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i greater than 500 mg/kg. The dermal LD50 for technical trifluralin in rabbits is greater than 2000 mg/kg. The 1-hour inhalation LC50 for technical trifluralin in rats is greater than 2.8 mg/L [58]. Nausea and severe gastrointestinal discomfort may occur after eating trifluralin. Trifluralin does not cause skin irritation. When applied to the eyes of rabbits, trifluralin produced slight irritation, which cleared within 7 days [8]. Skin sensitization (allergies) may occur in some individuals [8]. Inhalation may cause irritation of the lining of the mouth, throat, or lungs [8]. • Chronic toxicity: Prolonged or repeated skin contact with trifluralin may cause allergic dermatitis [8]. The administration of 25 mg/kg/day to dogs for 2 years resulted in no observed toxicity [58]. In another study of beagle dogs, toxic effects were observed at 18.75 mg/kg/day. These included decreased red blood cell counts and increases in methemoglobin, total serum lipids, triglycerides, and cholesterol [13]. Trifluralin has been shown to cause liver and kidney E damage in other studies of chronic oral exposure in animals [139]. • Reproductive effects: The reproductive capacity of rats fed dietary concentrations of trifluralin as high as 10 mg/kg/day was unimpaired through four successive generations. Trifluralin administered to pregnant rabbits at doses as high as 100 mg/kg/day, and to rats at doses as high as 225 mg/kg/day, produced no adverse effect on either the mothers or offspring [58]. Loss of appetite and weight loss followed by miscarriages were observed when pregnant rabbits were fed high doses of.224 or 500 mg/kg/day. Fetal weight decreased and there was an increase in the number of fetal runts at the 500 mg/kg/day dosage [8]. It is unlikely effects on reproduction will be produced in humans at expected exposure levels. • Teratogenic effects: No abnormalities were observed the offspring of rats fed doses as high as 10 mg/kg/day for four generations [58]. Studies in the rat and rabbit show no evidence that I` trifluralin is teratogenic. The highest doses tested in these studies were 1000 mg/kg/day in rats and 500 mg/kg/day in rabbits [138]. Trifluralin does not appear to be teratogenic. • Mutagenic effects: No evidence of mutagenicity was observed when trifluralin was tested in live animals, and in assays using bacterial and mammalian cell cultures [138]. • Carcinogenic effects: In a 2-year study of rats fed 325 mg/kg/day, the highest dose tested, malignant tumors developed in the kidneys, bladder, and thyroid [138]. However,more data are needed to characterize its carcinogenicity. • Organ toxicity: Liver, kidney, and thyroid damage appear to be the main toxic effects in chronic animal studies [139]. • Fate in humans and animals: Trifluralin is not readily absorbed into the bloodstream from the gastrointestinal tract; 80% of single oral doses administered to rats and dogs was excreted in the feces [8]. Ecological Effects: • Effects on birds: Trifluralin is practically nontoxic to birds [63]. The LD50 in bobwhite quail is greater than 2000 mg/kg, as it is in female mallards and pheasants [63]. These values are for the technical product. • Effects on aquatic organisms: Trifluralin is very highly toxic to fish and other aquatic organisms. The 96-hour LC50 is 0.02 to 0.06 mg/L in rainbow trout, and 0.05 to 0.07 mg/L in f bluegill sunfish [37]. The 96-hour LC50 in channel catfish is approximately 1.4 to 3.4 mg/L [37]. Variables such as temperature, pH, life stage, or size may affect the toxicity of the compound. Trifluralin is highly toxic to Daphnia, a species of small freshwater crustacean, with a 48-hour LC50 of 0.5 to 0.6 mg/L [140]. The compound shows a moderate tendency to accumulate in aquatic organisms. • Effects on other organisms: At exposure levels well above permissible application rates (100 mg/kg), trifluralin has been shown to be toxic to earthworms. However, permitted application