 70 = 0.00046 mg/kg b.w./dayInhalation Exposure (I) is 0.00046 mg a.s./kg b.w./day or 0.46 μg a.s./kg b.w./day.With RPE:The APVMA (2008b) use <strong>the</strong> following protective factors <strong>for</strong> various RPE:Half-face respirator 0.1Full-face 0.02Air-hosenil inhalation exposureWith a half-face respirator: I = 0.46 x 0.1 = 0.046 μg a.s./kg b.w./day;full-face:I = 0.46 x 0.02 = 0.0092 μg a.s./kg b.w./day;Dichlorvos reassessment – application Page 367 <strong>of</strong> 436
Appendix 6Resident Exposures to Dichlorvos, and Risk Assessment:Exposure through contact with spray drift contaminated surfaces―It is possible that spray drift fallout from applications may be deposited in privategardens adjacent to treated areas, and individuals in such locations may becomeexposed through contact with such deposits. A possible scenario that illustrates asignificant opportunity <strong>for</strong> exposure would be children playing in a garden which hasbeen subject to spray drift fallout. It is possible to estimate such exposures using spraydrift fallout values used <strong>for</strong> aquatic risk assessment purposes (Rautmann et al., 2001)and <strong>the</strong> approach used by <strong>the</strong> United States Environmental Protection Agency toestimate residential exposure from contact with treated lawns (USA EPA 1998 / 1999 /2001). The exposure assessment reported … considers <strong>the</strong> scenario <strong>of</strong> a small childplaying on a lawn …For products which may be applied to crops on more than one occasion <strong>the</strong> <strong>the</strong>oreticalworse case is to consider children‘s exposure from <strong>the</strong> maximum total dose which maybe applied, i.e. to assume that <strong>the</strong>re is no dissipation in foliar residues betweensuccessive treatments. This approach may be refined where data are available to refine<strong>the</strong> estimated residues.‖ [quoted from UK CRD 2008b]The small child playing on a lawn leads to four potential exposures: dermal (skincontact); hand-to-mouth (sucking contacted fingers and thumbs); object-to-mouth(sucking contaminated objects, toys etc.); and, soil/grass ingestion by <strong>the</strong> child.Field crop (boom) sprayersScenarios (1-4): applications at 0.8 kg a.i./ha1) Children‘s dermal exposureSystemic exposures via <strong>the</strong> dermal route were calculated using <strong>the</strong> above drift falloutvalues and <strong>the</strong> following equation <strong>for</strong> boom sprayers:SE(d) = AR x DF x TTR x TC x H x DABWSE(d) = 8 x 0.01 x (0.05 x 0.05) x 5200 x 2 x 0.30 = 0.624 / 15 = 0.0416 μg/kg b.w.15Where:SE(d) = systemic exposure via <strong>the</strong> dermal routeAR = field application rate, 0.8 kg/ha = 8 μg/cm 2DF = drift fallout value, i.e. assumed average <strong>of</strong> 1% from boom sprayerapplicationsDichlorvos reassessment – application Page 368 <strong>of</strong> 436
TTR = turf transferable residues – <strong>the</strong> EPA default value <strong>of</strong> 5% was used in <strong>the</strong>estimate (US EPA, CARES Manual, 2002) modified by 5% from <strong>the</strong> Casida et al.data) (see para 6.10)TC = transfer coefficient – <strong>the</strong> standard EPA value <strong>of</strong> 5200 cm 2 /h was used <strong>for</strong> <strong>the</strong>estimateH = exposure duration <strong>for</strong> a typical day (hours) – this has been assumed to be 2hours which matches <strong>the</strong> 75th percentile <strong>for</strong> toddlers playing on grass in <strong>the</strong> EPAExposure Factors HandbookDA = percent dermal absorption (30%)BW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs2) Children‘s hand-to-mouth exposureHand-to-mouth exposures were calculated using turf transferable residue levels using<strong>the</strong> following equation <strong>for</strong> boom sprayers:SE(h) = AR x DF x TTR x SE x SA x Freq x HBWSE(h) = 8 x 0.01 x (0.05 x 0.05) x 0.50 x 20 x 20 x 2 = 0.08 / 15 = 0.0053 μg/kg b.w.15Where:SE(h) = systemic exposure via <strong>the</strong> hand-to-mouth routeAR = field application rate, 0.8 kg/ha = 8 μg/cm 2DF = drift fallout value, i.e. assumed average <strong>of</strong> 1% from boom sprayerapplicationsTTR = turf transferable residues – <strong>the</strong> EPA default value <strong>of</strong> 5% derived fromtransferability studies with wet hands was used in <strong>the</strong> estimate modified by 5%from <strong>the</strong> Casida et al. data)SE = saliva extraction factor – <strong>the</strong> default value <strong>of</strong> 50% was usedSA = surface area <strong>of</strong> <strong>the</strong> hands – <strong>the</strong> assumption used here is that 20 cm 2 <strong>of</strong> skinarea is contacted each time a child puts a hand in his or her mouth (this isequivalent to <strong>the</strong> palmer surface <strong>of</strong> three figures and is also related to <strong>the</strong> nextparameter)Freq = frequency <strong>of</strong> hand to mouth events/hour – <strong>for</strong> short term exposures <strong>the</strong>value <strong>of</strong> 20 events/hours is used, this is <strong>the</strong> 90th percentile <strong>of</strong> observations thatranges from 0 to 70 events/hourH = exposure duration (hours) – this has been assumed to be 2 hours whichmatches <strong>the</strong> 75th percentile <strong>for</strong> toddlers playing on grass in <strong>the</strong> EPA ExposureFactors HandbookBW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs3) Children‘s object-to-mouth exposureDichlorvos reassessment – application Page 369 <strong>of</strong> 436
Object to mouth exposures were calculated using turf transferable residue levels using<strong>the</strong> following equation <strong>for</strong> boom sprayers:Where:SE(o) = AR x DF x TTR x IgRBWSE(o) = 8 x 0.01 x (0.20 x 0.05) x 25 = 0.02 / 15 = 0.0013 μg/kg b.w.15SE(o) = systemic exposure via mouthing activityAR = field application rate, 0.8 kg/ha = 8 μg/cm 2DF = drift fallout value, i.e. assumed average <strong>of</strong> 1% from boom sprayerapplicationsTTR = turf transferable residues <strong>the</strong> default value <strong>of</strong> 20% transferability fromobject to mouth assessments was used modified by 5% from <strong>the</strong> Casida et al.data)IgR = ingestion rate <strong>for</strong> mouthing grass/day – this was assumed to be equivalentto 25cm 2 <strong>of</strong> grass/dayBW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs.4) Children‘s incidental ingestion <strong>of</strong> soil (US EPA, 2006b)The approach used to calculate doses that are attributable to soil ingestion is:Average Daily Oral Dose = (AR x DF) x F x IgR x SDF / BWADOD = (0.008 x (0.01 x 0.05)) x 1.0 x 100 x (6.7 x 10 -4 ) x 1000 =150.00027 / 15 = 0.00002 μg/kg b.w.Where:ADOD = oral dose on day <strong>of</strong> application (mg/kg b.w./day)AR = application rate (0.008 mg/cm 2 ); DF = 0.01 [Note: this value has beenmodified by <strong>the</strong> DF values used in <strong>the</strong> first 3 equations to reflect <strong>the</strong>se spray driftsituations, and not direct turf applications.]F = fraction <strong>of</strong> residue retained on uppermost 1 cm <strong>of</strong> soil (%) (note: this is anadjustment from surface area to volume) modified by 5% from <strong>the</strong> Casida et al.data)SDF = soil density factor -- volume <strong>of</strong> soil (cm 3 ) per microgram <strong>of</strong> soil;IgR = ingestion rate <strong>of</strong> soil (mg/day)BW = body weight (kg)Assumptions:Dichlorvos reassessment – application Page 370 <strong>of</strong> 436
F = fraction <strong>of</strong> residue retained on uppermost 1 cm <strong>of</strong> soil is 100 percent based onsoil incorporation into top 1 cm <strong>of</strong> soil after application (1.0/cm)SDF = soil density factor -- volume <strong>of</strong> soil (cm 3 ) per gram <strong>of</strong> soil; to weight 6.7 x10 -4 cm 3 /mg soil)IgR - ingestion rate <strong>of</strong> soil is 100 mg/dayBW - body weight <strong>of</strong> a toddler is 15 kg5) Children‘s total exposure from applications at 0.8 kg a.i./ha:Children‘s total exposure was estimated as <strong>the</strong> sum <strong>of</strong> <strong>the</strong> dermal, hand-to-mouth,object to mouth exposures and soil ingestion, which was 0.0482 μg/kg b.w./day. Thistotal exposure represents an RQ <strong>of</strong> 0.03 (in comparison to <strong>the</strong> AOEL <strong>of</strong> 1.4 μg/kgb.w./day).Broadcast air assisted – orchard applicationsScenarios (5 & 6): applications at 2.052 kg a.i./haFor Scenarios (5 & 6), <strong>the</strong> application rate (AR) is 20.52 µg/cm 2 , which is a factor <strong>of</strong>2.565 greater than <strong>for</strong> Scenarios (1-4). In addition <strong>the</strong> DF increases to 10% from 1%,giving a total increase <strong>of</strong> 25.65 fold.There<strong>for</strong>e if <strong>the</strong> above calculations are repeated <strong>for</strong> <strong>the</strong>se Scenarios, <strong>the</strong> final outcome isthat <strong>the</strong> child‘s total estimated exposure is 1.2368 µg/kg b.w./day, and <strong>the</strong> RQ = 0.9 (incomparison to <strong>the</strong> AOEL <strong>of</strong> 1.4 μg/kg b.w./day).Scenarios (7 & 8): applications at 1.026 kg a.i./haFor Scenarios (7 & 8), <strong>the</strong> application rate (AR) is 10.26 µg/cm 2 , which is a factor <strong>of</strong>1.2825 greater than <strong>for</strong> Scenarios (1-4). In addition <strong>the</strong> DF increases to 10% from 1%,giving a total increase <strong>of</strong> 12.825 fold.There<strong>for</strong>e if <strong>the</strong> above calculations are repeated <strong>for</strong> <strong>the</strong>se Scenarios, <strong>the</strong> final outcome isthat <strong>the</strong> child‘s total estimated exposure is 0.6184 µg/kg b.w./day, and <strong>the</strong> RQ = 0.4 (incomparison to <strong>the</strong> AOEL <strong>of</strong> 1.4 μg/kg b.w./day).Dichlorvos reassessment – application Page 371 <strong>of</strong> 436
Domestic Indoor Surface <strong>Application</strong>sScenarios (26 & 27): applications at 2.5 kg a.i./ha (A 600mL can contains 1.86g a.i.that covers 7.44m 2 at <strong>the</strong> recommended rate, 0.25g a.i./m 2 )1) Children‘s dermal exposureSystemic exposures via <strong>the</strong> dermal route were calculated using a 100% drift falloutvalue (assumes spray stays to <strong>the</strong> surface where it is applied and <strong>the</strong>re is no dissipationbe<strong>for</strong>e or during exposure) and <strong>the</strong> following equation:Where:SE(d) = AR x DF x TTR x TC x H x DABWSE(d) = 25 x 1 x 0.05 x 6000 x 8 x 0.30 = 1200 μg/kg b.w.15SE(d) = systemic exposure via <strong>the</strong> dermal route;AR = field application rate, 2.5 kg/ha = 25 μg/cm 2 ;DF = drift fallout value, i.e. assumed at 100%;TTR = transferable residues – <strong>the</strong> EPA default value <strong>of</strong> 5% was used in <strong>the</strong>estimate (US EPA, CARES Manual, 2002);TC = transfer coefficient – <strong>the</strong> standard EPA value <strong>of</strong> 6000 cm 2 /h was used <strong>for</strong> <strong>the</strong>estimate;H = exposure duration <strong>for</strong> a typical day (hours) – this has been assumed to be 8hours which matches <strong>the</strong> average time in any one indoor space;DA = percent dermal absorption (30%);BW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs.2) Children‘s hand-to-mouth exposureHand-to-mouth exposures were calculated using transferable residue levels using <strong>the</strong>following equation:Where:SE(h) = AR x DF x TTR x SE x SA x Freq x HBWSE(h) = 25 x 1 x 0.05 x 0.50 x 20 x 20 x 2 = 33.33 μg/kg b.w.15SE(h) = systemic exposure via <strong>the</strong> hand-to-mouth route;AR = field application rate, 2.5 kg/ha = 25 μg/cm 2 ;DF = drift fallout value, i.e. assumed 100%;Dichlorvos reassessment – application Page 372 <strong>of</strong> 436
TTR = transferable residues – <strong>the</strong> EPA default value <strong>of</strong> 5% derived fromtransferability studies with wet hands was used in <strong>the</strong> estimate;SE = saliva extraction factor – <strong>the</strong> default value <strong>of</strong> 50% was used;SA = surface area <strong>of</strong> <strong>the</strong> hands – <strong>the</strong> assumption used here is that 20 cm 2 <strong>of</strong> skinarea is contacted each time a child puts a hand in his or her mouth (this isequivalent to <strong>the</strong> palmer surface <strong>of</strong> three figures and is also related to <strong>the</strong> nextparameter);Freq = frequency <strong>of</strong> hand to mouth events/hour – <strong>for</strong> short term exposures <strong>the</strong>value <strong>of</strong> 20 events/hours is used, this is <strong>the</strong> 90th percentile <strong>of</strong> observations thatranges from 0 to 70 events/hour;H = exposure duration (hours) – this has been assumed to be 2 hours whichmatches <strong>the</strong> 75th percentile <strong>for</strong> toddlers playing on grass in <strong>the</strong> EPA ExposureFactors Handbook;BW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs.3) Children‘s object-to-mouth exposureObject to mouth exposures were calculated using transferable residue levels using <strong>the</strong>following equation:Where:SE(o) = AR x DF x TTR x IgRBWSE(o) = 25 x 1 x 0.20 x 25 = 8.33 μg/kg b.w.15SE(o) = systemic exposure via mouthing activity;AR = field application rate, 2.5 kg/ha = 25 μg/cm 2 ;DF = drift fallout value, i.e. assumed 100%;TTR = transferable residues <strong>the</strong> default value (<strong>for</strong> turf) <strong>of</strong> 20% transferabilityfrom object to mouth assessments was used;IgR = ingestion rate <strong>for</strong> mouthing grass/day – this was assumed to be equivalentto 25cm 2 <strong>of</strong> grass/day;BW = body weight - 15kg which is <strong>the</strong> average <strong>of</strong> UK 1995-7 Health Surveys <strong>for</strong>England values <strong>for</strong> males and females <strong>of</strong> 2 and 3 yrs.4) Children‘s incidental ingestion <strong>of</strong> soil (US EPA, 2006b)This was not seen to be relevant <strong>for</strong> <strong>the</strong> indoor uses.5) Children‘s total exposure from applications at 2.5 kg a.i./ha:Dichlorvos reassessment – application Page 373 <strong>of</strong> 436
Children‘s total exposure was estimated as <strong>the</strong> sum <strong>of</strong> <strong>the</strong> dermal, hand-to-mouth andobject to mouth exposures, which was 1.2417 mg/kg b.w./day. This total exposurerepresents an RQ <strong>of</strong> 887 (in comparison to <strong>the</strong> AOEL <strong>of</strong> 0.0014 mg/kg b.w./day).Domestic Outdoor Surface <strong>Application</strong>sScenarios (28 & 29): are also applications at 2.5 kg a.i./ha, but contaminated soilingestion (due to overspray or drift) is also possible.So, in addition to <strong>the</strong> estimated exposure <strong>of</strong> children above:4) Children‘s incidental ingestion <strong>of</strong> soil (US EPA, 2006b)The approach used to calculate doses that are attributable to soil ingestion is:Average Daily Oral Dose = (AR x DF) x F x IgR x SDF / BWADOD = (0.025 x 1) x 1.0 x 100 x (6.7 x 10 -4 ) x 1000 = 0.1117 μg/kg b.w.15Where:ADOD = oral dose on day <strong>of</strong> application (mg/kg b.w./day)AR = application rate (0.025 mg/cm 2 ); DF = 1;F = fraction <strong>of</strong> residue retained on uppermost 1 cm <strong>of</strong> soil (%) (note: this is anadjustment from surface area to volume);SDF = soil density factor -- volume <strong>of</strong> soil (cm 3 ) per microgram <strong>of</strong> soil;IgR = ingestion rate <strong>of</strong> soil (mg/day);BW = body weight (kg).Assumptions:F = fraction <strong>of</strong> residue retained on uppermost 1 cm <strong>of</strong> soil is 100 percent based onsoil incorporation into top 1 cm <strong>of</strong> soil after application (1.0/cm);SDF = soil density factor -- volume <strong>of</strong> soil (cm 3 ) per gram <strong>of</strong> soil; to weight 6.7 x10 -4 cm 3 /mg soil);IgR - ingestion rate <strong>of</strong> soil is 100 mg/day;BW - body weight <strong>of</strong> a toddler is 15 kg.5) Children‘s total exposure from applications at 2.5 kg a.i./ha:Children‘s total exposure was estimated as <strong>the</strong> sum <strong>of</strong> <strong>the</strong> dermal, hand-to-mouth,object to mouth exposures and soil ingestion, which was 1.2428 mg/kg b.w./day. Thistotal exposure represents an RQ <strong>of</strong> 888 (in comparison to <strong>the</strong> AOEL <strong>of</strong> 0.0014 mg/kgb.w./day).Dichlorvos reassessment – application Page 374 <strong>of</strong> 436
Public Space <strong>Application</strong>sScenario (30): applications at 1 kg a.i./ha, with contaminated soil ingestion (due tooverspray or drift) is also possible.1) Children‘s dermal exposure (UK CRD)SE(d) = 10 x 1 x 0.05 x 5200 x 2 x 0.30 = 104 μg/kg b.w.152) Children‘s hand-to-mouth exposure (UK CRD)SE(h) = 10 x 1 x 0.05 x 0.50 x 20 x 20 x 2 = 13.33 μg/kg b.w.153) Children‘s object-to-mouth exposure (UK CRD)SE(o) = 10 x 1 x 0.20 x 25 = 3.33 μg/kg b.w.154) Children‘s incidental ingestion <strong>of</strong> soil (US EPA, 2006b)ADOD = (0.010 x 1) x 1.0 x 100 x (6.7 x 10 -4 ) x 1000 = 0.0447 μg/kg b.w.155) Children‘s total exposure from applications at 1.0 kg a.i./ha:Children‘s total exposure was estimated as <strong>the</strong> sum <strong>of</strong> <strong>the</strong> dermal, hand-to-mouth,object to mouth exposures and soil ingestion, which was 0.1207 mg/kg b.w./day. Thistotal exposure represents an RQ <strong>of</strong> 86 (in comparison to <strong>the</strong> AOEL <strong>of</strong> 0.0014 mg/kgb.w./day).Dichlorvos reassessment – application Page 375 <strong>of</strong> 436
Last PageDichlorvos reassessment – application Page 376 <strong>of</strong> 436
ERMA New Zealand‟s comment on <strong>the</strong> Occupational Exposure report.Given <strong>the</strong> extremely complex nature <strong>of</strong> <strong>the</strong> overall use pattern <strong>of</strong> dichlorvos, in order toprovide a simple overview <strong>of</strong> <strong>the</strong> human health exposure results ERMA New Zealand hasproduced a plot <strong>of</strong> risk quotients <strong>for</strong> mixing, loading and application lifecycle stages <strong>for</strong> each<strong>of</strong> <strong>the</strong> individual Use Scenarios.Each Use Scenario comprises <strong>of</strong> a range <strong>of</strong> variables, including application rates, differinglevels <strong>of</strong> PPE, etc. Each combination <strong>of</strong> variables has been assigned a ‗Chart Number‘,which must be cross referenced with <strong>the</strong> key provided after <strong>the</strong> summary plot in order todetermine <strong>the</strong> corresponding Use Scenario.The chart is drawn on a logarithmic scale. The x-axis intercepts <strong>the</strong> y-azis at an RQ value <strong>of</strong>1, which indicates that values below <strong>the</strong> x axis are viewed as negligible risk. RQs above <strong>the</strong>x-axis (i.e. RQ > 1) relates to a non-negligible risk.Dichlorvos reassessment – application Page 377 <strong>of</strong> 436
