Application for the Reassessment of a Hazardous Substance under ...

3.3 International regulatory position3.3.1 In recent years, dichlorvos has been subject to review in Australia (APVMA), theUSA (US EPA), Canada (PMRA) and Europe (EU). Details of these reviews arecontained in Appendix K and are summarised below.3.3.2 The APVMA (2008) is proposing to restrict the use of dichlorvos. Remaining usesare those in which exposure of operators and bystanders is minimised either byautomatic application to enclosed spaces or use of small volumes, for example fortreatment of wasp nests. In either case a minimum of elbow length butyl rubbergloves and chemical resistant clothing and in many applications a respirator isprescribed. Restricted entry intervals of 96 hours (4 days) for enclosed spaces or 4hours for glasshouses are prescribed. Indoor domestic use is not expected giventhese restrictions. Currently the only application involving field crops in Australia isfor avocados, but the APVMA proposed that broadacre application to this cropshould be discontinued. Veterinary treatment of horses using adichlorvos/oxibendazole paste is supported.3.3.3 In the 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 for bulk, packaged andbagged raw and processed agricultural commodities; food manufacturing/processingplants; animal premises; and non-food areas of food-handling establishments. It isalso registered for direct dermal pour-on treatment of cattle, and treatment of poultryhouses. It is not registered for direct use on any field grown commodities. Shortlyprior to completion of the USEPA (2006) review, the registrants withdrew use ofhand-held foggers in mushroom houses, greenhouses and warehouses, addedcoveralls to the required PPE for mushroom house hose-end sprayers and setrestricted entry intervals of 24 hours, reducible to 18 hours in mushroom houses and12 hours in greenhouses, if residual concentrations were demonstrated to have fallenbelow specified concentrations. Labelling of pest strips was also to be amended tothe effect that they should only be used in areas occupied for < 4 hours / day and foragricultural commodities. All other uses were retained (USEPA, 2006).3.3.4 In Canada, interim measures similar to the changes implemented in USEPA (2006)have been introduced (PMRA, 2008).3.3.5 Dichlorvos is not registered for 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 under review under the Biocides Directive.3.4 Mode of action3.4.1 Dichlorvos is an acetylcholinesterase inhibitor active through inhalation, contact andoral exposure.3.5 Review of hazardous properties3.5.1 The physico-chemical properties of dichlorvos and its formulations are described inAppendix A.3.5.2 The toxicology of dichlorvos is summarised in Appendix G.3.5.3 Dichlorvos is of high acute toxicity by oral, dermal and inhalation routes ofexposure. It is an eye and skin irritant and contact sensitiser. Of the 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 of its effects by single exposure for oral,Dichlorvos reassessment – application Page 23 of 436