Un«.dSutM Offic* o( Pestodes &Mraw«ntal Pnxactwn and Tome Substances A°*nCV . (H75°iq 540/FS-90-095 EPA Pesticide Fact Sheet Name of Chemical: Reason for Issuance: Date Issued: Fact Sheet Number: Avermectin Changed Use Pattern JUL 20 iggo 89.2 - indoor Use 1. Description of Chemical Generic Name: Avermectin [A mixture of avermectins containing 80% avermectin B^a (5-0-demethyl avermectin A^a) and <_ 20% avermectin Bjh (5-0-demethyl-25-de(l-methylpropylT-25- (l-methylethyl) avermectin Ala)] Conmon Name: Abamectin Trade Names: Affirm , Agrimec , Avid , MK-936, Zephyr , Avert EPA Shaughnessy Code: 0122804 Chemical Abstracts Service (CAS) Numbers: 65195-55-3 and 65195-56-4 Year of Initial Registration: 1986 Pesticide Type: Insecticide/Miticide Chemical Family: Avermectins (macrocylic lactones isolated from soil organism fst- rppt-nmyrps auprmi h i 1 U.S. Producers: Merck S. Co., Inc. 2. Use Pattern/Formulations/and Product Limitations* Application Sites: Garages, Homes, Non-Patient Areas of Hospitals and Nursing Homes and the Nonfood/feed Areas of Hotels, Motels, Nursing Homes, Transportation Equipment (Buses, Boats, Ships, Trains, Planes), Utilities, Warehouses, and Other Conmercial and Industrial Buildings. Type of Formulation: Whitmire Avert PT 310 Abamectin dust containing 0.05% of the active ingredient abamectin. Method of Application: Localized spot treatment, crack and crevice treatment with hand or power duster. * This fact, sheet, refers to indoor uses only. See EPA Fact. Sheet. 89.1 for description of other uses of products containing Abamectin. ------- 2 Rate of Application: Dust lightly and uniformly to infested sites. 12-24 spot treatments (2 ft x 2 ft area) per 100 sq ft. Limitations: For Use By Oosnercial Applicators. Not for use in the food/feed areas of coranercial food/feed handling establishment, restaurants or other areas where food is commercially prepared or processed. 3. Science Findings Summary Science Statement Technical avermectin exhibits high mammalian acute toxicity. The results of the acute toxicity tests on the indoor use formulation indicates that the product is of low toxicity. It is not considered to be mutagenic and does not sensitize skin. It is not readily absorbed by mammals and the majority of the residue is excreted in the feces within 2 days. The 24- month rat chronic feeding/oncogenicity study and 94-week mouse chronic toxicity oncogenicity study were negative for oncogenic potential. The results of a series of developmental toxicity studies (rat, rabbit, mouse) have been evaluated and showed that avermec-tin B, produces developmental toxicity (cleft palate) in the CFj mouse. Toxicology data were also evaluated for the delta-8,9-isomer of avermectin B, which is a plant photodegradate. This isomer possess avermectin like toxicological activity, it was concluded that the delta-8,9-isomer also produces developmental toxicity (cleft palate) in mice, but not in rats. Sufficient data are available to characterize avermectin from an environmental fate and ecological standpoint. Avermectin is extremely toxic to manmals and aquatic invertebrates and highly toxic to fish and bees. Avermectin is relatively non-toxic to birds. Avermectin undergoes rapid photolysis, is readily degraded by soil microorganisms and, due to its binding properties and low water solubility, is expected to exhibit little or no potential for leaching. Chemical/Physical Characteristics (Technical Grade) Physical State: Crystalline powder Color: Yellowish-white Odor: Odorless Melting Point; 155 - 157° C Vapor Pressure: 1.5 x 10~® torr Density: 1.16 + 0.05 at 21°C Solubility: Insoluble in water (<_ 5 ug/mL), readily soluble in organic solvents pH: NA. The avermectin molecule has neither acidic nor basic functional groups Octanol/Water partition Coefficient: 9.9 x 10-* ------- 3 Toxicological Characteristics Technical Grade Avermectin B-] o Dermal Sensitization: Negative for skin sensitization o Acute Oral LDjq - Rat; 10.6 mgAg (males), 11.3 mgAg (females) o 14-Week Oral Study - Rat: NOEL 0,4 mgAg/day (HDT) o 18-Week Oral Study - Dog: NOEL - 0.25 mgAg/day o Teratology Study - Rat: Negative for terata up to 1.0 mgAg/day. o Teratology Study - Rabbit: Teratogenic NOEL = 1.0 mgAg/day. o Teratology Studies - Mouse: Teratogenic LEL - 0.4 mgAg/day (cleft palate),* Teratogenic NOEL - 0.2 mgAg/day. o Maternotoxicity Studies - Mouse: LEL «= 0.075 mgAg/day (lethality); NOEL = 0.05 mgAg/day o 2-Generation Reproduction Study - Rat: NOEL * 0.12 mgAg/day; LEL = 0.40 mgAg/day (increased retinal folds in weanlings, increased dead pups at birth, decreased viability indices, decreased lactation indices, decreased pup body weights) o 1-Year Oral Study - Dog: NOEL = 0.25 mgAg/day; LEL = 0.50 mgAg/day (mydriasis in males and females) o 94-Week Chronic Toxicity/Oncogenicity Study - Mice: Oncogenic potential: Negative up to 8 mgAg/day (HDT); Systemic NOEL = 4 mgAg/day; Systemic LEL - 8 mgAg/day (Dermatitis in males, extramedullar hematopoiesis in the spleen in males, increased mortality in