Risk QuotientDichlorvos Mixing Loading and <strong>Application</strong> Scenarios10001001011 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54Chart Number0.1Dichlorvos reassessment – application Page 378 <strong>of</strong> 436
Enclosed SpaceAgricultural UseOutdoor Agricultural UseAll assessments <strong>for</strong> this scenariohave unacceptable RQsSome but not all assessments <strong>for</strong> thisscenario have unacceptable RQsAll assessments <strong>for</strong> thisScenario have acceptable RQsReport Scenario Groupand NumberScenarios 1-4boom sprayer wi<strong>the</strong>ngineering controlsScenarios 1-4boom sprayer withoutengineering controlsScenarios 5 & 6Broadcast air assistedsprayer wi<strong>the</strong>ngineering controlsScenarios 5 & 6Broadcast air assistedsprayer withoutengineering controlsScenarios 7 & 8,Hand-held sprayer withhydraulic nozzles,High level targetChartNumberRQ1 2.82 3.63 4.74 5.45 5.76 83Crop/UseBerries,vegetables,cerealsMethod <strong>of</strong> <strong>Application</strong> and ControlsEquipment Details ControlsHigh or lowboomMechanical transfer, enclosed filtered cab, A1P2 + gloves <strong>for</strong>mixing/loading, overalls + boots+ gloves <strong>for</strong> applicationEnclosed filtered cab,A1P2 + gloves <strong>for</strong> mixing/loadingMechanical transfer, A1P2 + hood/visor + overalls + boots + gloves<strong>for</strong> applicationA1P2+gloves <strong>for</strong> mixing/loading, A1P2 + hood/ visor + overalls +boots + gloves <strong>for</strong> applicationGloves <strong>for</strong> mixing/loading, hood/visor + overalls + boots + gloves<strong>for</strong> applicationGloves <strong>for</strong> mixing/loading, gloves <strong>for</strong> applicationFormulation<strong>Application</strong>rate7 218 No PPE 18 7Mechanical transfer system, enclosed filtered cab, A1P2 + gloves<strong>for</strong> mixing/loading, overalls + boots + gloves <strong>for</strong> application9 8 Fine-medium droplets Enclosed filtered cab, A1P2 + gloves <strong>for</strong> mixing/loadingECMechanical transfer system, A1P2 + hood/visor + overalls+ boots10 27+ gloves <strong>for</strong> applicationFruitA1P2+gloves <strong>for</strong> mixing/loading, A1P2 + hood/ visor + overalls +11 28 (tamarillo, Airblastboots + gloves <strong>for</strong> applicationpersimmons)Gloves <strong>for</strong> mixing/loading, hood/visor + overalls + boots + gloves12 32<strong>for</strong> application2052g a.i./ha 8 ha 113 547Gloves <strong>for</strong> mixing/loading, gloves <strong>for</strong> application14 702 No PPE15 11A1P2+gloves <strong>for</strong> mixing/loading, A1P2 + hood/ visor + overalls +boots + gloves <strong>for</strong> applicationGloves <strong>for</strong> mixing/loading, hood/visor + overalls + boots + gloves16 15Hand-heldPassion fruit<strong>for</strong> applicationsprayerGloves <strong>for</strong> mixing/loading, gloves <strong>for</strong> application17 10418 774 No PPEScenarios 9 & 10, five 19 8.3 GlasshouseGloves <strong>for</strong> mixing/loadingExposure only at RTU7L RTU cylinderscrops20 2.1 Fogging cylinder connection & Air-hose/SCBA respirator + gloves <strong>for</strong> mixing/loadingScenarios 9 & 10, one 21 1.7 Automatic/ disconnectionGloves <strong>for</strong> mixing/loadingMushroom35L RTU cylinder22 0.6 remoteHalf-face respirator + gloves <strong>for</strong> mixing/loadingroomsScenarios 11 & 12 23 9.8applicationA1P2 + gloves <strong>for</strong> mixing/loadingExposure only atScenarios 13 & 14 24 0.8mixing/loadingA1P2 + gloves <strong>for</strong> mixing/loadingScenarios 15 & 16 25 4Glasshouseflowerproduction(Cymbidiumsp.)ManualapplicationExposure at mixing,loading and applicationA1P2 + gloves <strong>for</strong> mixing/loading, A1P2 + hood/visor +overalls +boots + gloves <strong>for</strong> applicationRTU gasECArea orvolumetreated800 g a.i./ha 20 haNo. <strong>Application</strong>sModelled1026 g a.i./ha 1 ha 13 25000 m30.05 g a.i./m(1 ha)1300 g a.i./ha1800 g a.i./ha.01 ha(2500 m 3 )0.2 ha(5000 m 3 )111111111Dichlorvos reassessment – application Page 379 <strong>of</strong> 436
Open SpacePublic SpaceManual Fogging<strong>Application</strong>sEnclosedSpaceDomestic UseEnclosed Space Industrial UseReport Scenario Groupand NumberScenarios 17 & 18, one7L RTU cylinderScenarios 17 & 18, two7L RTU cylindersScenario 19Scenario 20 & 21Scenarios 22 & 23Scenarios 24 & 25Scenarios 26-27surface applicationScenarios 28-29Surface/creviceChartNumberRQCrop/UseMethod <strong>of</strong> <strong>Application</strong> and ControlsEquipment Details ControlsFormulation<strong>Application</strong>rate26 1.7FoggingGloves <strong>for</strong> mixing/loading375 m 3Exposure only at RTU27 0.6 Automatic/Half-face respirator <strong>for</strong> mixing/loading 3750 m 3cylinder connection &28 1.1 remoteHalf-face respirator + gloves <strong>for</strong> mixing/loading 12500 m 3disconnection29 0.9 applicationFull-face RPE + gloves 12500 m 330 0.8Half-face respirator + gloves <strong>for</strong> mixing/loading, no PPE <strong>for</strong>375 m 3applicationHalf-face respirator + gloves <strong>for</strong> mixing/loading, full-face RPE +RTU gas 0.05 g a.i./m 3 3750 m 3131 1.9chem. resistant full body + boots + gloves <strong>for</strong> applicationFoggingExposure at mixing, Half-face respirator + gloves <strong>for</strong> mixing/loading, air hose RPE +3750 m 332 0.1Manualloading and application chem. resistant full body + boots + gloves <strong>for</strong> applicationapplicationFull-face respirator + gloves <strong>for</strong> mixing/loading, full-face RPE +12500 m 333 6chem. resistant full body + boots + gloves <strong>for</strong> application34 1.2Full-face respirator + gloves <strong>for</strong> mixing/loading, air hose RPE +12500 m 3chem. resistant full body + boots + gloves <strong>for</strong> application35 0.1375 m 336 1.2 Fogging0.05 g a.i./m 3 3750 m 337 3.9 Automatic/ Exposure only at12500 m 3A1P2 + gloves <strong>for</strong> mixing and loading38 0.4remote mixing/loading375 m 3139 3.6 application0.15 g a.i./m 3 3750 m 3404190.1Industrial usepest controlA1P2 + gloves <strong>for</strong> mixing/loading, half-face RPE + overalls+ gloves<strong>for</strong> application12500 m 3375 m 342 1.3A1P2 + gloves <strong>for</strong> mixing/loading, air-hose RPE + chem.. resistant0.05 g a.i./m 3 3750 m 3full-body + boots + gloves <strong>for</strong> applicationA1P2 + gloves <strong>for</strong> mixing/loading, air-hose RPE + chem.. resistant12500 m 343 4.2Fogging Exposure atfull-body + boots + gloves <strong>for</strong> applicationManual mixing/loading andA1P2 + gloves <strong>for</strong> mixing/loading, half-face RPE + overalls+ gloves44 0.5application applicationEC375 m 3<strong>for</strong> application145 3.8A1P2 + gloves <strong>for</strong> mixing/loading, air-hose RPE + chem.. resistant0.15 g a.i./m 3 3750 m 3full-body + boots + gloves <strong>for</strong> application46 13A1P2 + gloves <strong>for</strong> mixing/loading, air-hose RPE + chem.. resistant12500 m 3full-body + boots + gloves <strong>for</strong> application47 0.4Half-face RPE + chem.. resistant full-body + boots + gloves <strong>for</strong>0.1 g a.i./m 2 150 m 2mixing, loading and applicationAir hose RPE + chem.. resistant full-body + boots + gloves <strong>for</strong>0.1 g a.i./m 2 1500 m 248 2High Exposure atmixing, loading and applicationpressure mixing/loading andAir hose RPE + chem.. resistant full-body + boots + gloves <strong>for</strong>0.1 g a.i./m 2 2500 m 249 4hand wand applicationmixing, loading and application150 0.7Air hose RPE + chem.. resistant full-body + boots + gloves <strong>for</strong>2 150 m20.3 g a.i./mmixing, loading and application51 4.9 Domestic use52 109 Domestic useRTU gascan surfaceapplicationRTU spraymixesExposure only duringapplicationExposure only duringapplicationArea orvolumetreatedNo. <strong>Application</strong>sModelledNone RTU gas 0.25 g a.i./m 2 7.44 m 2 1None RTU spray 0.3 g a.i./m 2 60 m 2 1Scenario 3053 754 7Open SpacePublic SpaceFoggingManualapplicationExposure duringmixing/loading andapplicationHalf-face respirator + chem. resistant full-body + boots + gloves<strong>for</strong> mixing, loading and applicationAir hose RPE + chem. resistant full-body + boots + gloves <strong>for</strong>mixing, loading and application0.1 g a.i./m 2 1 ha 1Dichlorvos reassessment – application Page 380 <strong>of</strong> 436
Appendix H: Qualitative Descriptors <strong>for</strong> Risk/Benefit AssessmentQualitative descriptors are indicative only and <strong>the</strong>y are primarily intended to be used to rankrisks and benefits <strong>for</strong> <strong>the</strong> purposes <strong>of</strong> balancing risks and costs against benefits, and so thatrisks can be prioritised <strong>for</strong> management. The ‗descriptor‘ words should not be seen in anyabsolute senses – <strong>the</strong>y are simply a means <strong>of</strong> differentiating levels <strong>of</strong> significance.Assessing risks, costs and benefits qualitatively1.1. This section describes how ERMA New Zealand staff and <strong>the</strong> Authority address <strong>the</strong>qualitative assessment <strong>of</strong> risks, costs and benefits. Risks and benefits are assessed byestimating <strong>the</strong> magnitude and nature <strong>of</strong> <strong>the</strong> possible effects and <strong>the</strong> likelihood <strong>of</strong> <strong>the</strong>iroccurrence. For each effect, <strong>the</strong> combination <strong>of</strong> <strong>the</strong>se two components determines<strong>the</strong> level <strong>of</strong> <strong>the</strong> risk associated with that effect, which is a two dimensional concept.Because <strong>of</strong> lack <strong>of</strong> data, risks are <strong>of</strong>ten presented as singular results. In reality, <strong>the</strong>yare better represented by ‗families‘ <strong>of</strong> data which link probability with differentlevels <strong>of</strong> outcome (magnitude).1.2. The magnitude <strong>of</strong> effect is described in terms <strong>of</strong> <strong>the</strong> element that might be affected.The qualitative descriptors <strong>for</strong> magnitude <strong>of</strong> effect are surrogate measures that shouldbe used to gauge <strong>the</strong> end effect or <strong>the</strong> ‗what if‘ element. Tables H4.1 and H4.2contain generic descriptors <strong>for</strong> magnitude <strong>of</strong> adverse and beneficial effect. Thesedescriptors are examples only, and <strong>the</strong>ir generic nature means that it may be difficultto use <strong>the</strong>m in some particular circumstances. They are included here to illustratehow qualitative tables may be used to represent levels <strong>of</strong> adverse and beneficialeffect.Table H4.1 Magnitude <strong>of</strong> adverse effect (risks and costs)Descriptor Examples <strong>of</strong> descriptions - AdverseMinimalMinorModerateMild reversible short term adverse health effects to individuals in highly localised areaHighly localised and contained environmental impact, affecting a few (less than ten)individuals members <strong>of</strong> communities <strong>of</strong> flora or fauna, no discernible ecosystem impactLocal/regional short-term adverse economic effects on small organisations (businesses,individuals), temporary job lossesNo social disruptionMild reversible short term adverse health effects to identified and isolated groupsLocalised and contained reversible environmental impact, some local plant or animalcommunities temporarily damaged, no discernible ecosystem impact or species damageRegional adverse economic effects on small organisations (businesses, individuals) lastingless than six months, temporary job lossesPotential social disruption (community placed on alert)Minor irreversible health effects to individuals and/or reversible medium term adversehealth effects to larger (but surrounding) community (requiring hospitalisation)Measurable long term damage to local plant and animal communities, but no obviousspread beyond defined boundaries, medium term individual ecosystem damage, no speciesdamageMedium term (one to five years) regional adverse economic effects with some nationalimplications, medium term job lossesSome social disruption (e.g. people delayed)Dichlorvos reassessment – application Page 381 <strong>of</strong> 436
MajorMassiveSignificant irreversible adverse health effects affecting individuals and requiringhospitalisation and/or reversible adverse health effects reaching beyond <strong>the</strong> immediatecommunityLong term/irreversible damage to localised ecosystem but no species lossMeasurable adverse effect on GDP, some long term (more than five years) job lossesSocial disruption to surrounding community, including some evacuationsSignificant irreversible adverse health effects reaching beyond <strong>the</strong> immediate communityand/or deathsExtensive irreversible ecosystem damage, including species lossSignificant on-going adverse effect on GDP, long term job losses on a national basisMajor social disruption with entire surrounding area evacuated and impacts on widercommunityTable H4.2 Magnitude <strong>of</strong> beneficial effect (benefits)Descriptor Examples <strong>of</strong> descriptions - BeneficialMinimalMinorModerateMajorMassiveMild short term positive health effects to individuals in highly localised areaHighly localised and contained environmental impact, affecting a few (less than ten)individuals members <strong>of</strong> communities <strong>of</strong> flora or fauna, no discernible ecosystem impactLocal/regional short-term beneficial economic effects on small organisations (businesses,individuals), temporary job creationNo social effectMild short term beneficial health effects to identified and isolated groupsLocalised and contained beneficial environmental impact, no discernible ecosystemimpactRegional beneficial economic effects on small organisations (businesses, individuals)lasting less than six months, temporary job creationMinor localised community benefitMinor health benefits to individuals and/or medium term health impacts on larger (butsurrounding) community and health status groupsMeasurable benefit to localised plant and animal communities expected to pertain tomedium termMedium term (one to five years) regional beneficial economic effects with some nationalimplications, medium term job creationLocal community and some individuals beyond immediate community receive socialbenefit.Significant beneficial health effects to localised community and specific groups in widercommunityLong term benefit to localised ecosystem(s)Measurable beneficial effect on GDP, some long term (more than five years) job creationSubstantial social benefit to surrounding community, and individuals in wider community.Significant long term beneficial health effects to <strong>the</strong> wider communityLong term, wide spread benefits to species and/or ecosystemsSignificant on-going effect beneficial on GDP, long term job creation on a national basisMajor social benefit affecting wider communityDichlorvos reassessment – application Page 382 <strong>of</strong> 436
1.3. The likelihood applies to <strong>the</strong> composite likelihood <strong>of</strong> <strong>the</strong> end effect, and not ei<strong>the</strong>r to<strong>the</strong> initiating event, or any one <strong>of</strong> <strong>the</strong> intermediary events. It includes:<strong>the</strong> concept <strong>of</strong> an initiating event (triggering <strong>the</strong> hazard), and<strong>the</strong> exposure pathway that links <strong>the</strong> source (hazard) and <strong>the</strong> area <strong>of</strong>impact (public health, environment, economy, or community).1.4. Thus, <strong>the</strong> likelihood is not <strong>the</strong> likelihood <strong>of</strong> an organism escaping, or <strong>the</strong> frequency<strong>of</strong> accidents <strong>for</strong> trucks containing hazardous substances, but <strong>the</strong> likelihood <strong>of</strong> <strong>the</strong>specified adverse effect 9 resulting from that initiating event. It will be a combination<strong>of</strong> <strong>the</strong> likelihood <strong>of</strong> <strong>the</strong> initiating event and several intermediary likelihoods 10 . Thebest way to determine <strong>the</strong> likelihood is to specify and analyse <strong>the</strong> complete pathwayfrom source to impact.1.5. Likelihood may be expressed as a frequency or a probability. While frequency is<strong>of</strong>ten expressed as a number <strong>of</strong> events within a given time period, it may also beexpressed as <strong>the</strong> number <strong>of</strong> events per head <strong>of</strong> (exposed) population. As aprobability, <strong>the</strong> likelihood is dimensionless and refers to <strong>the</strong> number <strong>of</strong> events <strong>of</strong>interest divided by <strong>the</strong> total number <strong>of</strong> events (range 0-1).Table H4.3 LikelihoodDescriptor DescriptionHighly improbableVery unlikelyUnlikely(occasional)LikelyHighly likelyAlmost certainly not occurring but cannot be totally ruled outConsidered only to occur in very unusual circumstancesCould occur, but is not expected to occur <strong>under</strong> normal operating conditionsA good chance that it may occur <strong>under</strong> normal operating conditionsAlmost certain, or expected to occur if all conditions met1.6. Using <strong>the</strong> magnitude and likelihood tables a matrix representing a level <strong>of</strong>risk/benefit can be constructed.1.7. In <strong>the</strong> example shown in Table H4.4, four levels <strong>of</strong> risk/benefit are allocated: A(negligible), B (low), C (medium), and D (high). These terms have been used toavoid confusion with <strong>the</strong> descriptions used <strong>for</strong> likelihood and magnitude, and toemphasise that <strong>the</strong> matrix is a tool to help decide which risks/benefits require fur<strong>the</strong>ranalysis to determine <strong>the</strong>ir significance in <strong>the</strong> decision making process.1.8. For negative effects, <strong>the</strong> levels are used to show how risks can be reduced by <strong>the</strong>application <strong>of</strong> additional controls. Where <strong>the</strong> table is used <strong>for</strong> positive effects it mayalso be possible <strong>for</strong> controls to be applied to ensure that a particular level <strong>of</strong> benefitis achieved, but this is not a common approach. The purpose <strong>of</strong> developing <strong>the</strong>tables <strong>for</strong> both risk and benefit is so that <strong>the</strong> risks and benefits can be compared.910The specified effect refers to scenarios established in order to establish <strong>the</strong> representative risk, and may beas specific as x people suffering adverse health effects, or y% <strong>of</strong> a bird population being adversely affected.The risks included in <strong>the</strong> analysis may be those related to a single scenario, or may be defined as acombination <strong>of</strong> several scenarios.Qualitative event tree analysis may be a useful way <strong>of</strong> ensuring that all aspects are included.Dichlorvos reassessment – application Page 383 <strong>of</strong> 436
