TEXT SEARCHABLE DOCUMENT DP Barcode: D345948 July 25,2008 MEMORANDUM SUBJECT: Section 3 Request for Additional Uses of Emamectin Benzoate (PC Code: 122806); Insecticide Product Proclaim@ (EPA Reg. No. 100-904) for Tree Nuts (Group 14) and Pistachios ?/L7/08 FROM: Lucy Shanaman, Chemist 4~ Stephen Carey, Biologist F/z~/"' Environmental Risk Branch 111 Environmental Fate and Effects Division (7507P) TO: John Herbert, RM 07 Amer Al-Muddallal Insecticide-Rodenticide Branch Registration Division (7505P) 7 /z~/DP THRU: Thomas Bailey, Acting Branch C Mark Corbin, Acting RAPL 7:~s- 0% Environmental Risk Branch I11 Environmental Fate and Effects ~ivision(7507P) Attached please find the Environmental Fate and Effects Division's (EFED) environmental risk assessment for the proposed new uses of emamectin benzoate as an insecticide on tree nuts, pistachios and almond hulls. This risk assessment covers one formulated product, Proclaim@ Insecticide, a water-soluble granular product. The proposed maximum labeled application rate for tree nuts and pistachios depend on the degree of infestation of the target pests. The label recommends an application rate of 3.2 oz (0.01 lbs a.i./A) for low to moderate infestations and 4.8 oz (0.015 lbs a.i.lA) for severe infestations. Multiple applications are allowed with a 7-day interval up to the maximum seasonal load of 14.4 oz (0.045 lbs a.i./A). Emamectin benzoate can be applied via ground, air blast, or air. The application rates for the proposed new uses are the same of the registered uses on pome fruits. The application methods for the proposed new uses are ground and air blast applications while aerial applications are not permitted. Consequently, this risk assessment mainly focuses on the maximum application rate of 0.015 lb a.i./A applied three times via air blast with 7-day reapplication intervals to assess if emamectin benzoate poses additional risks to other taxonomic groups not identified in previous risk assessments. The risk conclusions based on the minimum application rate of 0.01 lb ailA applied 4 times with 7-day reapplication intervals via ground or air, three ground applications at 0.015 lb ai/A with 7-day reapplication intervals, the problem formulation, conceptual model and analysis plan can be found in the previous assessment on pome fruits (D309154). Key findings of this risk assessment are as follows: To comply with Agency's current standards, there is an additional risk identified in this risk assessment for the proposed uses on tree nuts and pistachios. Potential risk to terrestrial plants is identified this time because toxicity data are not available; the potential risks to terrestrial monocots and dicots cannot be precluded at this time and assumed directly affected until data indicate otherwise. For other taxonomic groups assessed, the risk conclusions in this assessment for emamectin benzoate applications on tree nuts and pistachios are mostly identical as of the registered use on pome hits (see D309154). The most notable change in this assessment is that the chronic risk level of concern was not exceeded for fieshwater invertebrates. Since the chronic LOC was not exceeded from air blast applications, EFED expects no LOC exceedance of chronic risk to freshwater invertebrates from ground applications because EECs resulting from ground applications are lower than air blast applications. Therefore, emamectin benzoate treatments on tree nuts and pistachios are not anticipated to effect reproduction, growth, or survival of young of freshwater invertebrates when exposed to the insecticide via ground or air blast applications. Similar to pome fruits, the proposed emamectin benzoate uses on tree nuts and pistachios pose risk at the Agency's LOCs to birds, reptiles, terrestrial-phase amphibians, mammals, and aquatic invertebrates and concerns for terrestrial plants. EFED also presumes that insects and arachnids located in the area of emamectin benzoate applications are at risk since emamectin benzoate is an insecticide. New uncertainties were not identified in this assessment; however, uncertainties fkom previous assessments have not been addressed. Principle among these is that risk to birds and mammals may have been underestimated because ernamectin benzoate has been shown to induce neurotoxic effects that could result in decreased survival at sublethal doses. The acute risk assessment, however, was based on lethality, which occurred at higher exposure levels, because the neurotoxic effects could not be quantitatively related to survival or reproductive success. There were no acute or chronic LOC exceedances for fish, aquatic-phase amphibians and aquatic plants, and the chronic LOC was not exceeded for freshwater invertebrates. Uncertainties and data gaps are summarized