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1 77X`TOXNET PIP - AZINOPHOS-METHYL Page 3 of 4 methyl is 136 mg/kg in young mallards, 74.9 mg/kg in young pheasant, 84.2 mg/kg in young chukar partridges, 262.0 mg/kg in chickens, and 32.2 mg/kg in bobwhite quail [13,17,27]. The dietary LC50 for azinphos-methyl is 639 ppm in Japanese quail, 1821 ppm in ring necked pheasant, and 1940 ppm in mallard duck [13,17]. . Effects on aquatic organisms: Azinphos-methyl is moderately to very highly toxic to freshwater fish. For most species,the LC50 values are less than 1 mg/L. The 96-hour LC50 for azinphos-methyl in rainbow trout is 0.003 mg/L [8,13]. Guthion-poisoned fish exhibit central nervous system impairment, including erratic swizi-iming accompanied by uncontrolled convulsions. Rapid gill movements, paralysis, and death follow in rapid succession [8]. Azinphos-methyl is highly toxic to aquatic invertebrates, shellfish, frogs, and toads [8]. The LC50 values are below 1 ug/L for many of the species [8,17]. . Effects on other organisms: Several studies have indicated that azinphos-methyl causes adverse effects in wildlife. Wild mammals and aquatic organisms appear to be more vulnerable than birds to hazards created by this material [29]. The EPA requires endangered species labeling for certain azinphos-methyl uses [17]. + Azinphos-methyl is toxic to honeybees and other beneficial insects [8,24]. It will cause severe bee losses if used when bees are present at treatment time or within a day thereafter [30]. A 90%mortality rate is seen in ! pollinating leaf cutting bees after a 9-day exposure to greenhouse alfalfa treated with azinphos-methyl [27]. Environfnental-'Fate: . Breakd6wn'in'soil and groundwater. Persistence of azinphos-methyl in soil is quite variable but is generally low under field conditions [19,31]. The half-life in sandy loam soil is 5 days. Its half-life in nonsterile soil is 21 days when oxygen is present or 68 days under oxygen-free conditions. In sterile soil, the half-life is reported to be 355 days. Azinphos-methyl is fairly immobile in soil because it adsorbs strongly to soil particles and has low water solubility. It has low leaching potential and is unlikely to contaminate groundwater [19,31]. It was not detected in 54 groundwater samples collected in New York state [32]. Azinphos-methyl is one of 118 synthetic organic chemicals that the state of Florida has designated for groundwater monitoring [33]. It was detected in only 5 out of 1628 wells sampled in 10 states from 1983 to 1991 [34]. The disappearance of azinphos-methyl from soil is more rapid in the surface layers (0 2.5 centimeters deep) than it is in the next deeper layer (2.4 to 7.5 cm). Biodegradation and evaporation are the primary routes of disappearance for azinphos-methyl. Azinphos-methyl is also subject to degradation by ultraviolet (UV) light from the sun and hydrolytic decomposition. Photodecomposrtion is particularly rapid at high levels of soil moisture and in the presence of UV light [31]. Rapid degradation of Gusathion was observed at temperatures higher than 37 C [29]. . Breakdown in water: In general, organophosphates, such as azinphos-methyl, are dissipated rapidly in water [35]. In pond water, it is subject to degradation by sunlight and microorganisms, with a half-life of up to 2 days. Volatilization from water is unlikely. Chemical hydrolysis is important in alkaline waters [12]. Azinphos-methyl is very stable in water below pH 10.0. Above pH 11.0, it is rapidly hydrolyzed to anthranilic acid, benzamide, and other metabolites. Azinphos-methyl has a low to medium tendency to adsorb to f sediments or suspended solids [12]. . Breakdown in vegetation: Residue levels of azinphos-methyl in crops are dependent on the rate and frequency of application, nature of the plant surface, and weather conditions such as rainfall, temperature, sunlight, humidity, and wind [24]. The half-life on vegetable and forage crops is 3 to 5 days under field conditions [24]. It gives effective protection for 2 or more weeks [36]. On treated apple trees, the half-life of ' this pesticide was about 2.6 to 6.3 days [28]. Hawthorn and American Linden trees have been injured by this material. It has also caused russeting on certain varieties of fruit [24]. Ph sical Pro ernes: . Appearance: Pure azinphos-methyl is a white crystalline solid. Technical azinphos-methyl is a brown waxy solid [13,37]. . Chemical Name: S-(3,4-dihydro-4-oxobenzo[d]-[1,2,3]-triazin-3-ylmethyl) 0,0-dimethyl phosphordithioate [13] . CAS Number: 86-50-0 . Molecular Weight: 317.33 . Water Solubility: 30 mg/L @ 25 C [13] . Solubility in Other Solvents: dichloromethane v.s.; toluene v.s. [13] . Melting Point: 65-68 C (technical) [13]; 73-74 C (pure form) [13] . Vapor Pressure: <1 mPa @ 20 C [13]