Table H4.4Level <strong>of</strong> riskMagnitude <strong>of</strong> effectLikelihood Minimal Minor Moderate Major MassiveHighly improbable A A A B BVery unlikely A A B B CUnlikely A B B C CLikely B B C C DHighly likely B C C D DDichlorvos reassessment – application Page 384 <strong>of</strong> 436
Appendix I: Data from which classifications derived by mixturerules were derivedComposition <strong>of</strong> dichlorvos <strong>for</strong>mulationsName/CodeMaximum Concentration(% w/w)Emulsifiableconcentratecontaining1000 g/litredichlorvosEmulsifiableconcentratecontaining1140 g/litredichlorvosAerosolcontaining 50g/kgdichlorvosFlammableaerosolcontaining 3.1g/litredichlorvosand 8.7 g/litrepropoxurReady to useliquidcontaining 4.4g/litredichlorvosand 9.6 g/litrepropoxurDDVPInsecticideStripJ72.03Dichlorvos 70.7 82.6 5 0.45 0.45 22 24Propoxur 1.3 1A 15B 6.9 14C 0.14D 95 95E 47F 24G 19H 8.2I 79J 8.4K 7L 18M 5.1N 1 +N 2 0.059N 3 0.44N 4 0.0076N 5 0.0038N 6 0.036N 7 0.0065N 8 0.041N 9 0.1N 10 4.7N 11 0.0049O 0.07P +Q 52Dichlorvos reassessment – application Page 385 <strong>of</strong> 436
Toxicity and environmental data on which classifications were basedEndpoint Units * Dichlorvos Propoxur A B C D E F G H I J KAcute toxicity – oralAcute toxicity- dermalAcute toxicity –inhalationIf classified(mg/kg bw/d)If classified(mg/kg bw/d)If classified(mg/kg bw/d)46.4 23.5 4840 2590 1086 N/A 3600 ND N/A N/A No 300 180075 800 No 2830 ND No No ND ND ND No 210 ND0.447 0.654 ND ND ND No No ND No No No 2.21 NDSkin irritation Classification 6.3B No No 6.3B 6.3A No 6.3B 6.3B No No No 6.3B 6.3BEye irritation Classification 6.4A 6.4A 6.4A 6.4A 8.3A No 6.4A ND No No No 6.4A 8.3ASensitization Classification 6.5B No ND ND No No No ND ND ND No No NDMutagenicity Classification 6.6B No ND ND No No ND ND ND ND No No NDCarcinogenicity Classification 6.7B 6.7B ND ND ND No ND ND ND No No ND NDReproductive toxicity Classification No No 6.8A ND No No No ND No ND No No NDTarget organ toxicity Classification 6.9A 6.9A No ND No No ND ND No No No No NDAquatic toxicity Classification (MF) 9.1A (10000) 9.1D 9.1A(1)9.1B 9.1D No No 9.1B No No No No 9.1BBioaccumulation Yes/No No No No No No No No Yes No No N/A No YesRapidly biodegradable Yes/No Yes No Yes No Yes No Yes No Yes Yes N/A Yes YesSoil toxicity Classification (MF) 9.2B 9.2B No ND No No No ND ND ND No ND 9.2A(1)Soil DT50>30 d Yes/No No Yes Yes No No No No Yes No No N/A Yes YesVertebrate toxicity Classification (MF) 9.3A(1)9.3A(10)No No 9.3C No No ND N/A N/A No 9.3B 9.3CInvertebrate toxicity Classification (MF) 9.4A 9.4A ND ND ND No ND ND ND ND No ND NDDichlorvos reassessment – application Page 386 <strong>of</strong> 436
Endpoint Units * Dichlorvos Propoxur A B C D E F G H I J K(10) (1)Endpoint Units * L M N 1N 2 N 3 N 4 N 5 N 6 N 7 N 8 N 9 N 10 N 11 O P QAcute toxicity –oralAcute toxicitydermalAcute toxicity –inhalationIf classified(mg/kg bw/d)If classified(mg/kg bw/d)If classified(mg/kg bw/d)No No ND ND No 500 2000 No 2000 650 No No 500 No No NoNo No ND ND ND ND ND ND ND ND ND No 1100 ND ND NoND ND ND ND ND ND ND ND ND ND ND ND ND No ND NDSkin irritation Classification No No ND ND ND 8.2B No ND No No No 6.3B 8.2C No No NoEye irritation Classification No No ND ND ND 8.3A No ND No No No No 8.3A No No NoSensitization Classification No ND ND ND 6.5B No ND ND ND 6.5B No No ND No ND NoMutagenicity Classification No ND ND ND ND No No ND No No ND No ND No No NDCarcinogenicity Classification No ND ND ND ND No No ND No No ND No ND No ND NDReproductivetoxicityTarget organtoxicityAquatic toxicityClassification ND ND ND ND ND No No ND No No No No 6.8B ND No NDClassification No ND ND ND No ND No ND No 6.9B No ND 6.9B ND No NoClassification(MF)9.1A(1)ND ND ND 9.1A(1)9.1A(10)No 9.1D No 9.1D ND 9.1B 9.1C No No NoBioaccumulation Yes/No No Yes Yes Yes Yes Yes No Yes No Yes Yes Yes Yes No No NoRapidlybiodegradableSoil toxicityYes/No Yes No No No No No Yes Yes Yes No No Yes No No No NoClassification(MF)ND ND ND ND ND 9.2C ND ND ND ND ND ND 9.2C ND No NoSoil DT50>30 d Yes/No No Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes No Yes YesDichlorvos reassessment – application Page 387 <strong>of</strong> 436
Endpoint Units * L M N 1N 2 N 3 N 4 N 5 N 6 N 7 N 8 N 9 N 10 N 11 O P QVertebratetoxicityInvertebratetoxicityClassification(MF)Classification(MF)No ND ND ND ND 9.2C 9.3C No ND 9.3C No No 9.3C No No NoND ND ND ND ND ND ND ND ND ND ND ND ND ND ND No* MF – multiplication factor if 9.XADichlorvos reassessment – application Page 388 <strong>of</strong> 436
Toxicity mixture calculationsSubclass 6.1 Acute toxicity - additivity <strong>for</strong>mula1.1 Using <strong>the</strong> additivity <strong>for</strong>mula from <strong>the</strong> ERMA New Zealand User Guide to HSNOThresholds and Classifications <strong>the</strong> mixture LD 50 calculation <strong>for</strong> acute oral, dermaland inhalation toxicity <strong>for</strong> dichlorvos <strong>for</strong>mulations was calculated as follows:Calculated mixture LD 50 =%ComponentLD Component50100Subclass 6.3 Skin Irritation and Subclass 8.2 Skin corrosion1.2 The mechanism <strong>for</strong> assigning skin irritation/corrosion classification to mixtures(assuming product data are not available) is by analysis <strong>of</strong> component data, asdescribed in <strong>the</strong> ERMA New Zealand User Guide to Thresholds and Classification,Table 11.3, Part V, Chapter 11, Page 10. The relevant mixture rules based on <strong>the</strong>composition and hazard pr<strong>of</strong>ile <strong>of</strong> <strong>the</strong> dichlorvos <strong>for</strong>mulations are:1. ∑ 8.2X components ≥ 5%, classify as 8.2X2. ∑ 8.2X components ≥1 but < 5%, classify as 6.3A3. ∑ (10 x 8.2X components) + 6.3A components ≥ 10%, classify as 6.3A.4. ∑ (10 x 8.2X components) + 6.3A components ≥ 1 but < 10%, classify as 6.3B.5. ∑ (10 x 8.2X components) + 6.3A components + 6.3B components ≥ 10%,classify as 6.3B.6. ∑ 6.3A components ≥ 10%, classify as 6.3A.7. ∑ 6.3A components ≥ 1% but < 10%, classify as 6.3B8. ∑ 6.3B components ≥ 10%, classify as 6.3B.Subclass 6.4 Eye Irritation and Subclass 8.3 Eye Corrosion1.3 The mechanism <strong>for</strong> assigning eye irritation/corrosion classification to mixtures(assuming product data are not available) is by analysis <strong>of</strong> component data, asdescribed in <strong>the</strong> ERMA New Zealand User Guide to Thresholds and Classification,Table 12.3, Part V, Chapter 12, Page 12. The relevant mixture rules based on <strong>the</strong>composition and hazard pr<strong>of</strong>ile <strong>of</strong> <strong>the</strong> dichlorvos <strong>for</strong>mulations are:1. ∑ 8.3A components ≥ 3% classify as 8.3A2. ∑ 8.3A components ≥ 1% but > 3%, classify as 6.4A3. ∑ (10 x x8.3A components) + 6.4A components ≥ 10%, classify as 6.4A.4. ∑ 6.4A components ≥ 10%, classify as 6.4A.Dichlorvos reassessment – application Page 389 <strong>of</strong> 436
Ecotoxicity mixture calculationsSubclass 9.1 – Aquatic Ecotoxicity - Summation method1.4 Apply summation method <strong>for</strong> classification <strong>of</strong> mixtures <strong>for</strong> aquatic ecotoxicity (referERMA New Zealand User Guide to HSNO Thresholds and Classifications, Part VI,Chapter 19, page 20):Level 1: 9.1A x MIf ≥25%, <strong>the</strong>n 9.1ALevel 2:Level 3:(M x 10 x 9.1A) + 9.1BIf ≥25%, <strong>the</strong>n 9.1B*(M x 100 x 9.1A) + (10 x 9.1B) + 9.1CIf ≥25%, <strong>the</strong>n 9.1C*Level 4: 9.1A + 9.1B + 9.1C + 9.1DIf ≥25%, <strong>the</strong>n 9.1D* If a mixture is classified as 9.1B or 9.1C and <strong>the</strong> weighted sum <strong>of</strong> components that are notrapidly degradable or are bioaccumulative is < 25% <strong>the</strong>n <strong>the</strong> mixture is assigned <strong>the</strong>classification at <strong>the</strong> step below, ie 9.1B reduces to 9.1C, and 9.1C to 9.1D.Level 1:< ≥ 25% NOT 9.1ALevel 2:< ≥25% NOT 9.1BLevel 3:< ≥25% NOT 9.1CLevel 4:< ≥25% NOT 9.1DSubclass 9.2 – Soil Ecotoxicity - Summation method1.5 Apply summation method <strong>for</strong> classification <strong>of</strong> mixtures <strong>for</strong> soil ecotoxicity (referERMA New Zealand User Guide to HSNO Thresholds and Classifications, Part VI,Chapter 20, Page 10):Level 1:9.2A x M If ≥25%, <strong>the</strong>n 9.2ALevel 2:(M x 10 x 9.2A) + 9.2BIf ≥25%, <strong>the</strong>n 9.2BLevel 3:(M x 100 x 9.2A) + (10 x 9.2B) + 9.2CIf ≥25%, <strong>the</strong>n 9.2C*Level 4:9.2A + 9.2B + 9.2C + 9.2DIf ≥25%, <strong>the</strong>n 9.2D* unless <strong>the</strong> weighted sum <strong>of</strong> components with DT >30 days (or no data on degradation) is
Subclass 9.3 –Ecotoxicity to terrestrial vertebrates - Summation method1.6 Apply summation method <strong>for</strong> classification <strong>of</strong> mixtures <strong>for</strong> terrestrial vertebratesecotoxicity (refer ERMA New Zealand User Guide to HSNO Thresholds andClassifications, Part VI, Chapter 21, Page 9):Level 1:9.3A x M If ≥25%, <strong>the</strong>n 9.3ALevel 2:(M x 10 x 9.3A) + 9.3BIf ≥25%, <strong>the</strong>n 9.3BLevel 3:(M x 100 x 9.3A) + (10 x 9.3B) + 9.3CIf ≥25%, <strong>the</strong>n 9.3CLevel 1:< ≥ 25% NOT 9.3ALevel 2:< ≥25% NOT 9.3BLevel 3:< ≥25% NOT 9.3CSubclass 9.4 –Ecotoxicity to terrestrial invertebrates - Summation method1.7 Apply summation method <strong>for</strong> classification <strong>of</strong> mixtures terrestrial invertebrates (referERMA New Zealand User Guide to HSNO Thresholds and Classifications, Part VI,Chapter 22, Page 7):Level 1:9.4A x M If ≥25%, <strong>the</strong>n 9.4ALevel 2:(M x 10 x 9.4A) + 9.4BIf ≥25%, <strong>the</strong>n 9.4BLevel 3:(M x 100 x 9.4A) + (10 x 9.4B) + 9.4CIf ≥25%, <strong>the</strong>n 9.4CLevel 1:< ≥ 25% NOT 9.4ALevel 2:< ≥25% NOT 9.4BLevel 3:< ≥25% NOT 9.4CDichlorvos reassessment – application Page 391 <strong>of</strong> 436
Appendix J: Current ControlsHSNO Act controls1.1 The controls applicable to dichlorvos and its <strong>for</strong>mulations are given in Table J.1.The control codes, as given in Table J.1, are codes ERMA New Zealand hasassigned to enable easy cross-referencing to <strong>the</strong> regulations. These codes aredetailed in ERMA New Zealand (2001).1.2 Where a control has been changed from <strong>the</strong> default wording specified in <strong>the</strong> HSNORegulations, this is indicated by a star (*) next to <strong>the</strong> control code. The detail <strong>of</strong> thischange, including deletion <strong>of</strong> a control, is listed <strong>under</strong> Changes to Controls in TableJ.2.Dichlorvos reassessment – application Page 392 <strong>of</strong> 436
Table J.1:Existing controls <strong>for</strong> dichlorvos and its <strong>for</strong>mulations<strong>Substance</strong>HSNO Control Dichlorvos Ready touse liquidcontaining4.4 g/ldichlorvos& 9.6 g/lpropoxurClass 1 to 5controlsClass 6, 8and 9controlsEmulsifiableconcentratecontaining 1000g/l dichlorvosAerosolcontaining50 g/kgdichlorvosEmulsifiableconcentratecontaining1140 g/ldichlorvosFlammableaerosolcontaining3.1 g/ldichlorvosand 8.7 g/lpropoxurDDVPinsecticidestrip(a) (b) (c) (d) (e) (f) (g) (h)F1 F2 F3 F4 f F5 F6 F11 F12 F14 fF16T1 b c d e f g h T2 x g h T3 x hT4 T5 T6 a x b c d e f g h T7 x hE1 a b c d e f x g E2 c f x g x hJ72.03Dichlorvos reassessment – application Page 393 <strong>of</strong> 436
PackagingcontrolsDisposalcontrolsEmergencymanagementcontrolsApprovedHandlercontrolsE3 x hE5 x hE6 x hE7 a x b c d e f g h P1 P3 P13 a c e P14 P15 PG1 PG2 PG3 PS4 D2 D4 D5 D6 D7 x hD8 EM1 EM2 eEM6 x hEM7 x hEM8 EM9 EM10 EM11 EM12 a b c e f g EM13 AH1 h Dichlorvos reassessment – application Page 394 <strong>of</strong> 436
TrackingcontrolsIdentification controlsTR1 x b x f h I1 I2 I3 I5 I8 I9 I10 I11 h I13 I16 h I17 I18 I19 I20 I21 I22 I23 I25 I28 I29 I30 Dichlorvos reassessment – application Page 395 <strong>of</strong> 436
Controlsrelating toStationaryContainerSystems,SecondaryContainmentandUnintendedIgnition <strong>of</strong>Flammable<strong>Substance</strong>sCompressedGas ControlsGN35A f CG Key: Control applied nx nControl applied but varied <strong>for</strong> substance “n” (refer to Code description)Control not triggeredControl triggered but deleted by variation <strong>for</strong> substance “n” (refer to Code description) Control not triggered because <strong>of</strong> proposed change <strong>of</strong> classification <strong>of</strong> substanceDichlorvos reassessment – application Page 396 <strong>of</strong> 436
Table J.2:Summary <strong>of</strong> default controls applicable to dichlorvos (variations apply to <strong>the</strong>corresponding substance (a) to (h)).<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 1 to 5 Controls) Regulations 2001Code F1 Reg 7 General test certification requirements <strong>for</strong> hazardoussubstance locationsCode F2 Reg 8 Restrictions on <strong>the</strong> carriage <strong>of</strong> flammable substances onpassenger service vehiclesCode F3 Reg 55 General limits on flammable substancesCode F4 Reg 56 Approved handler/security requirements <strong>for</strong> certainflammable substancesvariation:fChanges to Default ControlRegulation 56 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 1 to5 Controls) Regulations 2001The following regulation is inserted immediately afterregulation 56:56A Exception to approved handler requirement <strong>for</strong>transportation <strong>of</strong> packaged pesticides(1) Regulation 56 is deemed to be complied with if:(a) when this substance is being transported on land—(i) by rail, <strong>the</strong> person who drives <strong>the</strong> rail vehicle that istransporting <strong>the</strong> substance is fully trained in accordancewith <strong>the</strong> approved safety system <strong>for</strong> <strong>the</strong> time beingapproved <strong>under</strong> section 6D <strong>of</strong> <strong>the</strong> Transport ServicesLicensing Act 1989; and(ii) o<strong>the</strong>r than by rail, <strong>the</strong> person who drives, loads, andunloads <strong>the</strong> vehicle that is transporting <strong>the</strong> substance has acurrent dangerous goods endorsement on his or her driverlicence; and(iii) in all cases, Land Transport Rule: Dangerous Goods1999 (Rule 45001) is complied with; or(b) when this substance is being transported by sea, one <strong>of</strong><strong>the</strong> following is complied with:(i) Maritime Rules: Part 24A – Carriage <strong>of</strong> Cargoes –Dangerous Goods (MR024A):(ii)International Maritime Dangerous Goods Code; or(c) when this substance is being transported by air, Part92 <strong>of</strong> <strong>the</strong> Civil Aviation Rules is complied with.(2) Subclause (1)(a)—(a) does not apply to a tank wagon or a transportablecontainer to which <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (TankDichlorvos reassessment – application Page 397 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 1 to 5 Controls) Regulations 2001Wagons and Transportable Containers) Regulations 2004applies; but(b) despite paragraph (a), does apply to an intermediatebulk container that complies with chapter 6.5 <strong>of</strong> <strong>the</strong> UNModel Regulations.(3) Subclause (1)(c)—(a) applies to pilots, aircrew, and airline ground personnelloading and managing this substance within an aerodrome;but(b) does not apply to—(i) <strong>the</strong> handling <strong>of</strong> this substance in any place that is notwithin an aerodrome; or(ii) <strong>the</strong> loading and managing <strong>of</strong> this substance <strong>for</strong> <strong>the</strong>purpose <strong>of</strong> aerial spraying or dropping.(4) In this regulation, UN Model Regulations means <strong>the</strong>13th revised edition <strong>of</strong> <strong>the</strong> Recommendation on <strong>the</strong>Transport <strong>of</strong> Dangerous Goods Model Regulations,published in 2003 by <strong>the</strong> United Nations.Code F5 Regs 58, 59 Requirements regarding hazardous atmosphere zones <strong>for</strong>class 2.1.1, 2.1.2 and 3.1 substancesCode F6 Regs 60 –70Requirements to prevent unintended ignition <strong>of</strong> class 2.1.1,2.1.2 and 3.1 substancesCode F11 Reg 76 Segregation <strong>of</strong> incompatible substancesCode F12 Reg 77 Requirement to establish a hazardous substance locations ifflammable substances are presentCode F14 Reg 81 Test certification requirements <strong>for</strong> facilities where class2.1.1, 2.1.2 or 3.1 substances are presentvariation:fChanges to Default ControlRegulation 81 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 1 to5 Controls) Regulations 2001A hazardous substance location does not require a testcertificate if—(a) <strong>the</strong> hazardous substance location is situated on a farm<strong>of</strong> not less than 4 hectares; and(b) <strong>the</strong> combined quantity <strong>of</strong> each class 3.1B or class 3.1Csubstance and any petrol, aviation gasoline, or racinggasoline stored at <strong>the</strong> location is less than 2,000 litres; and(c) ei<strong>the</strong>r—(i)<strong>the</strong> following requirements are complied with:(A) each substance is stored in 1 or more secure containers,each <strong>of</strong> which has a capacity <strong>of</strong> less than 250 litres; and(B) each container complies with regulation 11 andSchedule 2 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Packaging)Regulations 2001; andDichlorvos reassessment – application Page 398 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 1 to 5 Controls) Regulations 2001(C) each container is—(1) situated not less than 15 metres from any area <strong>of</strong> highintensity land use or area <strong>of</strong> regular habitation; and(2) situated ei<strong>the</strong>r in <strong>the</strong> open or in a well-ventilatedbuilding; and(3) in a compound or located so that any spillage <strong>of</strong> <strong>the</strong>substance will not endanger any building, or flow into anystream, lake, or natural water; or(ii) <strong>the</strong> following requirements are complied with:(A) each substance is stored in an above ground stationarytank that complies with <strong>the</strong> Stationary Container Controls inSchedule 8 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Dangerous Goodsand Scheduled Toxic <strong>Substance</strong>s) Transfer Notice 2004, asamended by this Schedule; and(B) each <strong>of</strong> <strong>the</strong> above ground stationary tanks is situated—(1) not less than 20 metres from any area <strong>of</strong> high-intensityland use or area <strong>of</strong> regular habitation; and(2) 6 metres from any combustible materials; and(3) in a compound or located so that any