in Table D of this assessment. Data gaps include studies in sediment dwelling organisms, lack of an acceptable life-cycle study in mysid shrimp, more sensitive analytical detection methodology, terrestrial plant toxicity data, and degradate toxicity data. See Table D in this assessment for additional details. Environmental Fate and Ecological Risk Assessment for the Registration of Emameetin Benzoate Use on Tree Nuts and Pistachios (New Use) PC Code 122806 OCH, R=C2H5 for E1a R=CH3 for Bib "o -Jk,ys2--,ru I. EXECUTIVE SUMMARY A. Nature of Chemical Stressor Emamectin benzoate (Proclaim@)is an avermectin class insecticide developed for the control of lepidopteran insects. This class of pesticide consists of homologus semi-synthetic macrolides that are derived from the natural fermentation products of Streptomyces bacteria. It kills insects by disrupting neurotransmitters, causing irreversible paralysis. It is more effective when ingested, but it also somewhat effective on contact. Target pests are numerous and include various moths, leafiollers, hitworms, and caterpillars. Emamectin benzoate is currently registered for use on fruiting vegetables, brassica head and stem vegetables, leafy vegetables and pome fruit. Current end use products include an emulsifiable concentrate (Proclaim 0.16 EC). It is applied via ground, air, or as a spray blast. The Agency has identified four degradates of concern based on structural similarity to emamectin benzoate (see p. 5-6 for additional discussion on the degradates): (8,9-20-4"-epirnethylamino-4"-deoxyaverrnectin B 1 (8,9 ZMA isomer); 4"-epiamino-4"-deoxyavermectin B 1 (AB); avermectin B 1 monosaccharide (MAB); and 4"-epi-(N-formy1)-4"-deoxyavermectin B 1 (FAB) All of these degradation products form via photolysis of emamectin benzoate. This assessment considers exposure to emamectin benzoate and all degradates of concern. B. Previous Ecological Risk Assessments Conducted by EFED EFED conducted a new chemical review in 2000 (D226628), two new use reviews in 2002', several Section 18 reviews2, and a new use assessment for pome fruits in 2005~.New chemical assessed use patterns (application rate, interval, method) are lower than those proposed for the new uses on tree nuts and pistachios. Current risk conclusions are mostly identical to those presented in the previous assessment for emamectin benzoate use on pome hit. The principle risks identified previously include risk to estuarinelmarine and freshwater invertebrates and herbivorous/insectivorous mammals and birds, including terrestrial-phase amphibians and reptiles at levels of concern (LOC) to the Agency. Potential risk to insects is identified as a concern to the Agency in these assessments. Terrestrial plants toxicity data were considered a data gap in previous assessment; however, to comply with Agency's current standards, the risks to terrestrial plants cannot be precluded at this time and assumed directly affected until data indicate otherwise. DP Barcodes 279840 and 279841 (cole crops, leafy vegetables, cotton, and tobacco). DP Barcodes include D223875, D223876, D239671, D239672, D255357, D279840, and D279841. DP Barcode 309 154 (pome fruit). C. Conclusions - Environmental Fate Characterization After emamectin benzoate enters the terrestrial environment, it is generally expected to dissipate relatively quickly (days to weeks), primarily from photolysis. However, if it gets incorporated into the soil or is attenuated from light as is expected for proposed use on tree nuts, then it may persist because it is resistant to other forms of degradation such as microbial metabolism and hydrolysis. Emamectin benzoate's low Henry's law constant and vapor pressure indicate that little of the chemical is expected to enter the air fiom soil or water. Due to its high adsorption to soil, emamectin benzoate is expected to typically enter surface water via soil erosion and will likely partition to the sediment when it enters water bodies. Due to its slow microbial degradation, emamectin benzoate may persist in the sediment after application if it is attenuated from light. Emamectin benzoate also possesses the potential to slowly leach to ground water, where it is expected to be stable. D. Conclusions - Environmental Exposure Characterization Based on emamectin benzoate's fate profile described above, exposure to terrestrial animals will likely occur principally fiom consumption of contaminated foliage. Emamectin benzoate penetrates the leaf tissue and forms a reservoir within treated leaves, which provides residual activity against foliage-feeding pests that ingest the substance when feeding. This may also result in increased opportunity for exposure to non-target animals that consume treated leaves. Emamectin benzoate concentrations