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EXTOXNET PIP - LAMBL`,CYHALOTHRIN ... Page 3 of 4 excreted via the urine and feces (12). Hydrolytic cleavage of the ester bond occurs, forming more polar, water-soluble compounds which are less toxic and more easily eliminated (12, 110). ECOLOGICAL EFFECTS • Effects on Birds: Lambda cyhalothrin's toxicity to birds ranges from slightly toxic to practically non-toxic. In the mallard duck, the reported oral LD50 is greater than 3,950 mg/kg (12, 107), and the reported dietary LC50 is 3,948 ppm (107). In bobwhite quail the reported dietary LC50 is greater than 500 ppm (12, 107). There is evidence that it does not accumulate in the eggs or tissues of birds (12). • Effects on Aquatic Organisms: Lambda cyhalothrin is very highly toxic to many fish and aquatic invertebrate species. Reported LC50s in these species are as follows: bluegill sunfish, 0.21 ug/L (12, 107); rainbow trout, 0.24 ug/L (12, 107); Daphnia magna, 0.36 ug/L (107); mysid shrimp, 4.9 ng/L (107); sheepshead minnow, 0.807 ng/L (107). A median effect concentration, EC50 (i.e. the concentration at which the effect occurs in 50% of the test population), for the eastern oyster of 0.59 ng/L has been reported (107). Bioconcentration is possible in aquatic species, but bioaccumulation is not likely. Bioconcentration in channel catfish has been reported as minimal, with rapid depuration (elimination) (111). A bioconcentration factor of 858 has been reported in fish (4, species unspecified), but concentration was confined to non-edible tissues and rapid depuration was observed (107). • Effects on Other Animals (Nontarget species): Lambda cyhalothrin is highly toxic to bees, with a reported oral LD50 of 38 ng/bee and reported contact LD50 of 909 ng/bee (0.9 ug/bee) (107). ENVIRONMENTAL FATE Breakdown of Chemical in Soil and Groundwater: Lambda cyhalothrin is moderately persistent in the soil environment. Reported field half-lives range from four to 12 weeks (107, 111, 112). Its field half-life is probably close to 30 days in most soils (112). It shows a high affinity for soil; the reported Koc is 180,000 (112). Lambda cyhalothrin is not expected to be appreciably mobile in most soils. There is little potential for groundwater contamination. Soils with high sand content or with very low organic matter content may tend to retain the compound to a lesser degree. In field studies of Karate, leaching of lambda cyhalothrin and its degradates from the soil were minimal (12, 107). Breakdown products formed in the soil environment are similar to those formed in mammalian systems, via the hydrolysis of the central ester bond and oxidation (12). Breakdown rates of both the technical product and Karate were similar under aerobic and anaerobic conditions (107, 111). Breakdown of Chemical in Surface Water: Lambda cyhalothrin has extremely low water solubility and is tightly bound to soil, it is therefore not expected to be prevalent in surface waters. One possible source of infiltration into surface waters would be surface runoff. In this event, the compound would most probably remain bound to the solid particle and settle to the bottom. Breakdown of Chemical in Vegetation: No data were available regarding the breakdown of lambda cyhalothrin in vegetation. PHYSICAL PROPERTIES AND GUIDELINES Physical Properties: • Appearance: Lambda cyhalothrin is a colorless solid at room temperature, but may appear yellowish in solution. http://extoxnet.orst.edu/pips/lambdacy.htm 9/21/2004