spillage <strong>of</strong> <strong>the</strong>substance will not endanger any building, or flow into anystream, lake, or natural water.Code F16 Reg 83 Controls on transit depots where flammable substances arepresent<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8, and 9 Controls) Regulations 2001Code T1 Regs 11 –27Limiting exposure to toxic substances through <strong>the</strong> setting <strong>of</strong>Tolerable Exposure Limits (TELs)note:b, c, d, e,f, gnote:gRegulations 11-27 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes6, 8, and 9 Controls) Regulations 2001No TELs are set at this time.Regulations 11-27 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes6, 8, and 9 Controls) Regulations 2001The following ADE is set:ADE (dichlorvos) = 0.004 mg/kg bw/dayvariation:hRegulations 11-27 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes6, 8, and 9 Controls) Regulations 2001The following TEL is set:For component A: TEL AIR 0.002 ppm.Code T2 Regs 29, 30 Controlling exposure in places <strong>of</strong> work through <strong>the</strong> setting<strong>of</strong> WESs.variation:gChanges to Default ControlsRegulations 29, 30 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes6, 8, and 9 Controls) Regulations 2001The properties and use pr<strong>of</strong>ile <strong>of</strong> DDVP Insecticide Stripsare such that <strong>the</strong> criteria <strong>under</strong> Regulation 29(1)(c) are notmet and this control is deleted.Dichlorvos reassessment – application Page 399 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8, and 9 Controls) Regulations 2001hRegulations 29, 30 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes6, 8, and 9 Controls) Regulations 2001The following WES applies:Component A (skin*): 8 Hour Time WeightedAverage 0.1ppm / 0.90 mg/m 3*The default excursion <strong>of</strong> three times <strong>the</strong> WES (0.3ppm/0.27 mg/m 3 ) <strong>for</strong> any 15 minute period applies.Code T3 Regs 5(1), 6 Requirements <strong>for</strong> keeping records <strong>of</strong> useCode T4 Reg 7 Requirements <strong>for</strong> equipment used to handle substancesvariation:Changes to Default Controlsh Regulation 7 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001The comtrol imposed by this regulation is only applicableduring <strong>the</strong> manufacturing stage <strong>of</strong> <strong>the</strong> substance‘s lifecycle.Code T5 Reg 8 Requirements <strong>for</strong> protective clothing and equipmentCode T6 Reg 9 Approved handler/security requirements <strong>for</strong> certain toxicsubstancesvariation:Changes to Default Controlsb Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulation 9 is omitted. You do not need to be an approvedhandler to use this substance.f Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001This regulation applies to each hazardous substancedescribed inSchedule 1 with variation code 3 as if subclause (1) wereomitted and<strong>the</strong> following substituted:(1) A hazardous substance to which this regulation appliesmust be <strong>under</strong> <strong>the</strong> personal control <strong>of</strong> an approved handlerwhen <strong>the</strong> substance is used by a commercial contractor.g Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulation 9 only applies during <strong>the</strong> use phase <strong>of</strong> <strong>the</strong>lifecycle.h Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulation 9 only applies during <strong>the</strong> manufacturing andtransport phases <strong>of</strong> <strong>the</strong> lifecycle.a, c, d, e,hRegulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001The following regulation were inserted immediately afterregulation 9:9A Exception to approved handler requirement <strong>for</strong>Dichlorvos reassessment – application Page 400 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8, and 9 Controls) Regulations 2001transportation <strong>of</strong> packaged class 6 substances(1) Regulation 9 is deemed to be complied with if—(a) in <strong>the</strong> case <strong>of</strong> a hazardous substance being transported onland—(i) in <strong>the</strong> case <strong>of</strong> a hazardous substance being transported byrail, <strong>the</strong> person who drives <strong>the</strong> rail vehicle that is transporting<strong>the</strong> substance is fully trained in accordance with an approvedsafety system <strong>under</strong> section 6D <strong>of</strong> <strong>the</strong> Transport ServicesLicensing Act 1989 or a safety system which is referred to inan approved safety case <strong>under</strong> <strong>the</strong> Railways Act 2005; and(ii) in every o<strong>the</strong>r case, <strong>the</strong> person who drives, loads, andunloads <strong>the</strong> vehicle that is transporting <strong>the</strong> substance—(A) <strong>for</strong> hire or reward, or in quantities which exceed those setout in Schedule 1 <strong>of</strong> <strong>the</strong> Land Transport Rule 45001/1:Dangerous Goods 2005, has a current dangerous goodsendorsement on his or her driver licence; or(B) in every o<strong>the</strong>r case, <strong>the</strong> Land Transport Rule 45001/1:Dangerous Goods 2005 is complied with; or(b) in <strong>the</strong> case <strong>of</strong> a hazardous substance being transported bysea, one <strong>of</strong> <strong>the</strong> following is complied with:(i) Maritime Rules: Part 24A – Carriage <strong>of</strong> Cargoes –Dangerous Goods (MR024A); or(ii) International Maritime Dangerous Goods Code; or(c) in <strong>the</strong> case <strong>of</strong> a hazardous substance being transported byair, Part 92 <strong>of</strong> <strong>the</strong> Civil Aviation Rules is complied with.(2) Subclause (1)(a)—(a) does not apply to a tank wagon or a transportable containerto which <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Tank Wagons andTransportable Containers) Regulations 2004 applies; but(b) despite paragraph (a), does apply to an intermediate bulkcontainer that complies with chapter 6.5 <strong>of</strong> <strong>the</strong> UN ModelRegulations.(3) Subclause (1)(c)—(a) applies to pilots, aircrew, and airline ground personnelloading and handling a hazardous substance within anaerodrome; but(b) does not apply to <strong>the</strong> storage and handling <strong>of</strong> a hazardoussubstance in any place that is not within an aerodrome orwithin an aerodrome by non-airline ground personnel.The following regulation was inserted immediately afterregulation 9A:9B Exception to approved handler requirement <strong>for</strong> aerialapplication <strong>of</strong> certain substancesRegulation 9 is deemed to be complied with if, in <strong>the</strong> case <strong>of</strong><strong>the</strong> aerial application <strong>of</strong> a hazardous substance, <strong>the</strong> personwho carries out <strong>the</strong> application has a current pilot chemicalrating in accordance with Part 61 <strong>of</strong> <strong>the</strong> Civil Aviation Rules.Code T7 Reg 10 Restrictions on <strong>the</strong> carriage <strong>of</strong> toxic or corrosive substanceson passenger service vehiclesvariation:Changes to Default ControlsThis regulation applies to this substance, as if each item inSchedule 2 <strong>of</strong> <strong>the</strong> regulations relatingto <strong>the</strong> specified hazard classification was replaced by:Hazard Classification Liquid (L) Solid (kg)6.5B 1 3Dichlorvos reassessment – application Page 401 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8, and 9 Controls) Regulations 2001Code E1 Regs 32–45 Limiting exposure to ecotoxic substances through <strong>the</strong> setting<strong>of</strong> Environmental Exposure Limits (EELs)variation:a, b, c, d,e, fChanges to Default ControlsRegulations 32 to 45 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Classes 6, 8, and 9 Controls) Regulations 2001No EELs are set at this time, and <strong>the</strong> default EELs given<strong>under</strong> regulation 32 are deleted.gRegulations 32 to 45 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Classes 6, 8, and 9 Controls) Regulations 2001The requirements to set EELs have been deleted <strong>for</strong> thissubstance.hRegulations 32 to 45 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Classes 6, 8, and 9 Controls) Regulations 2001The following EEL water is set:For component A: EEL water = 0.001 μg/LCode E2 Regs 46 –48variation:gRestrictions on use <strong>of</strong> substances in application areasChanges to Default ControlsRegulations 46 to 48 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Classes 6, 8, and 9 Controls) Regulations 2001The requirement to set a maximum application rate has beendeleted <strong>for</strong> this substance.Code E3 Reg 49 Controls relating to protection <strong>of</strong> terrestrial invertebrates egbeneficial insectsCode E5 Regs 5(2), 6 Requirements <strong>for</strong> keeping records <strong>of</strong> useCode E6 Reg 7 Requirements <strong>for</strong> equipment used to handle substancesCode E7 Reg 9 Approved handler/security requirements <strong>for</strong> certain ecotoxicsubstancesvariation:Change to Default Controlsa Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001This regulation applies as if dichlorvos is not a class 9substance.b Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001The regulations apply as if regulation 9 were omitted.f Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulation 9(1) is replaced by:(1) This substance must be <strong>under</strong> <strong>the</strong> personal control <strong>of</strong>an approved handler when <strong>the</strong> substance is—(a) used by a commercial contractor; or(b) applied directly onto or into water.Dichlorvos reassessment – application Page 402 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8, and 9 Controls) Regulations 2001g Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulation 9 only applies during <strong>the</strong> use phase <strong>of</strong> <strong>the</strong>lifecycle.h Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulation 9 only applies during <strong>the</strong> manufacturing andtransport phases <strong>of</strong> <strong>the</strong> lifecycle.c,d, e, h Regulation 9 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Classes 6, 8,and 9 Controls) Regulations 2001Regulations 9A and 9B added (see Code T6).<strong>Hazardous</strong> <strong>Substance</strong>s (Packaging) Regulations 2001Code P1 Regs 5, 6,7(1), 8General packaging requirementsCode P3 Reg 9 Criteria that allow substances to be packaged to a standard notmeeting Packing Group I, II or III criteriaCode P13 Reg 19 Packaging requirements <strong>for</strong> toxic substancesvariation:Changes to Default Controlsa, c, e This regulation applies as if ―Schedule 1‖ in subclause (1)(a)were omitted and substituted with ―Schedule 2‖ (i.e. CodePG2 is applied instead <strong>of</strong> Code PG1).Code P14 Reg 20 Packaging requirements <strong>for</strong> corrosive substancesCode P15 Reg 21 Packaging requirements <strong>for</strong> ecotoxic substancesCode PG1 Schedule 1 Packaging requirements equivalent to UN Packing Group ICode PG2 Schedule 2 Packaging requirements equivalent to UN Packing Group IICode PG3 Schedule 3 Packaging requirements equivalent to UN Packing Group IIICode PS4 Schedule 4 Packaging requirements as specified in Schedule 4<strong>Hazardous</strong> <strong>Substance</strong>s (Disposal) Regulations 2001Code D2 Reg 6 Disposal requirements <strong>for</strong> flammable substancesCode D4 Reg 8 Disposal requirements <strong>for</strong> toxic and corrosive substancesCode D5 Reg 9 Disposal requirements <strong>for</strong> ecotoxic substancesCode D6 Reg 10 Disposal requirements <strong>for</strong> packagesCode D7 Regs 11, 12 In<strong>for</strong>mation requirements <strong>for</strong> manufacturers, importers andsuppliers, and persons in chargeCode D8 Regs 13, 14 Documentation requirements <strong>for</strong> manufacturers, importers andsuppliers, and persons in chargeDichlorvos reassessment – application Page 403 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Personnel Qualifications) Regulations 2001Code AH1 Regs 4 – 6 Approved Handler requirements (including test certificate andqualification requirements)<strong>Hazardous</strong> <strong>Substance</strong>s (Tracking) Regulations 2001Code TR1 Regs 4(1), 5, 6 General tracking requirementsvariation:Changes to Default Controlsb, f Regulations 4 to 6 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Tracking)Regulations 2001Regulations 4 to 6 are deleted.ghRegulations 4 to 6 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Tracking)Regulations 2001Regulations 4 to 6 only apply to users <strong>of</strong> <strong>the</strong> substance.Regulations 4 to 6 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Tracking)Regulations 2001Regulations 4 to 6 only apply to while <strong>the</strong> substance is in NewZealand.<strong>Hazardous</strong> <strong>Substance</strong>s (Emergency Management) Regulations 2001Code EM1 Regs 6, 7, 9 –11Level 1 in<strong>for</strong>mation requirements <strong>for</strong> suppliers and persons inchargeCode EM2 8(a) In<strong>for</strong>mation requirements <strong>for</strong> corrosive substancesCode EM6 Reg 8(e) In<strong>for</strong>mation requirements <strong>for</strong> toxic substancesCode EM7 Reg 8(f) In<strong>for</strong>mation requirements <strong>for</strong> ecotoxic substancesCode EM8 Regs 12- 16,18- 20Level 2 in<strong>for</strong>mation requirements <strong>for</strong> suppliers and persons inchargeCode EM9 Reg 17 Additional in<strong>for</strong>mation requirements <strong>for</strong> flammable andoxidising substances and organic peroxidesCode EM10 Regs 21 – 24 Fire extinguisher requirementsCode EM11 Regs 25 – 34 Level 3 emergency management requirements: duties <strong>of</strong>person in charge, emergency response plansCode EM12 Regs 35 – 41 Level 3 emergency management requirements: secondarycontainmentvariation:Change to Default Controlsa, b, c, e, f, g Regulations 35- 42 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Emergency Management) Regulations 2001The following subclauses are added after subclause (3) <strong>of</strong>regulation 36:(4) For <strong>the</strong> purposes <strong>of</strong> this regulation, and regulations 37 to40, where this substance is contained in pipework that isinstalled and operated so as to manage any loss <strong>of</strong>containment in <strong>the</strong> pipework it—(a) is not to be taken into account in determiningwhe<strong>the</strong>r a place is required to hav a secondarycontainment system; and(b) is not required to be located in a secondarycontainment system.(5) In this clause, pipework—Dichlorvos reassessment – application Page 404 <strong>of</strong> 436
(a) means piping that—(i) is connected to a stationary container; and(ii) is used to transfer a hazardous substance into orout <strong>of</strong> <strong>the</strong> stationary container; and(b) includes a process pipeline or a transfer line.The following subclauses are inserted at <strong>the</strong> end <strong>of</strong>regulation 37:(2) If <strong>the</strong> pooling substance is held in a place aboveground in containers each <strong>of</strong> which has a capacity<strong>of</strong> 60 litres or less,—(a) if <strong>the</strong> place‗s total pooling potential is less than20,000 litres, <strong>the</strong> secondary containment systemmust have a capacity <strong>of</strong> at least 25% <strong>of</strong> that totalpooling potential:(b) if <strong>the</strong> place‗s total pooling potential is 20,000 ormore, <strong>the</strong> secondary containment system must havea capacity <strong>of</strong> <strong>the</strong> greater <strong>of</strong>—(i) 5% <strong>of</strong> <strong>the</strong> total pooling potential; or(ii) 5,000 litres.(3) Pooling substances to which subclause (2) applies,must be segregated where appropriate to ensure that<strong>the</strong> leakage <strong>of</strong> one substance may not adverselyaffect <strong>the</strong> container <strong>of</strong> ano<strong>the</strong>r substance.The following subclauses are inserted at <strong>the</strong> end <strong>of</strong>regulation 38:(2) If <strong>the</strong> pooling substance is held in a place above groundin containers one or more <strong>of</strong> which has a capacity <strong>of</strong> morethan 60 litres but none <strong>of</strong> which have a capacity <strong>of</strong> more than450 litres,—(a) if <strong>the</strong> place‗s total pooling potential is less than 20,000litres, <strong>the</strong> secondary containment system must have acapacity <strong>of</strong> ei<strong>the</strong>r 25% <strong>of</strong> that total pooling potential or110% <strong>of</strong> <strong>the</strong> capacity <strong>of</strong> <strong>the</strong> largest container, whichever is<strong>the</strong> greater:(b) if <strong>the</strong> place‗s total pooling potential is 20,000 litres ormore, <strong>the</strong> secondary containment system must have acapacity <strong>of</strong> <strong>the</strong> greater <strong>of</strong>—(i) 5% <strong>of</strong> <strong>the</strong> total pooling potential; or(ii) 5,000 litres.(3) Pooling substances to which subclause (2)applies, must be segregated where appropriate toensure that <strong>the</strong> leakage <strong>of</strong> one substance may notadversely affect <strong>the</strong> container <strong>of</strong> ano<strong>the</strong>r substance.Code EM13 Reg 42 Level 3 emergency management requirements: signageDichlorvos reassessment – application Page 405 <strong>of</strong> 436
