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

ERMA New Zealand was not able to quantitatively assess the riskof exposure to operators arising from the use of dichlorvosimpregnatedinsecticide strips (Use Scenario 31). Given the usepattern described for DDVP Insecticide strips, the criteria used todevelop the Use Scenario, ERMA New Zealand has undertakensemi-quantitative assessment. ERMA New Zealand estimates thatoperators will be exposed to 0.21 mg / hour of operations involvingDDVP strips associated with traps (which includes placing andreplacing strips in traps, and also routine inspection of traps).ERMA New Zealand estimates that operators will be exposed for aduration of 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. Comparingthe quantity of exposure to the AOEL (0.0014 mg/kg bw / day), fora 75 kg operator the daily AOEL equates to 0.105 mg dichlorvos.ERMA New Zealand considers that, whilst the estimations arelikely to be conservative in nature, the magnitude of adverse effectposed to operators is minor to major. ERMA New Zealandconsiders that the likelihood of minor to major adverse effectsoccurring is very unlikely. The level of risk to the health ofoperators is therefore negligible to low.4.4.4.2 Restricted entry exposure to operators:Only a few scenarios for existing uses of dichlorvos gaveacceptable risks for restricted entry workers. Acceptable restrictedentry generally requires the use of PPE and/or RPE plus in mostcases a time period called the Restricted Entry Interval (REI) 6 isalso needed. The level of risk of exposure associated with each UseScenario is detailed in Table 11, arising from restricted entry intotreated areas.ERMA New Zealand considers that the unrestricted entry timeperiods proposed for industrial buildings treated with dichlorvos,indicate that inhalation exposure to dichlorvos is acceptable withoutuse of RPE after such a time. ERMA New Zealand considers thatthe 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 useof PPE to prevent dermal exposure.ERMA New Zealand considers that the semi-quantitativeassessments carried out for operator exposure for Use Scenario 31is appropriate to use for the restricted entry operator exposure6A Restricted Entry Interval (REI) is a time period within which specific restrictions must be met. Examplesof the types of restrictions that may be imposed include use of PPE and RPE, entry is only allowed for certaintasks and for specified durations.Dichlorvos reassessment – application Page 50 of 436