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

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 of effects;Results of other trials are equivocal. APVMA (2008) mention theresults of a foliar residue study in which the LD 50 was reported tobe 0.2 kg ai/ha, which is less than New Zealand application rates,but no other information was available. By contrast, US EPA(2006) report the results of a study on the toxicity of foliar residuesto honey bees and showed residues of 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 other non-target invertebrates indicaterisks at field application rates.4.3.9.8 Terrestrial – plants:No data were identified to evaluate the effects of dichlorvos on plantseither through foliar or soil exposure.4.3.9.9 Bioconcentration:On the basis of 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 the substance isnot applied in a wide-dispersive manner that could expose the aquatic or terrestrialenvironments, and that dichlorvos is rapidly dissipated. This risk has not beenconsidered further.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 the aquaticor terrestrial environments. This risk has not been considered further.Identification of beneficial effects (benefits)4.3.12 ERMA New Zealand did not identify any beneficial effects on the environment fromthe use of dichlorvos.4.4 Human health and safetyIdentification of adverse effects (risks and costs)4.4.1 Each of the lifecycle activities listed in Table 9 has the potential to expose people todichlorvos.Assessment of potentially significant adverse effects (risks and costs)4.4.2 Given the default controls, any incidents would be likely to be localised but could beof minimal to major magnitude. The likelihood of effects resulting fromincidents/spills during manufacture, repackaging, local transport, storage or disposalDichlorvos reassessment – application Page 44 of 436