<strong>Hazardous</strong> <strong>Substance</strong>s (Identification) Regulations 2001Code I1 Regs 6, 7, 32–35, 36(1) – (7)Code I2Identification requirements, duties <strong>of</strong> persons in charge,accessibility, comprehensibility, clarity and durabilityCode I3 Reg 9 Priority identifiers <strong>for</strong> ecotoxic substancesCode I5 Reg 11 Priority identifiers <strong>for</strong> flammable substancesCode I8 Reg 14 Priority identifiers <strong>for</strong> toxic substancesCode I9 Reg 18 Secondary identifiers <strong>for</strong> all hazardous substancesCode I10 Reg 19 Secondary identifiers <strong>for</strong> corrosive substancesCode I11 Reg 20 Secondary identifiers <strong>for</strong> ecotoxic substancesCode I13 Reg 22 Secondary identifiers <strong>for</strong> flammable substancesCode I16 Reg 25 Secondary identifiers <strong>for</strong> toxic substancesnote:hRegulations 25 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Identification) Regulations 2001If <strong>the</strong> cylinders <strong>of</strong> J72.03 are labelled and marked inaccordance with <strong>the</strong> labelling or marking required by• Land Transport Rule 45001: Dangerous Goods 2005; or• Civil Aviation Rule 92: Carriage <strong>of</strong> Dangerous Goods; or• Maritime Rule 24A: Carriage <strong>of</strong> Cargoes - DangerousGoods;<strong>the</strong>y do not need to comply with <strong>the</strong> secondary identifierrequirements <strong>of</strong> regulations 20 and 25 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong><strong>Substance</strong>s (Identification) Regulations 2001.Code I17 Reg 26 Use <strong>of</strong> generic namesvariation:hChange to Default ControlsRegulations 26 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Identification) Regulations 2001This regulation does not apply to inner packaging <strong>of</strong>J72.03 contained within multiple packaging.Code I18 Reg 27 Requirements <strong>for</strong> using concentration rangesvariation:hChange to Default ControlsRegulations 27 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s(Identification) Regulations 2001This regulation does not apply to inner packaging <strong>of</strong>J72.03 contained within multiple packaging.Code I19 Regs 29 – 31 Additional in<strong>for</strong>mation requirements, including situationswhere substances are in multiple packagingCode I20 Reg 36(8) Durability <strong>of</strong> in<strong>for</strong>mation <strong>for</strong> class 6.1 substancesCode I21 Regs 37- 39,47- 50General documentation requirementsCode I22 Reg 40 Specific documentation requirements <strong>for</strong> corrosive substancesCode I23 Reg 41 Specific documentation requirements <strong>for</strong> ecotoxic substancesCode I25 Reg 43 Specific documentation requirements <strong>for</strong> flammablesubstancesCode I28 Reg 46 Specific documentation requirements <strong>for</strong> toxic substancesDichlorvos reassessment – application Page 406 <strong>of</strong> 436
Code I29 Regs 51, 52 Signage requirementsCode I30 Reg 53 Advertising corrosive and toxic substances<strong>Hazardous</strong> <strong>Substance</strong>s (Tank Wagon and Transportable Containers) Regulations 2004Controls <strong>for</strong> Stationary Container Systems, Secondary Containment and UnintendedIgnition <strong>of</strong> Flammable <strong>Substance</strong>s (GN35A)The controls relating to stationary container systems, secondary containment and unintendedignition <strong>of</strong> flammable substances, as set out in Schedules 8, 9 and 10 respectively <strong>of</strong> <strong>the</strong><strong>Hazardous</strong> <strong>Substance</strong>s (Dangerous Goods and Scheduled Toxic <strong>Substance</strong>s) Transfer Notice2004 (Supplement to <strong>the</strong> New Zealand Gazette, 26 March 2004, No. 35, page 767), asamended, shall apply to this substance, notwithstanding clause 1(1) <strong>of</strong> Schedules 8 and 9 andclause 1 <strong>of</strong> Schedule 10.variation:Schedule 10 <strong>of</strong> <strong>the</strong> <strong>Hazardous</strong> <strong>Substance</strong>s (Dangerous Goods andScheduled Toxic <strong>Substance</strong>s) Transfer Notice 2004f Clause 1 This clause applies as if <strong>the</strong> words ―every class 2 and every class3.1 hazardous substance described in Schedule 1‖ was replaced by:‖this substance‖.Clause 33 This clause applies as if <strong>the</strong> words ―Subject to subclause (2)‖ insubclause (1) were omitted.This clause applies as if subclause (2) were omitted.Table J.3:Additional controls <strong>for</strong> dichlorvosAdditional controls <strong>for</strong> dichlorvos1 Prohibition on use <strong>of</strong> dichlorvos(1) No person may use dichlorvos <strong>for</strong> any purpose o<strong>the</strong>r than—(a) <strong>for</strong> research and development; or(b) as an ingredient or component in <strong>the</strong> manufacture <strong>of</strong> ano<strong>the</strong>r substance orproduct.(2) Despite subclause (1)(a), research and development using dichlorvos does notinclude investigation or experimentation in which <strong>the</strong> substance is discharged,laid or applied in or to <strong>the</strong> outdoor environment.2 Specification <strong>of</strong> pesticide and veterinary medicine actives(1) Any person who—(a) manufactures or imports into New Zealand dichlorvos, which that personhas not previously manufactured or imported on or be<strong>for</strong>e 1 July 2006; or(b) had previously manufactured or imported a hazardous substance listed inTable 1 <strong>of</strong> Schedule 1 on or be<strong>for</strong>e 1 July 2006, but that person has sincemodified <strong>the</strong> manufacturing process or changed <strong>the</strong> source <strong>of</strong> manufacture<strong>for</strong> that hazardous substance, must provide to <strong>the</strong> Authority in writing <strong>the</strong>in<strong>for</strong>mation required by subclauses (3) and (4).(2) The in<strong>for</strong>mation required by subclause (1) must be provided—(a) in <strong>the</strong> case <strong>of</strong> a substance that is manufactured in New Zealand prior tothat substance being sold to ano<strong>the</strong>r person or used in accordance withclause 1 <strong>of</strong> Schedule 3; or(b) in <strong>the</strong> case <strong>of</strong> a substance that is imported into New Zealand, prior to thatsubstance being imported; and(c) in <strong>the</strong> case <strong>of</strong> a substance to which subclause (1)(b) applies—(i) each and every time <strong>the</strong> manufacturing process or source <strong>of</strong>manufacture is changed; and(ii) include equivalent in<strong>for</strong>mation <strong>for</strong> <strong>the</strong> substance that was producedby <strong>the</strong> manufacturing process be<strong>for</strong>e it was modified, or suppliedDichlorvos reassessment – application Page 407 <strong>of</strong> 436
y <strong>the</strong> previous source <strong>of</strong> manufacture, if such in<strong>for</strong>mation has notpreviously been provided to <strong>the</strong> Authority.(3) The in<strong>for</strong>mation to be provided is—(a) <strong>the</strong> name and address <strong>of</strong> <strong>the</strong> manufacturer <strong>of</strong> <strong>the</strong> substance;(b) <strong>the</strong> specification <strong>of</strong> <strong>the</strong> substance including ei<strong>the</strong>r—(i) <strong>the</strong> full name, including relevant citation, <strong>of</strong> <strong>the</strong> national and/orinternational standard(s) set by an international scientific orregulatory body recognised by <strong>the</strong> Authority with which <strong>the</strong>substance complies, and evidence to support this; or (ii) <strong>the</strong>manufacturer‘s specifications including purity <strong>of</strong> <strong>the</strong> hazardoussubstance, isomeric ratio where applicable, maximum impuritycontent and evidence to support <strong>the</strong>se, including details <strong>of</strong>analytical methods used. Where <strong>the</strong> substance is produced at morethan one manufacturing site, this in<strong>for</strong>mation must be provided <strong>for</strong>each site separately;(c) <strong>the</strong> identity <strong>of</strong> any impurity, its origin, and <strong>the</strong> nature <strong>of</strong> its relationship todichlorvos when <strong>the</strong> impurity is present at a concentration <strong>of</strong> 10 g/kg ormore;(d) <strong>the</strong> identity <strong>of</strong> any impurity that is known to be <strong>of</strong> toxicological concern,its origin, and <strong>the</strong> nature <strong>of</strong> its relationship to dichlorvos when <strong>the</strong>impurity is present at a concentration <strong>of</strong> less than 10 g/kg.(4) In<strong>for</strong>mation on an impurity that is required <strong>under</strong> subclause (3) must include—(a) its chemical name;(b) its Chemical Abstract Service Registry number (if available); and(c) its maximum concentration in <strong>the</strong> substance.Table J.4:Additional controls <strong>for</strong> dichlorvos-containing substancesAdditional controls <strong>for</strong> dichlorvos-containing substanaces<strong>Application</strong> Onto or Into Water (b, c, d, e, f, g)The substance may not be applied onto or into water, where water means water in all itsphysical <strong>for</strong>ms, whe<strong>the</strong>r flowing or not, and whe<strong>the</strong>r over or <strong>under</strong> ground, but does notinclude water in any <strong>for</strong>m while in a pipe, tank or cistern.Use Restriction (g)DDVP Insecticide Strip shall only be imported by <strong>the</strong> Ministry <strong>of</strong> Agriculture and Forestry andshall only be used in outdoor insect traps <strong>for</strong> <strong>the</strong> fruit fly surveillance programme.Active Ingredient Concentration Restriction (g)The size <strong>of</strong> each DDVP Insecticide Strip shall be restricted to 2.6 g with a total dichlorvoscontent no greater than 22% by weight.Export-only Restriction (h)Approval <strong>of</strong> J72.03 is limited to manufacture <strong>for</strong> export only..Dichlorvos reassessment – application Page 408 <strong>of</strong> 436
Non-HSNO Act controlsAgricultural Compounds and Veterinary Medicines Act 19971.3 Be<strong>for</strong>e <strong>the</strong>y can be used, <strong>for</strong>mulations meeting <strong>the</strong> definition <strong>of</strong> ―agriculturalcompound‖ <strong>under</strong> <strong>the</strong> Agricultural Compounds and Veterinary Medicines Act 1997,must be approved by <strong>the</strong> Agricultural Compounds and Veterinary Medicines Group(ACVM Group) <strong>of</strong> <strong>the</strong> New Zealand Food Safety Authority. The relevant currentregistrations <strong>for</strong> dichlorvos <strong>for</strong>mulations are:Table J.5:Agricultural Compounds and Veterinary Medicines Group conditions<strong>for</strong> dichlorvos <strong>for</strong>mulationsRegistrationnumberTrade NameDate <strong>of</strong>RegistrationRegistrantP001132 Nuvos 14-03-1968 Orion CropProtection LtdP005877ArmourCrop-Insecticide (DDVP)31-01-2002 BOC LimitedP006080 Divap 07-06-2002 United PhosphorusLtdP007362DDVP InsecticideStrip12-10-2005 Biosecurity NewZealand1.4 The ACVM Group imposes controls (referred to as conditions) on <strong>the</strong> use <strong>of</strong>substances <strong>under</strong> <strong>the</strong> ACVM Act. A set <strong>of</strong> generic conditions are applied (ACVM2010) to substances. Additionally, <strong>the</strong> following specific conditions have been set byACVM Group <strong>for</strong> all dichlorvos <strong>for</strong>mulations.Dichlorvos reassessment – application Page 409 <strong>of</strong> 436
Table J.6:Agricultural Compounds and Veterinary Medicines Group conditions <strong>for</strong>dichlorvos <strong>for</strong>mulationsACVM Conditions and ObligationsCondition 2Condition 3Condition 8DescriptionThe product must be manufactured in accordance with <strong>the</strong>ACVM Standard <strong>for</strong> Good Manufacturing Practice and to <strong>the</strong>chemistry and manufacturing specifications provided by <strong>the</strong>registrant and approved as part <strong>of</strong> <strong>the</strong> registration.Plant Compound: In addition to any labelling, advertising orpromotion requirements specified in <strong>the</strong> current registration,labelling, advertising or promotion <strong>of</strong> <strong>the</strong> product mustcomply with <strong>the</strong> current ACVM - New Zealand Labellingand Advertising Guide <strong>for</strong> Plant Compounds RequiringRegistrationIf <strong>the</strong> product is used on any food producing plant or on oraround any plant not used to produce food:· o<strong>the</strong>r than those specified on <strong>the</strong> current registration; or· in a manner not specified in <strong>the</strong> current registration,<strong>the</strong> user must ensure that residues <strong>of</strong> any substance in <strong>the</strong>product that may occur in plant material produced from <strong>the</strong>plants treated, or in animal material produced from grazing ordirect feeding <strong>of</strong> <strong>the</strong> plants treated to food producing animals,do not exceed <strong>the</strong> lesser <strong>of</strong> ei<strong>the</strong>r:· <strong>the</strong> specified residue limit in <strong>the</strong> current New Zealand(Maximum Residue <strong>of</strong> Agricultural Compounds) FoodStandard and any subsequent amendments; or· <strong>the</strong> default maximum residue limit in <strong>the</strong> current NewZealand (Maximum Residue <strong>of</strong> Agricultural Compounds)Food Standard and any subsequent amendments, when amaximum residue limit <strong>for</strong> that substance has not beenspecified.Condition 37Ongoing obligations:The registrant must provide an annual summary <strong>of</strong> adverseevents to <strong>the</strong> ACVM Group. Adverse events which haveserious implications <strong>for</strong> <strong>the</strong> continued use <strong>of</strong> <strong>the</strong> product mustbe notified immediately.The registrant must also advise <strong>the</strong> ACVM Group <strong>of</strong> any newstudies or data that contradict in<strong>for</strong>mation previouslysupplied.Dichlorvos reassessment – application Page 410 <strong>of</strong> 436
Appendix K: Overseas regulatory actionAustraliaStatusAPVMA review ongoing, latest draft June 2008.Current usesUse% <strong>of</strong> amount usedin Australiastored grain and grain storage structures 55%industrial, commercial and domestic situations. Including abattoirs and meatworks, wineries, food warehouses, mills and empty grain siloshousehold vapour strip products 15%animal housing (dairy cattle sheds, stables, piggeries. Also poultry houses,1.8%although expected to decrease dueto pest resistancegreenhouses (thrips on ornamentals, also tomatoes, cucumbers and capsicums 1.7%26%veterinary products 0.6%Avocado trees <strong>for</strong> leafroller control
Outcome <strong>of</strong> risk assessment <strong>for</strong> <strong>for</strong>mulations with an „equivalent‟ in NewZealand 11 :Product Use Fur<strong>the</strong>r details <strong>of</strong>use50 g/kgaerosolIndoor: Treatment <strong>of</strong>industrial anddomestic premises,stored productfacilities (includingfarm machinery andsilos), greenhouses,farm machinery,storage bins. Alsomushroom housesand in plantfumigation chambers,although <strong>the</strong>se usesare not included on<strong>the</strong> product label. Theproduct is <strong>for</strong>pr<strong>of</strong>essional use only,Outdoor: treatment<strong>of</strong> farm machineryand wasp nests.Operator entersfacility to sprayusing a manualpressure gunFixed installation,which may beoperated remotelyusing a manual orprogrammed timereleaseManual, but remote,treatment <strong>of</strong> grainbins, silos andsimilar sealedstorage containersResult <strong>of</strong>reassessmentMOE exceeded, due toexposure duringtreatment and whenchanging cylindersExposure acceptablewith controls in placeExposure acceptablewith controls in placeExposure acceptablewith controls in placeProposed actionDiscontinue this use,.Maintain use as long asoperator wears elbowlength butyl rubbergloves, chemicalresistant clothing and afull face piecerespirator and doesn‘tenter storage structure<strong>for</strong> 4 days posttreatment(exceptglasshouses <strong>for</strong> whichrestricted entry periodis 4 h).Maintain use as long asoperator wears elbowlength butyl rubbergloves, chemicalresistant clothing and afull face piecerespirator and doesn‘tenter storage structureduring or <strong>for</strong> 4 dayspost-treatment.Maintain use providedoperators wear PPEcomprising elbowlength butyl rubbergloves, chemicalresistant clothing and afull face piecerespirator.1140 & 500g/l ECTreatment <strong>of</strong> grainAutomatic spraying<strong>of</strong> grain onconveyorMOE exceededprimarily duringmixing/loading, sincetreatment <strong>of</strong> grain isautomatic.Discontinue this use.500 g/l EC Surface spray inhousesPr<strong>of</strong>essional useonly, most likely byhand-held sprayer,knapsack sprayer,or a hand wandsupplied via a hosefrom a vehiclemountedspray tankand pump.Exposure from treatingand mixing/loadingeven one house leads toMOE exceedanceDiscontinue this use11 Dual <strong>for</strong>mulations not registered in New Zealand are excluded from this table.Dichlorvos reassessment – application Page 412 <strong>of</strong> 436
Product Use Fur<strong>the</strong>r details <strong>of</strong>useSurface spray in o<strong>the</strong>r Pr<strong>of</strong>essional useindoor situations only, most likely byincluding animal hand-held sprayer,housing, milk and knapsack sprayer,meat processing or a hand wandfacilities,and grain supplied via a hosestorage structures from a vehiclemountedspray tankand pump.Result <strong>of</strong>reassessmentExposure from treatingand mixing/loadingleads to MOEexceedanceProposed actionDiscontinue this useSpace spray, inindoor situationsincluding stables andpiggeries factories,stores, mills, abattoirsand wineries. tobaccostores, warehouses,and glass- andmushroom houses.<strong>Application</strong> ratesvary with location.Operators wouldprobably use a highpressure hand wandin conjunction witha vehicle-mountedspray tank andpump.Exposure from treatingand mixing/loadingleads to MOEexceedanceDiscontinue this useFog or mist stables,piggeries, abattoirs,wineries, factories,stores, mills andwarehouses tobaccostores, warehouses,glass- and mushroomhouses<strong>Application</strong> ratesvary with location.Foggers or mistersmay be portable orstationaryEven with stationaryfoggers/misters,exposure duringmixing/loading is likelyto lead to MOEexceedanceDiscontinue this useSpace spray, fog ormist garbage dumps,beach, picnic andrecreation areasMOE exceeded atexpected work ratesDiscontinue this use inabsence <strong>of</strong> moredetailed in<strong>for</strong>mation onwork rates/exposure.Volatilise from‗wooden boards‘ intobacco stores,warehouses,,glasshouses andmushroom housesUndiluted productis poured ontowooden boards andallowed toevaporateMOE exceeded <strong>for</strong>larger buildingsDiscontinue this use<strong>Application</strong> bywatering can indomestic situationsMOE exceeded atexpected work ratesDiscontinue this use inabsence <strong>of</strong> moredetailed in<strong>for</strong>mation onwork rates/exposure.Use as a liquid baitby mixing with sugarwater<strong>Application</strong> ei<strong>the</strong>rby surface spray orpaint brushMOE exceeded atexpected work ratesDiscontinue this use<strong>Application</strong> to beeand wasp nestsOutdoor applicationusing low-pressurehand wandExposure acceptablewith controls in placeAcceptable if glovesand overalls wornDichlorvos reassessment – application Page 413 <strong>of</strong> 436
Product Use Fur<strong>the</strong>r details <strong>of</strong>use<strong>Application</strong> to Airblast applicationavocado trees (noo<strong>the</strong>r external cropuses are permitted)Result <strong>of</strong>reassessmentMOE exceeded, alsoimpractically sizedbuffer zones to protectaquatic environmentProposed actionDiscontinue this use.Dichlorvos reassessment – application Page 414 <strong>of</strong> 436
