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I:X'I'OXNfiT PIP - nME RYN http://ace.orst.edu/cgi-bin/ml'.s/01/pips/ametryn.htm cancer in humans (48,55). Organ Toxicity: Animal studies indicate that consuming large amounts of ametryn over a long period of time results in liver damage (48). Fate in Humans and Animals: Excretion of ametryn is rapid. In rats, all but 2 to 7% is eliminated in the urine and feces within 72 hours (58). ECOLOGICAL EFFECTS Effects on Birds: Ametryn is only slightly toxic to birds. The dietary LC50 (8 day) is 30,000 mg/kg for bobwhite quail and 23,000 mg/kg for mallard ducks (50). Effects on Aquatic Organisms: Ametryn is moderately toxic to fish. The LC50 for rainbow trout exposed for 96 hours is 8.8 mg/l. The LC50 for bluegill is 4.1 mg/1 and for goldfish it is 14.1 mg/I (49, 50). Ametryn is highly toxic to crustaceans and moderately to highly toxic to mollusks (8). Effects on Other Animals (Nontarget species): Ametryn is only slightly toxic to bees (49). ENVIRONMENTAL FATE Breakdown in Soil & Groundwater: Ametryn's half-life in soils, the amount of time it takes to degrade to half of the original concentration, is 70 to 250 days, depending on the soil type and weather conditions. Loss from the soil is principally by microbial degradation (48, 50). Ametryn moves both vertically and laterally in soil due to its high water solubility (57). Because it is persistent, it may leach as a result of high rainfall, floods, and furrow irrigation (48). In a study of surface and groundwater contaminants in the U.S, ametryn was found in six states, in very few surface water samples and in 4% of the groundwater samples. The maximum concentration found was 0.1 micrograms/1 in surface water and 450 micrograms/1 in groundwater(54). Breakdown in Vegetation: Ametryn is broken down into non-toxic substances by tolerant plants and, to a lesser extent, by sensitive plants (50). PHYSICAL PROPERTIES AND GUIDELINES: Physical Properties: • Appearance: White Powder • Chemical Name: 2-(ethylamino)-4-isopropylamino-6-methyl-thio-s-triazine • CAS Number: 834-12-8 • Molecular Weight: 227.3 • Water Solubility: 185 mg/1 at 20 degrees C. It dissolves readily in organic solvents including hexane, toluene, methanol, and acetone (50, 54). • Solubility in Other Solvents: Soluble in acetone (610), methanol (510), toluene (470), n-octanol (220), hexane (58) • Melting Point: 84-85 degrees C (50) • Vapor Pressure: 0.365 mPa • Partition Coefficient: 676 (50). • Adsorption Coefficient: Not Available Exposure Guidelines: • HA: 0.06 mg/1(lifetime); 8.6 mg/1(child) (57). • DWEL: 0.3 mg/1(57). 2 o1' 3 5/12/00 2:22 PM