males, treaors and body weight loss in females) o 2-Year Chronic Toxicity/Oncogenicity Study - Rats: Oncogenic potential: Negative up to 2.0 mgAg/day (HDT); Systemic NOEL = 1.5 mgAg/day; Systemic LEL = 2.0 mgAg/day tremors in both sexes) o Metabolism Study - Rat: Hie metabolic T 1/2 in rats is 1.2 days o Ames Mutagenicity Assay: Negative o Mutagenicity Assay for Chromosomal Aberrations in vitro in Chinese Hamster Ovary Cells ------- 4 o Rat Hepatocyte Mutagenicity Study: Under conditions of the study, abamectin (0.3 and 0.6 raM) caused an induction of single strand DNA breaks in rat hepatocytes _in vitro; no effect was observed when the assay was carried out on hepatocytes from rats dosed in vivo at the LDm dose level (10.6 mgAg> • o In Vivo Bone Marrow Mutagenicity Cytogenic Study; Negative in male mice at doses of 1.2 and 12.0 mgAg Toxicity studies on the Delta-8#9-lsomer of Averinectin o Acute Oral LD^g - Mouse: > 80 mgAg (HOT) (males and females) o Teratology Study - Rat: Negative for terata up to 1.0 mgAg/day (HDT) o Teratology studies - Mouse: Teratogenic LEL = 0.10 mgAg/day (cleft palate); Teratogenic NOEL = 0.06 mgAg/day o Maternotoxicity Studies - Mouse: LEL = 0.50 mgAg/day (lethality); NOEL - 0.10 mgAg/day o 1-Generation Reproduction Study - Rat: NOEL = 0.4 mg/kg/day (HDT) o Ames Mutagenicity Assay: Negative Toxicity Studies for Whitmire Formulation Acute Oral Toxicity in Rats: LD50 « > 5.0 gAg Acute Dermal Toxicity in Rabbits: ld50 = > 2.0 gAg Acute Inhalation: LC50 - > Primary Eye Irritation in Rabbits: Primary Dermal Irritation in Rabbits: Dermal Sensitization: Ecological Characteristics Avian Oral (Bobwhite quail): lDcq > 2000 mgAg; LC50 - 3102 ppm Avian Dietary (Mallard duck): LC^g ¦ 383 ppm Freshwater Fish (Bluegill): LC50 - 9.6 ppb Rainbow trout: DCcq - 3.2 ppb Estuarine Fish (Fathead minnow): LCcq = 15 ppb Oyster Embryo Larvae: LC5Q « 430 ppb. Acute Freshwater Invertebrate (Daphnia): LC50 = 0.22 ppb Acute Estuarine Invertebrate (Shrimp, mysid): LC50 = 0.02 ppb Toxicity Category IV Toxicity Category III Waiver Granted Toxicity Category III Toxicity category IV Not a sensitizer ------- 5 Environmental Characteristics Avermectin is stable to hydrolysis at ph 5, 7, and 9 and thus is not expected to hydrolyze in the environment. It photodegrades rapidly in water and soil with half-lives of less than 12 hours and 1 day respectively. Soil metabolism studies conducted in darkness indicate degradation does occur with a half-life of 2 weeks to 2 months under aerobic conditions. Anaerobic degradation is slower. It is not expected to accumulate in fish. Avermectin's solubility in water is determined ?to be 7.8 ppb. The field dissipation study indicates that avermectin, when applied directly to the soil, dissipates with a half-life of about a week but may persist longer if the pesticide is shaded. Due to its binding properties and low water solubility, Avermectin is expected to exhibit little or no potential for leaching. Tolerance Assessment This changed use pattern does not involve a food use and as such a tolerance assessment is not needed. Exposure Assessment Because of adverse developmental effects seen in animal studies, a margin of safety (MOS) for these effects (maternal toxicity and developmental toxicity) were calculated with respect to dermal exposure to applicators applying the dust product. Based upon surrogate exposure data and dermal absorption data in the monkey, the calculated MOS for applicators was found to exceed 100 in all instances. This MOS is sufficient to adequately protect these workers. 4. Sumwary of Regulatory Position and Rationale The Agency has determined that it should allow the unconditional registration of abamectin for indoor use in and around homes and the nonfood/nonfeed areas of commercial establishments for control of household pests, such as ants, cockroaches, etc. Adequate data are available to assess the acute and chronic toxicological effects of abamectin to humans. Since no crop, food or feed uses are proposed a tolerance assessment is not necessary. Although technical abamectin is highly toxic to aquatic organisms (invertebrates and fish) these use patterns (indoor uses) should not pose any environmental hazard. None of the criteria for unreasonable adverse effects listed in Section 154.7(a) of Title 40 of the U.S. Code of Regulations have been met or exceeded for this use. 5. Sunroary of Data Gaps There are no data gaps for this changed use pattern (non-food indoor use). ------- 6 6. Contact Person at EPA George T. LaRocca Product Manager 15 Insecticide-Rodenticide Branch Registration Division (H7505C) Office of Pesticide Program U.S. Environmental Protection Agency 401 M Street S.W. Washington, D.C. 20460 Office location and telephone number: Rra. 204, CM #2 1921 Jefferson Davis Highway Arlington, VA 22202 (703) 557-2400 Information Fact used to fulfill DISCLAIMER: Hie information presented in this Chemical Sheet is for informational purposes only and may not be data requirements for pesticide registration. ------- |