Risk assessment identified concernsBystander: Sureguard Pest Strip Household Insecticide approval to be deleted because <strong>of</strong>unacceptable chronic inhalation risk.Operator exposure: Amount <strong>of</strong> dichlorvos that can be safely handled in one day 1.4 kg,even using enclosed mixing systems and gloves and chemical resistant clothing. This is lessthan anticipated amount to be used <strong>for</strong> indoor/outdoor fogging/misting, broadacre applicationto avocado and mechanical application to grain.Environment: only significant oudoor agricultural use is on avocados and this should beterminated due to impractically large (>200 m) buffer zones needed to protect aquatichabitats. Lesser risk due to use on recreational areas outdoors. Require label warnings <strong>of</strong>risks from run-<strong>of</strong>f/wash-<strong>of</strong>f prior to degradation (indoor and outdoor use). Risks to birds andbees expected to be short-lived.Propose:1. Affirm <strong>the</strong> approvals <strong>of</strong> <strong>the</strong> active constituent.2. Due to <strong>the</strong> likelihood <strong>of</strong> toxicologically unacceptable levels <strong>of</strong> operator exposure, delete<strong>the</strong> following uses <strong>of</strong> dichlorvos from product labels:Surface spray.Space spray.Crack and crevice treatment.Pressurised gas in enclosed spaces where <strong>the</strong> operator must enter <strong>the</strong> space<strong>under</strong> fumigation.Portable fogging or misting equipment in enclosed spaces where <strong>the</strong> operatormust enter <strong>the</strong> space <strong>under</strong> fumigation.Watering can.Paintbrush.Outdoor and indoor application by fogging or misting.Broadacre application to avocados.Mechanical application to grain.3. Because <strong>of</strong> a lack <strong>of</strong> in<strong>for</strong>mation on residues 12 (hence an inability to conduct a dietaryintake risk assessment), delete <strong>the</strong> following uses <strong>of</strong> dichlorvos from product labels:<strong>Application</strong> to bagged and stored potatoes<strong>Application</strong> in mushroom houses<strong>Application</strong> in glasshouses and greenhouses except when used <strong>for</strong> ornamentals4. Because <strong>of</strong> <strong>the</strong> likelihood <strong>of</strong> toxicologically unacceptable exposure, include arestraining statement on <strong>the</strong> label instructions to disallow <strong>the</strong> application <strong>of</strong> dichlorvosin buildings that are likely to be re-occupied within four days <strong>of</strong> fumigation, with <strong>the</strong>exception <strong>of</strong> glasshouses and similar plant production facilities.12 Not relevant to an ERMA NZ evaluation <strong>for</strong> reassessmentDichlorvos reassessment – application Page 415 <strong>of</strong> 436
5. Include in label instructions a restricted entry interval <strong>of</strong> 4 hours when dichlorvos isused <strong>for</strong> fumigation <strong>of</strong> glasshouses and similar plant production facilities.6. In order to minimise risk to terrestrial and aquatic species from direct spray or spraydrift and to reduce o<strong>the</strong>r risks to <strong>the</strong> environment from <strong>the</strong> use <strong>of</strong> dichlorvos, includeprecautionary statements on labels indicating risks involved in specific uses.7. Amend product labels to clearly state that dichlorvos is to be used only on stored cerealgrains, since <strong>the</strong> risks <strong>of</strong> human dietary exposure are unknown when dichlorvos isapplied to o<strong>the</strong>r stored grains such as pulses.8. For consistency <strong>of</strong> label instructions across dichlorvos products, amend <strong>the</strong> productlabels describing use on silos or grain silos to specify location <strong>for</strong> use as ‗empty grainsilos‘.9. As a consequence <strong>of</strong> <strong>the</strong> proposed finding <strong>of</strong> <strong>the</strong> review, continued use <strong>of</strong> or any o<strong>the</strong>rdealing with <strong>the</strong> product Sureguard Pest Strip Household Insecticide (APVMA productcode 45596) is likely to have a harmful effect on human beings. The registration <strong>of</strong> thisproduct lapsed, effective from 1 July 2007. Normally a two-year sales period is allowedafter product registrations lapse. The APVMA proposes that, <strong>for</strong> Sureguard Pest StripHousehold Insecticide, <strong>the</strong> two-year sales period will be stopped at <strong>the</strong> finalisation <strong>of</strong><strong>the</strong> review.If <strong>the</strong>se proposals are carried through, <strong>the</strong> remaining use <strong>of</strong> dichlorvos <strong>for</strong>mulations <strong>for</strong> which<strong>the</strong>re is a New Zealand equivalent will be:Manual treatment <strong>of</strong> grain storage containers using 50 g/kg aerosol as long asoperators wear elbow length butyl rubber gloves, chemical resistant clothing and afull face piece respirator and don‘t enter storage structure during treatment or <strong>for</strong> 4days afterwards;Fogging/misting <strong>of</strong> commercial installations such as abattoirs and meat works,wineries, food warehouses, mills and empty grain silos using 50 g/kg aerosols withfixed installation equipment, provided operators wear PPE comprising elbow lengthbutyl rubber gloves, overalls and a half face piece respirator with combined gas/dustcartridge when changing cylinders and provided operators do not enter <strong>the</strong>installation <strong>for</strong> 4 days post-treatment;Fogging/misting <strong>of</strong> commercial glasshouses containing ornamentals using 50 g/kgaerosols with fixed installation equipment, provided operators wear PPE comprisingelbow length butyl rubber gloves, overalls and a half face piece respirator withcombined gas/dust cartridge when changing cylinders and provided operators do notenter <strong>the</strong> installation <strong>for</strong> 4 hours post-treatment;Outdoor use <strong>of</strong> 50 g/kg aerosol to treat farm machinery or wasp nests as long asoperator wears elbow length butyl rubber gloves, chemical resistant clothing and afull face piece respirator;Outdoor use <strong>of</strong> 500 g/l EC to treat bee or wasp nests if gloves and overalls are worn.United StatesStatusUSEPA reregistration eligibility document (RED) completed, July 2006Dichlorvos reassessment – application Page 416 <strong>of</strong> 436
Current usesFormulations:Methods <strong>of</strong> <strong>Application</strong>:Use Sites:Granules <strong>for</strong> bait, liquid, resin impregnated, ready to use spraysand foggers.Applied with ready to use aerosol spray cans, spray equipment,wall mounted foggers, and through slow release fromimpregnated materials, such as resin strips and pet collars.DDVP is registered to control insect pests in agricultural sites,commercial, institutional and industrial sites; in and aroundhomes; and on pets. DDVP is also used in greenhouses; mushroomhouses; storage areas <strong>for</strong> bulk, packaged and bagged raw andprocessed agricultural commodities; foodmanufacturing/processing plants; animal premises; and non-foodareas <strong>of</strong> food-handling establishments. It is also registered <strong>for</strong>direct dermal pour-on treatment <strong>of</strong> cattle and poultry. DDVP is notregistered <strong>for</strong> direct use on any field or greenhouse growncommodities.Use% <strong>of</strong> amount used in UScommodities in bulk storage,54%distribution warehouses and processingplantsLivestock and poultry 28%Pest control operator/structural use 15%In <strong>the</strong> US, continued use is permitted as follows:Fogging glasshouses not containing food commodities.Remote fogging equipment or brush-on coarse spray <strong>of</strong> mushroom houses <strong>under</strong>specified conditions <strong>of</strong> crop development.Remote fogging or misting <strong>of</strong> food-handling establishments (including <strong>the</strong>atres, foodprocessing platns, infustrial plants and warehouses) when not in operation, providedfood is removed and food handling equipment is covered.Crack and crevice spraying in food-handling establishments.Spot treatment by spraying or paint brush and fogging or misting <strong>of</strong> non-food areas<strong>of</strong> food-handling establishments.Localised spraying in bulk food storage or manufacturing areas, provided <strong>the</strong> food isnot directly contaminated.Spraying or fogging <strong>of</strong> farm buildings;Pest strips may be used in animal buildings and milk rooms, provided food andmilking equipment is not contacted directly;Fine spray may be used to treat feed lots, stockyards etc;Specified applications direct to farm animals are permitted;Spray or fogging <strong>of</strong> outdoor public areas is permitted, although not by hand-heldfoggers.Dichlorvos reassessment – application Page 417 <strong>of</strong> 436
For each <strong>of</strong> <strong>the</strong> US permitted uses, application rates are prescribed and PPE is specified asfollows:long-sleeve shirt, long pants, shoes and socks and chemical resistant gloves <strong>for</strong> allapplications except ready to use pest strips and pet flea collars. A respirator mustalso be worn during mixing, loading and application <strong>for</strong> liquid <strong>for</strong>mulations exceptready to use aerosols containing
CanadaStatusPMRA are <strong>under</strong>taking a re-evaluation but details are not available.Current UsesNo in<strong>for</strong>mation available.Outcome <strong>of</strong> risk assessmentLabel changes have been introduced as interim measure to reduce user exposure (PMRA,2008).These changes are intended to do <strong>the</strong> following:1. Implement measures <strong>for</strong> Canadian products that are consistent with measuresvoluntarily adopted in <strong>the</strong> United States.Discontinuation <strong>of</strong> hand-held fogger and crack and crevice applications, andimplementation <strong>of</strong> restricted entry intervals <strong>for</strong> use in mushroom houses.2. Remove uses that are not supported by <strong>the</strong> Canadian technical registrant <strong>for</strong> reevaluationby <strong>the</strong> PMRA.These uses include wineries and wine cellars, surface spray applications in dogkennels, and applications by brush or sprayer <strong>of</strong> a mixed bait to beef cattle,dairy cattle and horses.3. Increase consistency on product labels with respect to <strong>the</strong> personal protective equipment(PPE) required <strong>for</strong> similar application methods.The most restrictive PPE requirements will be adopted <strong>for</strong> all similar products,and PPE label statements will be clarified.Measures <strong>for</strong> <strong>the</strong> domestic products have already been adopted. These include a re<strong>for</strong>mulation<strong>of</strong> <strong>the</strong> pest strip products and changes to use directions that restrict use to areas that aregenerally unoccupied.EUStatusUse <strong>of</strong> dichlorvos as a plant protection product is no longer permitted. Authorisations wereterminated on 6 Dec 2007 and use <strong>of</strong> existing stocks by 6 Dec 2008 (EU, 2007). Use <strong>of</strong>dichlorvos as a biocide is to be reviewed <strong>under</strong> <strong>the</strong> Biocide Directive, but no evaluationdocumentation is available.Dichlorvos reassessment – application Page 419 <strong>of</strong> 436
Current UsesIn <strong>the</strong> past dichlorvos has been approved <strong>for</strong> use in greenhouses to combat aphid, thrips andwhitefly and in cereal and flower bulb storage to combat cereal and flower bulb pests. Priorto termination <strong>of</strong> approval <strong>under</strong> Council Directive 91/414, <strong>the</strong> notifier proposed use only <strong>for</strong>room-treatment <strong>of</strong> flower bulbs during storage. There is no in<strong>for</strong>mation available on use <strong>of</strong>dichlorvos as a biocide.Outcome <strong>of</strong> risk assessmentNotifier <strong>of</strong> dichlorvos <strong>for</strong> plant protection use did not provide adequate in<strong>for</strong>mation toconvince authorities <strong>of</strong> toxicology (concern around mutagenicity in vivo and carcinogenicity)and operator and bystander exposure.Dichlorvos reassessment – application Page 420 <strong>of</strong> 436
Appendix L: Parties consulted during <strong>the</strong> preparation <strong>of</strong> <strong>the</strong>applicationAdria Crop Protection LimitedBayer New Zealand LimitedMAF-BNZBOC New Zealand LimitedFederated Farmers <strong>of</strong> New ZealandFonterraFoundation <strong>of</strong> Arable research (FAR)Greendale MushroomsHorticulture New ZealandMeadows MushroomsNew Zealand Flour Millers AssociationNew Zealand Grain and Seed Trade AssociationNor<strong>the</strong>rn DistributorsNorthland Cymbidium Growers‘ Association IncorporatedOrion Crop Protection LimitedPest Management Association <strong>of</strong> New Zealand (PMANZ)RentokillTe Mata MushroomsZelam LimitedDichlorvos reassessment – application Page 421 <strong>of</strong> 436
Appendix M: ACVM and o<strong>the</strong>r NZFSA administered legislationIn<strong>for</strong>mation supplied by New Zealand Food Safety AuthorityNZFSA1. In September 2008 <strong>the</strong> New Zealand Cabinet agreed that NZFSA‘s mandate is toprotect consumers by providing an effective food regulatory programme that coversfood produced and consumed in New Zealand as well as imported and exported foodproducts. In pursuing this mandate <strong>the</strong> overriding priority will always be to protectconsumers.2. In delivering this mandate, NZFSA is to:engender high levels <strong>of</strong> trust and confidence in <strong>the</strong> New Zealand regulatoryprogramme covering food and related products both domestically andinternationally;base risk management decisions designed to protect consumers on sound scienceand an evidence base, applying precaution when faced with scientificuncertainty;apply <strong>the</strong> principles <strong>of</strong> openness and transparency;engage with stakeholders including consumers and industry sectors;minimise <strong>the</strong> costs <strong>of</strong> regulatory actions/interventions, recognising <strong>the</strong> economicbenefits to domestic and export food businesses and <strong>the</strong> flow-on effects inconsumer food prices;communicate food risks, hygienic practices and nutritional in<strong>for</strong>mation as far as<strong>the</strong>se are known and relevant to <strong>the</strong> food supply and consumer behaviour;recognise that <strong>the</strong>re are New Zealand customs and practices that involve <strong>the</strong>non-commercial hunting, ga<strong>the</strong>ring and/or preparation <strong>of</strong> food where <strong>the</strong> publicdoes not expect regulatory intervention;utilise any capacity to improve business opportunities <strong>for</strong> domestic and exportfocussed food industries;maintain <strong>the</strong> integrity <strong>of</strong> <strong>of</strong>ficial assurances provided to importing countries‘governments; andwork at <strong>the</strong> multilateral and bilateral level to ensure nei<strong>the</strong>r internationalstandards nor importing country standards pose unjustified ‗technical barriers‘ totrade.NZFSA legislative framework3. NZFSA is responsible <strong>for</strong> <strong>the</strong> administration <strong>of</strong> a number <strong>of</strong> acts and regulations.(See Appendix A <strong>for</strong> a list). The paragraphs below provide a brief summary <strong>of</strong> <strong>the</strong>main acts <strong>under</strong> which NZFSA manages risks.Agricultural Compounds and Veterinary Medicines Act 19974. The purpose <strong>of</strong> <strong>the</strong> ACVM Act is to prevent or manage specific risks associated with<strong>the</strong> use <strong>of</strong> agricultural compounds, <strong>the</strong> definition <strong>of</strong> which includes veterinarymedicines, and to ensure that <strong>the</strong>ir use does not result in breaches <strong>of</strong> domestic foodresidue standards.Dichlorvos reassessment – application Page 422 <strong>of</strong> 436
Animal Products Act 19995. The purpose <strong>of</strong> this Act is to minimise and manage risks to human or animal healtharising from <strong>the</strong> production and processing <strong>of</strong> animal material and to facilitate <strong>the</strong>entry <strong>of</strong> animal material and products into overseas markets. This purpose isachieved by instituting measures and controls that ensure so far as is practicable thatall traded animal products are fit <strong>for</strong> <strong>the</strong>ir intended purpose.6. Under <strong>the</strong> act, NZFSA is responsible <strong>for</strong> setting and ensuring compliance withstandards <strong>for</strong> <strong>the</strong> primary processing and export <strong>of</strong> animal products including meat,game, seafood, dairy and honey.Food Act 19817. The purpose <strong>of</strong> this Act is to manage food safety risk factors inherent in <strong>the</strong>production, manufacture, preparation, packaging, storage, handling, transport,distribution, or sale <strong>of</strong> food that is intended <strong>for</strong> human consumption.8. The Act also provides <strong>for</strong> <strong>the</strong> setting <strong>of</strong> and monitoring <strong>of</strong> Maximum Residue Limits(MRLs) <strong>for</strong> agricultural chemicals and veterinary medicines to ensure GoodAgricultural Practice (GAP) is complied with in <strong>the</strong>ir use and to safeguard consumerhealth. The Act‘s provisions apply to both domestic and imported food.Wine Act 20039. This Act covers all types <strong>of</strong> wine (grape, fruit and vegetable wine), cider and mead.The purpose <strong>of</strong> <strong>the</strong> Act is:to set standards <strong>for</strong> identity, truth in labelling, and <strong>the</strong> safety <strong>of</strong> wine;to minimise and manage <strong>the</strong> risks to human health arising from <strong>the</strong> making <strong>of</strong>wine and to ensure compliance with wine standards;to facilitate <strong>the</strong> entry <strong>of</strong> wine into overseas markets by providing <strong>the</strong> controlsand mechanisms needed to give and safeguard <strong>of</strong>ficial assurances issued <strong>for</strong> <strong>the</strong>purpose <strong>of</strong> enabling entry into those markets;to enable <strong>the</strong> setting <strong>of</strong> export eligibility requirements to safeguard <strong>the</strong> reputation<strong>of</strong> New Zealand wine in overseas markets.Government agencies‟ areas <strong>of</strong> responsibility in risk management10. Government policy provides <strong>the</strong> direction <strong>for</strong> managing risks posed by any substancethat could potentially cause adverse effects. Because <strong>of</strong> <strong>the</strong> need <strong>for</strong> specialistknowledge to deal with particular risks, <strong>the</strong> management <strong>of</strong> risk areas has beenplaced with different government ministries and departments, with <strong>the</strong> expectation <strong>of</strong>close cooperation in areas that unavoidably overlap.11. The areas <strong>of</strong> responsibility, relevant legislation, and <strong>the</strong> responsible governmentdepartment in New Zealand are:AREA OFRESPONSIBILITYPreventing <strong>the</strong>introduction <strong>of</strong>,eradicating or controllingpests and unwantedRELEVANTLEGISLATIONBiosecurity Act1993RESPONSIBLEAGENCYBiosecurityAuthorityDichlorvos reassessment – application Page 423 <strong>of</strong> 436
organismsProviding generalassessment and imposingcontrol on hazardoussubstances*Protecting <strong>the</strong> generalpublic and <strong>the</strong>environment fromhazardous substances ornew organismsProtecting animal welfareAssurances <strong>for</strong> <strong>the</strong> safety<strong>of</strong> export primary produce,food and food-relatedproductsAssurances <strong>for</strong> <strong>the</strong> safetyand suitability <strong>of</strong> domesticfood and food-relatedproductsManaging risks to publichealth, animal welfare,agricultural security, tradefrom use <strong>of</strong> agriculturalcompoundsControlling hazards in <strong>the</strong>workplaceControlling medicines anddrugs<strong>Hazardous</strong><strong>Substance</strong>s andNew OrganismsAct 1996ResourceManagement Act1991Animal WelfareAct 1999Animal ProductsAct 1999Animal ProductsAct 1999 Food Act1981AgriculturalCompounds andVeterinaryMedicines Act 1997Health and Safetyin Employment Act1992Medicines Act 1981Misuse <strong>of</strong> DrugsAct 1975Ministry <strong>for</strong> <strong>the</strong>Environment,Environmental RiskManagementAuthorityMinistry <strong>for</strong> <strong>the</strong>Environment andTerritorial LocalAuthoritiesBiosecurityAuthorityNZ Food SafetyAuthorityNZ Food SafetyAuthorityNZ Food SafetyAuthority, ACVMGroupDepartment <strong>of</strong>Labour,Occupational Safetyand Health ServicesMinistry <strong>of</strong> Health,NZ Medicines andMedical DevicesSafety Authority12. Collectively, all <strong>of</strong> <strong>the</strong> laws mentioned above <strong>for</strong>m <strong>the</strong> statutory basis <strong>for</strong> regulatorycontrol <strong>of</strong> substances in New Zealand. In all <strong>of</strong> <strong>the</strong>se areas Government policy isbased on <strong>the</strong> principles <strong>of</strong>:regulatory intervention only when it is necessary; andestablishing acceptable levels <strong>of</strong> protection from adverse effects.ACVM regulatory framework and government policy13. Adverse effects resulting from <strong>the</strong> use and/or misuse <strong>of</strong> agricultural compounds have<strong>the</strong> potential to cause serious problems in areas ranging from human health tointernational trade. Consequently, <strong>the</strong>se products are subject to strict regulatorycontrols on <strong>the</strong>ir importation, manufacture, sale and use.Dichlorvos reassessment – application Page 424 <strong>of</strong> 436
14. Regulatory control <strong>of</strong> <strong>the</strong>se products focuses on avoiding or minimising <strong>the</strong> possibleadverse effects that may result from <strong>the</strong>ir use. Because <strong>of</strong> <strong>the</strong> wide range <strong>of</strong> productsand substances that are classified as agricultural compounds, <strong>the</strong> adverse effectscould be any or all <strong>of</strong> <strong>the</strong> following:harm to persons using or exposed to <strong>the</strong> compoundsharm to <strong>the</strong> health and welfare <strong>of</strong> animals treated or exposedharm to <strong>the</strong> environment in its broadest senseunacceptable primary produce <strong>for</strong> both <strong>the</strong> local and export marketunacceptable residues in foods or pharmaceutical productsintroduction <strong>of</strong> pests or unwanted organisms, or interference in pest controlprogrammes.15. The New Zealand Government has created a regulatory framework designed tomanage <strong>the</strong> risks <strong>of</strong> <strong>the</strong>se adverse effects. The framework includes statutory andnon-statutory mechanisms to control substances, products, and <strong>the</strong>ir use.16. The basic Government policy is to impose regulatory control that is ‗necessary andsufficient‘ to manage <strong>the</strong> risks down to acceptable levels, while avoiding unnecessarycosts <strong>of</strong> compliance to New Zealand as a whole. The policy has a broad focusincluding:domestic food safetytrade in primary produce and processed foods, food-related products andpharmaceuticals to meet importing country safety requirementsanimal welfareprotection from <strong>the</strong> introduction <strong>of</strong> pests and unwanted organismsprotection <strong>of</strong> <strong>the</strong> environmentgeneral public health and safetyhealth and safety in <strong>the</strong> workplace.Operation <strong>of</strong> <strong>the</strong> ACVM Act17. The ACVM Act regulates substances used in <strong>the</strong> management <strong>of</strong> plants and animals,including agricultural chemicals, fertilisers, stock food, pet food and veterinarymedicines and <strong>the</strong> term ‗agricultural compound‘ includes all <strong>the</strong>se aspects within itsdefinition. The specific risks managed <strong>under</strong> <strong>the</strong> ACVM Act are:risks to public health;risks to trade in primary produce;risks to animal welfare; andrisks to agricultural security.18. The ACVM Group has established thresholds and criteria <strong>for</strong> <strong>the</strong>se risk areas. This<strong>for</strong>ms <strong>the</strong> basis <strong>for</strong> determining <strong>the</strong> level <strong>of</strong> regulatory oversight <strong>of</strong> agriculturalcompounds and <strong>the</strong> in<strong>for</strong>mation requirements required to support an application <strong>for</strong>registration.19. The Act seeks to achieve its purpose by providing that no agricultural compoundmay be used in New Zealand unless that use is authorised by or <strong>under</strong> this Act. Themechanisms <strong>for</strong> authorisation are:Dichlorvos reassessment – application Page 425 <strong>of</strong> 436
egistration subject to conditions; orexempt from registration where <strong>the</strong> substance is generally recognised as safe; orapprove an agricultural compound without registration <strong>under</strong> specialcircumstances; orexemption from <strong>the</strong> requirement to register subject to prescribed conditions.20. The Act provides several mechanisms <strong>for</strong> managing <strong>the</strong> risks <strong>of</strong> <strong>the</strong> product. Theseinclude:a wide range <strong>of</strong> conditions <strong>of</strong> registration can be applied to products requiringregistration or exempt from registration. For example, <strong>the</strong>y can place conditionson importation, manufacture, labelling, packaging, storage, who can sell or use.Limit <strong>the</strong> term <strong>of</strong> registrationApproval <strong>of</strong> operating plansRecognition <strong>of</strong> persons21. Registration <strong>of</strong> products (or Trade Name Products) requires <strong>the</strong> applicant to submitin<strong>for</strong>mation in a range <strong>of</strong> areas so ACVM Group can determine any risks <strong>of</strong> <strong>the</strong>product. The main in<strong>for</strong>mation requirements are:chemistry and manufacturingefficacytarget animal (or crop) safetyresiduesalong with a copy <strong>of</strong> <strong>the</strong> label.22. Once <strong>the</strong> in<strong>for</strong>mation has been assessed, <strong>the</strong> risks determined, <strong>the</strong> ACVM Groupconsiders what conditions <strong>of</strong> registration are required to ensure any risks areadequately managed. In considering this, <strong>the</strong> ACVM Group is also obliged toconsider whe<strong>the</strong>r any o<strong>the</strong>r legislation can provide <strong>the</strong>se controls.23. The ACVM Group maintains a public register on its website <strong>of</strong> all registeredproducts. The register contains basic in<strong>for</strong>mation on <strong>the</strong> product and a crossreference to a scanned version <strong>of</strong> <strong>the</strong> label content.24. An important issue to remember is that some <strong>of</strong> New Zealand‘s trading partners havebanned <strong>the</strong> use <strong>of</strong> certain substances in food-producing animals. The ACVM Groupholds a list <strong>of</strong> <strong>the</strong>se substances and, if unsure <strong>of</strong> <strong>the</strong> status <strong>of</strong> <strong>the</strong> substance to beused, users must check with <strong>the</strong> ACVM Group prior to any <strong>of</strong>f-label use.ACVM Act relationship with o<strong>the</strong>r NZFSA-administeredlegislation25. There is a complex technical relationship between <strong>the</strong> ACVM Act and o<strong>the</strong>r Actsadministered by NZFSA (and also <strong>the</strong> Biosecurity Act, Animal Welfare Act,Medicines Act and <strong>Hazardous</strong> <strong>Substance</strong>s Act which are administered by o<strong>the</strong>ragencies).26. The Food Act, <strong>the</strong> Animal Products Act and <strong>the</strong> Wine Act provide required outcomes<strong>for</strong> <strong>the</strong> protection <strong>of</strong> human health and safety in relation to food and food-relatedproducts. Standards <strong>for</strong> <strong>the</strong> management <strong>of</strong> risks to <strong>the</strong> safety and integrity <strong>of</strong> NewDichlorvos reassessment – application Page 426 <strong>of</strong> 436
Zealand‘s trade in primary produce and <strong>for</strong> <strong>of</strong>ficial assurances/certification areprovided by <strong>the</strong> Animal Products Act and <strong>the</strong> Wine Act.27. The ACVM Act is designed to provide a ―one stop shop‖ <strong>for</strong> <strong>the</strong> assessment andmanagement <strong>of</strong> those risks as <strong>the</strong>y relate to <strong>the</strong> use <strong>of</strong> agricultural compound andveterinary medicines.Food standards <strong>under</strong> <strong>the</strong> Food Act 198128. In New Zealand, MRLs are set <strong>under</strong> <strong>the</strong> Food Act as food standards, namely <strong>the</strong>New Zealand (Maximum Residue Limits <strong>of</strong> Agricultural Compounds) FoodStandards. These Standards are amended a number <strong>of</strong> times each year to reflectchanges in <strong>the</strong> use <strong>of</strong> agricultural compounds in <strong>the</strong> production <strong>of</strong> food.29. MRLs indicate <strong>the</strong> maximum legal levels at which residues <strong>of</strong> agriculturalcompounds and veterinary medicines may be present in food <strong>for</strong> sale in NewZealand.30. MRLs are primarily a tool <strong>for</strong> monitoring <strong>the</strong> use <strong>of</strong> agricultural compounds againstgood agricultural practice (GAP). GAP is not explicitly defined or regulated, but is<strong>the</strong> generally-accepted means <strong>of</strong> producing safe primary produce. GAP is aboutensuring that chemical residues in food are as low as practicable, withoutcompromising <strong>the</strong> ability <strong>of</strong> <strong>the</strong> chemical to successfully do what is intended.31. The MRL Standards are issued by <strong>the</strong> Minister <strong>for</strong> Food Safety <strong>under</strong> Section 11C <strong>of</strong><strong>the</strong> Food Act 1981. The MRL Standards have been amended regularly since 1999,when it became <strong>the</strong> base standard <strong>for</strong> agricultural compound residues in foods as aparallel standard with regulation 257 <strong>of</strong> <strong>the</strong> Food Regulations 1984, which have sincebeen revoked. The frequency <strong>of</strong> <strong>the</strong>se amendments reflects new agriculturalcompounds coming on <strong>the</strong> market and changes in <strong>the</strong> registered uses <strong>of</strong> compoundsalready available.32. NZFSA administers <strong>the</strong> MRL Standards but <strong>the</strong> final decision on any changes to <strong>the</strong>Standards rests with <strong>the</strong> Minister <strong>for</strong> Food Safety. When amending or issuing anyfood standard, including <strong>the</strong> MRL Standards, <strong>the</strong> Minister must take into account <strong>the</strong>following:<strong>the</strong> need to protect public health;<strong>the</strong> desirability <strong>of</strong> avoiding unnecessary restrictions on trade;<strong>the</strong> desirability <strong>of</strong> maintaining consistency between New Zealand's foodstandards and those applying internationally;New Zealand's obligations <strong>under</strong> any relevant international treaty,agreement, convention, or protocol, and, in particular, <strong>under</strong> <strong>the</strong>Australia-New Zealand Joint Food Standards Agreement; andsuch o<strong>the</strong>r matters as <strong>the</strong> Minister considers appropriate.33. In most instances, MRLs are recommended based on <strong>the</strong> assessment <strong>of</strong> <strong>the</strong> productcontaining <strong>the</strong> active ingredient <strong>under</strong> <strong>the</strong> ACVM Act. Under this Act, GAP isestablished and <strong>the</strong> residue assessment based on this GAP determines <strong>the</strong> likelyresidues in food and feed crops. Ano<strong>the</strong>r important consideration is whe<strong>the</strong>r <strong>the</strong>reare any trade issues that requiring addressing with respect to residues and setting <strong>of</strong>MRLs. This in<strong>for</strong>mation <strong>for</strong>ms <strong>the</strong> basis <strong>for</strong> setting MRLs in <strong>the</strong> New Zealand(Maximum Residue Limits <strong>of</strong> Agricultural Compounds) Food Standards.Dichlorvos reassessment – application Page 427 <strong>of</strong> 436
34. The MRLs vary from country to country depending on <strong>the</strong> pesticides available, <strong>the</strong>crops being treated and <strong>the</strong> way <strong>the</strong> pesticides are used. Food exporters must complywith <strong>the</strong>se MRLs as a condition <strong>of</strong> market access. To help New Zealand exportersmeet <strong>the</strong>se market access requirements, NSFSA maintains a database <strong>of</strong> nationalpesticide MRLs from around <strong>the</strong> world that are relevant to New Zealand foodexporters.Animal Products Act 199935. The Animal Products Act provides <strong>for</strong> <strong>the</strong> setting <strong>of</strong> standards that must be met byanimal products in relation to, inter alia, composition <strong>of</strong> animal material or products;limitations or requirements in relation to ingredients or additives; microbiological orchemical status.36. The Act also provides <strong>for</strong> <strong>the</strong> specifying <strong>of</strong> requirements that must be met by animalproducts <strong>for</strong> <strong>the</strong>m to be eligible <strong>for</strong> export and <strong>for</strong> requirements and systems thatsafeguard <strong>of</strong>ficial assurances provided by New Zealand in respect <strong>of</strong> those products.37. The ACVM Act provides a mechanism to ensure animal produce complies with <strong>the</strong>Animal Products Act requirements. Mechanisms include restricting who canauthorise to use, or sell or use products, and setting <strong>of</strong> withholding periods to ensureresidues comply with Maximum Permissible Residues in <strong>the</strong> Animal Products Act.Wine Act 200338. The Wine Act 2003 provides <strong>for</strong> <strong>the</strong> setting <strong>of</strong> standards to allow <strong>the</strong> management <strong>of</strong>risks to human health arising from <strong>the</strong> making <strong>of</strong> wine in order to ensure that <strong>the</strong>wine is fit <strong>for</strong> its purpose.39. Under <strong>the</strong> ACVM Act, <strong>the</strong> main mechanism to complement <strong>the</strong> Wine Act is byensuring <strong>the</strong> use <strong>of</strong> <strong>the</strong> agricultural compound in grape production will comply withMRLs.NZFSA verification and monitoring programmesImplementation <strong>of</strong> control measures40. Industry working throughout <strong>the</strong> food chain has <strong>the</strong> primary role in implementation<strong>of</strong> control measures. Never<strong>the</strong>less, NZFSA may be directly involved in this step in<strong>the</strong> Risk Management Framework (RMF), such as in supervisory meat inspection.More <strong>of</strong>ten, <strong>the</strong> Verification Agency <strong>of</strong> NZFSA will verify control measuresimplemented by industry. The Compliance Group <strong>of</strong> NZFSA carries out anindependent audit <strong>of</strong> regulatory functions and applies sanctions where controlmeasures have not been properly implemented by industry.41. The Approvals and ACVM Group <strong>of</strong> NZFSA also carries out an implementationfunction by registering food premises and approving food safety plans developed byindustry.42. NZFSA <strong>of</strong>ten develops implementation tools to assist stakeholders in implementingregulatory requirements. Examples are generic codes <strong>of</strong> hygienic practice <strong>for</strong>different food commodities, guidelines on quality assurance systems, accreditationsystems <strong>for</strong> laboratories, and assisting with training and education.Verification programmes43. The NZFSA Verification Agency (NZFSA VA) verifies that food safety programmesare adhered to at premises where meat, seafood and o<strong>the</strong>r animal products areDichlorvos reassessment – application Page 428 <strong>of</strong> 436
processed and stored. It employs veterinarians to inspect animals, ensure animalwelfare protocols are followed and provides export certification to <strong>the</strong> products.44. NZFSA VA verifies that meat, seafood and o<strong>the</strong>r animal products and by-productsmeet both <strong>the</strong> New Zealand standards and additional standards <strong>of</strong> importingcountries.Monitoring <strong>of</strong> <strong>the</strong> food chain by NZFSA45. The aim <strong>of</strong> monitoring by NZFSA is to ga<strong>the</strong>r and analyse data on <strong>the</strong> level <strong>of</strong>control <strong>of</strong> specific hazards throughout <strong>the</strong> food chain and combine this with humanhealth surveillance data to determine <strong>the</strong> effectiveness <strong>of</strong> regulatory activities. Thismay be carried out ahead <strong>of</strong> implementation <strong>of</strong> control measures so as to establishbaseline levels or it may follow <strong>the</strong>ir implementation. Monitoring programmescarried out by NZFSA include.National Microbiological Database <strong>for</strong> systematic and ongoing monitoring <strong>of</strong>premises slaughtering cattle, sheep, deer, goats, poultry and ostriches.Food Residue Surveillance Programme <strong>for</strong> compliance with chemical foodsafety standards across a wide range <strong>of</strong> foods.Total Diet Survey <strong>for</strong> evaluating <strong>the</strong> level <strong>of</strong> exposure <strong>of</strong> <strong>the</strong> New Zealandpopulation to chemicals in <strong>the</strong> food supply.National Residue Monitoring Programme <strong>for</strong> providing food safety assuranceson all animal products, including farmed and wild animals, fish and honey.NZFSA role in trade46. Government policy <strong>for</strong> food safety is developed from a New Zealand perspective, butit is influenced by international and bilateral obligations as well. These externalfactors include agreements and treaties between New Zealand and particularcountries to facilitate trade, harmonise assurance and compliance activities, andfacilitate <strong>the</strong> movement <strong>of</strong> people and goods. They also include multinationalstandards established by organisations such as <strong>the</strong> World Health Organization(WHO), Office International de Epizooties (OIE), World Trade Organization (WTO),and <strong>the</strong> Organization <strong>for</strong> Economic Cooperation and Development (OECD).47. Much <strong>of</strong> <strong>the</strong> work done by NZFSA involves negotiations with New Zealand‘s tradingpartners and plays a key role in gaining market access <strong>for</strong> New Zealand products.NZFSA works to secure market access at various levels. For example, at <strong>the</strong>multilateral level, NZFSA works with a number <strong>of</strong> international bodies. Some <strong>of</strong><strong>the</strong>se are:Codex Alimentarius Commission is an international body set up <strong>under</strong> <strong>the</strong>auspices <strong>of</strong> <strong>the</strong> United Nations Food and Agriculture Organization (FAO) andWHO) and charged with developing a global food code. It develops foodstandards, guidelines and related texts such as codes <strong>of</strong> practice <strong>under</strong> <strong>the</strong> JointFAO/WHO Food Standards Programme. The main purposes <strong>of</strong> this Programmeare protecting health <strong>of</strong> <strong>the</strong> consumers and ensuring fair practices in <strong>the</strong> foodtrade, and promoting coordination <strong>of</strong> all food standards work <strong>under</strong>taken byinternational governmental and non-governmental organisations.Organisation Mondiale de la Santé Animale (OIE), whose focus is <strong>the</strong> reduction<strong>of</strong> food borne risks to human health due to hazards arising from animalproduction. NZFSA is represented on <strong>the</strong> permanent Working Group on AnimalDichlorvos reassessment – application Page 429 <strong>of</strong> 436
Production Food Safety (APFSWG) which coordinates <strong>the</strong> food safety activities<strong>of</strong> <strong>the</strong> OIE.International Plant Protection Convention (IPPC). New Zealand is a contractingparty to this treaty which aims to secure action to prevent <strong>the</strong> spread andintroduction <strong>of</strong> pests <strong>of</strong> plants and plant products, and to promote appropriatemeasures <strong>for</strong> <strong>the</strong>ir control. It is governed by <strong>the</strong> Commission on PhytosanitaryMeasures (CPM) which adopts International Standards <strong>for</strong> PhytosanitaryMeasures (ISPM).48. NZFSA‘s participation in <strong>the</strong>se organisations focuses on ensuring that <strong>the</strong>ir rules arescience and risk-based and reflect New Zealand‘s needs.Bilateral agreements49. Bilateral arrangements are negotiated with importing countries, <strong>the</strong> aim being toalign standards or have a trading partner accept that New Zealand systems deliverresults that meet <strong>the</strong>ir requirements. NZFSA market access experts work to find <strong>the</strong>best ways to meet importing requirements that are cost-effective and flexible <strong>for</strong> ourindustry.50. The Agreement on mutual recognition in relation to con<strong>for</strong>mity assessments between<strong>the</strong> European Community (EC) and New Zealand (98/509/EC) covers all medicinalproducts which are industrially manufactured in New Zealand and <strong>the</strong> EC and towhich Good Manufacturing Practice (GMP) requirements apply. (Medicinalproducts include all human and veterinary products).NZFSA principles <strong>for</strong> risk assessment51. Food safety is an accepted consumer requirement but one that courts controversy.The last decade has seen vastly increased knowledge on risks to consumersassociated with biological, chemical and physical hazards in <strong>the</strong> food chain, alongwith demonstrated success in <strong>the</strong> application <strong>of</strong> new regulatory systems and foodsafety programmes. Never<strong>the</strong>less, foodborne illness continue to be a significantproblem in all countries and governments are responding in a number <strong>of</strong> ways toassure <strong>the</strong> safety <strong>of</strong> food provided to domestic consumers and to those in <strong>of</strong>fshoremarkets.52. NZFSA also has a mandate to improve business opportunities wherever practicable.This is driving closer cooperation between NZFSA and industry in identifyingpriority areas <strong>for</strong> applied research and regulatory change so as to accommodateinnovative and cost-effective technologies. Government promotion <strong>of</strong> economic,environmental and social sustainability (non-harmonised <strong>under</strong> international foodtrade agreements) also influences NZFSA domestic regulatory policies.53. NZFSA, in common with a number <strong>of</strong> o<strong>the</strong>r food safety regulators, uses risk analysisto answer a basic set <strong>of</strong> questions:What can go wrong?How likely is it to go wrong?How serious would it be if it went wrong?What can be done to reduce <strong>the</strong> likelihood and/or seriousness <strong>of</strong> it going wrong?54. During risk assessment, scientific judgements <strong>of</strong>ten entail a choice among severalreasonable options. Uncertainty is intrinsic to risk analysis and different approachesDichlorvos reassessment – application Page 430 <strong>of</strong> 436
may be taken to risk management in <strong>the</strong> face <strong>of</strong> scientific uncertainty in differentpolitical, social and economic contexts.55. In some cases, consumer fears have driven actual bans on trade even though this wasnot scientifically supported by international standard-setting processes (eg EuropeanUnion ban on importation <strong>of</strong> hormone-treated beef from all countries including NewZealand). In o<strong>the</strong>r cases, a conservative approach to standard setting may be takenby NZFSA if <strong>the</strong> ramifications <strong>of</strong> a single detection <strong>of</strong> a high-pr<strong>of</strong>ile pathogen (eg E.coli O157: H7) in exported product might include a worst-case reaction from tradingpartners.56. NZFSA does not have a specific policy on application <strong>of</strong> a precautionary approach in<strong>the</strong> face <strong>of</strong> scientific uncertainty. Ra<strong>the</strong>r, <strong>the</strong>re is an <strong>under</strong>standing that incorporation<strong>of</strong> precaution in <strong>the</strong> RMF will be rational, practical and based on scientific principles.If <strong>the</strong>re is likely to be a significant risk to human health from a particular hazard orsituation, NZFSA will take appropriate risk management action that is proportionalto: <strong>the</strong> potential risk, <strong>the</strong> consequences <strong>of</strong> <strong>the</strong> risk management option(s) chosen, and<strong>the</strong> degree <strong>of</strong> uncertainty in <strong>the</strong> scientific evaluation.57. The regulatory response to a risk by NZFSA will prevent or limit exposure whilemore conclusive in<strong>for</strong>mation is gained on <strong>the</strong> actual risks faced and <strong>the</strong> controlmeasures that are likely to be most effective. For products in trade, <strong>the</strong>re is anobligation <strong>under</strong> <strong>the</strong> WTO SPS Agreement to actively pursue additional scientificin<strong>for</strong>mation when a precautionary approach is taken, with timely review <strong>of</strong> interimcontrol measures.58. As a signatory to <strong>the</strong> World Trade Organization Agreement on <strong>the</strong> <strong>Application</strong> <strong>of</strong>Sanitary and Phytosanitary Measures (WTO SPS Agreement), New Zealand isacutely aware <strong>of</strong> its responsibilities in pursuing a risk-based and equitableinternational trading environment. Consequently, NZFSA has developed acomprehensive strategy <strong>for</strong> incorporating <strong>the</strong> risk analysis guidelines developed by<strong>the</strong> Codex Alimentarius Commission (CAC) in its regulatory systems whereverappropriate.59. In imported food situations, <strong>the</strong> WTO SPS Agreement places specific constraints onfactors that can be included in decisions on ‗appropriate levels <strong>of</strong> protection‘ (ALOP)that are chosen by NZFSA. Decisions should take into account <strong>the</strong> minimisation <strong>of</strong>trade effects and ensure that selected control measures are not more restrictive thannecessary to meet an ALOP. NZFSA must also avoid unjustifiable or arbitrarydistinctions in levels <strong>of</strong> ALOP chosen in different food safety situations.Dichlorvos60. There are currently four products registered <strong>under</strong> <strong>the</strong> ACVM Act that containdichlorvos:ArmourCrop-Insecticide, registration number P5877; andDDVP Insecticide Strip, registration number P7362; andDivap, registration number P6080; andNuvos, registration number P113261. Divap and Nuvos are agricultural chemical trade name products with claims <strong>for</strong> useon a range <strong>of</strong> agricultural and horticultural crops and public health uses.62. ArmourCrop-Insecticide is an agricultural chemical trade name product with a claim<strong>for</strong> use on pepper crop.63. DDVP Insecticide Strip is an agricultural chemical trade name product with a claim<strong>for</strong> fruit fly surveillance.Dichlorvos reassessment – application Page 431 <strong>of</strong> 436
64. Based on a Joint meeting <strong>of</strong> <strong>the</strong> FAO Working <strong>of</strong> Experts on Pesticide Residues and<strong>the</strong> WHO Expert Committee on Pesticide Residues Acceptable Daily Intake (JMPRADI) <strong>of</strong> 0.004 mg/kgbw/day <strong>the</strong> dietary burden <strong>of</strong> dichlorvos in adults is equivalentto 93% <strong>of</strong> <strong>the</strong> ADI.65. Current controls on <strong>the</strong> products are consistent with <strong>the</strong> majority <strong>of</strong> o<strong>the</strong>r agriculturalchemical trade name products registered <strong>under</strong> <strong>the</strong> ACVM Act. Withholding periodsto avoid non-compliant residues are set and stated on <strong>the</strong> labels <strong>for</strong> <strong>the</strong> approveduses. There is no obligation to comply with <strong>the</strong> stated withholding periods. However,<strong>the</strong>re is a statutory obligation to ensure that any residues in produce from treatedanimals or crops comply with relevant residue limits.Dichlorvos reassessment – application Page 432 <strong>of</strong> 436
Appendix A• Agricultural Compounds and Veterinary Medicines Act Commencement Order 2001 SR2001/100• Agricultural Compounds and Veterinary Medicines (Fees and Charges) Regulations 2002• Agricultural Compounds and Veterinary Medicines (Transitional Provisions) Regulations 2002• Agricultural Compounds and Veterinary Medicines Regulations 2001 SR 2001/101• Agricultural Compounds and Veterinary Medicines Act 1997• Animal Products Act 1999• Animal Products Amendment Act 2002• Animal Products (Ancillary and Transitional Provisions) Amendment Act 2002• Animal Products (Ancillary and Transitional Provisions) Amendment Act 2005• Animal Products (Regulated Control Scheme Bivalve Molluscan Shellfish) Regulations 2006• Animal Products (Regulated Control Scheme - Contaminant Monitoring and Surveillance)Regulations 2004• Animal Products Regulations 2000• Animal Products (Fees, Charges, and Levies) Regulations 2007 dated 1 July 2007• Animal Products (Regulated Control Scheme--Limited Processing Fishing Vessels) Regulations2001• Animal Products (Regulated Control Scheme-Dairy Export Quota Products) Regulations 2008• Dairy Industry Restructuring (Transfer <strong>of</strong> Export Licences)• Animal Products (Dairy) Regulations 2005• Animal Products (Dairy Industry Fees and Charges) Regulations 2007• Animal Products (Exemptions and Inclusions) Order 2000• Dairy Industry (National Residue Monitoring Programme) Regulations 2002• Food Act 1981• Food Hygiene Regulations 1974• Food (Safety) Regulations 2002• Australia New Zealand Food Standards Code• New Zealand (Maximum Residue Limits <strong>of</strong> Agricultural Compounds) Food Standards 2004• New Zealand (Milk and Milk Products Processing) Food Standards 2002• Wine Act 2003Dichlorvos reassessment – application Page 433 <strong>of</strong> 436
Appendix N: Plant & Food Research Report on UseDichlorvos reassessment – application Page 434 <strong>of</strong> 436
Appendix O: ReferencesACVM (2010) http://www.nzfsa.govt.nz/acvm/publications/in<strong>for</strong>mation-papers/new-registrationconditions-<strong>for</strong>-agricultural-chemicals-0210.htm#P51_7319(retrieved 29 July 2010).APVMA (2008) Dichlorvos – Preliminary Review Findings Report.Barrett KL, Campbell PJ, Candolfi MP, Forster R, Grandy N, Harrison EG, Hassan S, Huet MC,Lewis G, Oomen P, Schmuck R, Voght H. (2000) Guidance document on regulatory testing on riskassessment procedures <strong>for</strong> plant protection products with non-target arthropods. From ESCORT 2Workshop SETAC-Europe.EFSA (2008). Risk assessment to birds and mammals, The EFSA Journal (2008) 734:1-181ERMA New Zealand 2008a. User Guide to HSNO Thresholds and Classifications. ERMA NewZealand, Wellington.EU (2000). EU guidance (2000): Guidance document on Persistence in soil <strong>under</strong> Council Directive91/414/EEC (9188/VI/97 rev. 8)EU (2002). Guidance Document on terrestrial ecotoxicology <strong>under</strong> Council Directive 91/414/EEC,SANCO/ 10329/2002 rev. 2 final, 2002EU (2003). Monograph prepared in <strong>the</strong> context <strong>of</strong> <strong>the</strong> inclusion <strong>of</strong> <strong>the</strong> following activesubstance in Annex 1 <strong>of</strong> <strong>the</strong> Council Directive 91/414/EEC. Dichlorvos, Vol 1, Report &Proposed Decision.EU (2005). Draft Assessment Report – Dichlorvos (public version). Initial risk assessmentreport provided by <strong>the</strong> rapporteur Member State, Italy, <strong>for</strong> <strong>the</strong> existing active substancedichlorvos, <strong>of</strong> <strong>the</strong> second stage <strong>of</strong> <strong>the</strong> review programme referred to in Article 8(2) <strong>of</strong> CouncilDirective 91/414/EEC.EU (2007). COMMISSION DECISION <strong>of</strong> 6 June 2007 concerning <strong>the</strong> non-inclusion <strong>of</strong> dichlorvos inAnnex I to Council Directive 91/414/EEC and <strong>the</strong> withdrawal <strong>of</strong> authorisations <strong>for</strong> plant protectionproducts containing that substance (notified <strong>under</strong> document number C(2007) 2338) OJ L145/16.FAO/WHO (1970) Evaluations <strong>of</strong> some pesticide residues in food, dichlorvos.Horticulture NZ (2008) New Zealand Code <strong>of</strong> Practice <strong>for</strong> <strong>the</strong> Management <strong>of</strong> <strong>the</strong> Tomato/PotatoPsyllid in Greenhouse Tomato and Capsicum Crops. Edition 1.HSNO Chemical Classification In<strong>for</strong>mation Databasehttp://www.ermanz.govt.nz/hs/compliance/chemicals.htmlNew Zealand Standard 8409 (2004). Management <strong>of</strong> agrichemicals.NCGA (2009). The use <strong>of</strong> dichlorvos in <strong>the</strong> New Zealand Cymbidium industry. Report prepared by<strong>the</strong> Northland Cymbidium Growers Association <strong>for</strong> submission to <strong>the</strong> Environmental RiskManagement Authority.PMRA (2008). Dichlorvos Interim Measures. Re-evaluation note. Rev 2008-04Rautmann D., Streloke M., & Winkler R. (2001). New, basic drift values in <strong>the</strong> authorizationprocedure <strong>for</strong> plant protection products. In : Forster R, Streloke M, Workshop on risk assessment andrisk mitigation measures in <strong>the</strong> context <strong>of</strong> <strong>the</strong> authorization <strong>of</strong> plant ptrotection products (WORMM).Mitt. Biol Bundesanst Land –Forstwirtsch Berlin-Dahlem 383, 133-141Dichlorvos reassessment – application Page 435 <strong>of</strong> 436
Urban D.J., Cook, N.J. (1986). Hazard Evaluation Division Standard Evaluation Procedure:Ecological Risk Assessment. EPA 540/9-85-001. United States Environmental Protection AgencyOffice <strong>of</strong> Pesticide Programs, Washington DC, USA.USEPA AgDrifthttp://www.agdrift.com/AgDRIFt2/Download.htmUSEPA SCI-GROW model Screening Concentration In Ground Waterhttp://www.epa.gov/oppefed1/models/water/scigrow_description.htmUSEPA (2001) Generic Estimated Environmental Concentration Model v2 (GENEEC2). United StatesEnvironmental Protection Agency Office <strong>of</strong> Pesticide Programs, Washington DC, USAhttp://www.epa.gov/oppefed1/models/water/index.htm#geneec2USEPA (1997) Reregistration Eligibility Decision - Trichlorfon (RED) EPA-738-R-96-017USEPA (2006) Reregistration Eligibility Decision - Dichlorvos (DDVP) EPA 738-R-06-013USEPA (2006a) Reregistration Eligibility Decision <strong>for</strong> Trichlorfon (includes <strong>the</strong> 2001 Report onFQPA Tolerance <strong>Reassessment</strong> Progress and Interim Risk Management Decision (TRED) <strong>for</strong>Trichlorfon, EPA 738-R-01-009.Dichlorvos reassessment – application Page 436 <strong>of</strong> 436