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,XT PIP - DIFLUBENZURON Page 2 of 3 _n three-generation study on rats at low doses showed no effect on mating performance. It does not appear that diflubenzuron has a significant effect on reproduction [16,28]. . Teratogenic effects: Diflubenzuron does not appear to be teratogenic. Newborn rats and rabbits did not develop any birth defects after their mothers were exposed to low levels of diflubenzuron (1 to 4 mg/kg/day) on days 6 to 18 of gestation [16,28]. . Mutagenic effects: Extensive testing on mamalian cells and on bacterial cells shows that diflubenzuron is not mutagenic [16,28]. e Carcinogenic effects: Rats fed diets containing low to moderate amounts of diflubenzuron daily for 2 years had no increase in the number of new or abnormal tissue growths or lesions. Mice fed low doses for 80 weeks showed no significant tumor development. Other studies on both species at higher levels were also negative for malignant tumors [16]. Diflubenzuron does not appear to be carcinogenic. . Organ toxicity: Animal studies have shown the liver and spleen to be target organs. . Fate in humans and animals: Intestinal absorption in mammals decreases with increasing dose levels [28]. For example, in rats , the total excretion in urine and bile decreased from about 50% of the dose at 4 mg/kg to only 4%at 900 mg/kg. Mice showed similar results. A cow given 10 mg/kg orally, eliminated almost all of the product over a 4-day period. There were only minute amounts of the pesticide in the milk. The chemical is not degraded in the digestive tract, but that which is absorbed by the gut is completely broken down before excretion [16]. Rabbits' skin absorbed only very small amounts, all of which was recovered in the urine. Chickens excreted almost all of an oral dose in 13 days. Their eggs had low levels of pesticide residues (0.3 to 0.6 mg/kg) from day 9 to the end of the 9-week study. Body tissues (non-fatty) do not retain diflubenzuron [16]. Ecological Effects: . Effects on birds: Diflubenzuron is practically nontoxic to wild birds. Bobwhite quail and mallard ducks both have an 8-day dietary LC50 of greater than 4640 ppm [4,7,8]. . Effects on aquatic organisms: Diflubenzuron is practically nontoxic to fish and aquatic invertebrates. The LC50 values (96-hour) for diflubenzuron in various fish are: bluegill sunfish, 660 mg/L; rainbow trout, 2.40 mg/L'; saltwater minnow, 255 mg/L; and channel catfish, 180 mg/L. In oyster larvae and juveniles EC50 values were 130 and 250 mg/L, respectively [4,7,8]. Arthropods are most susceptible in the premolting stage. For instance, fiddler crabs, exposed for as little as I week at levels up to 0.05'mg/L exhibited limb regeneration effects [29]. Fish tissue can show some traces of the metabolites when water is contaminated with diflubenzuron; however, tissue concentrations decline steadily with time in clean water. . Effects on other organisms: The compound is nontoxic to bees [4]. Environimental Fate:: . Breakdown in soil and groundwateri Diflubenzuron has a low persistence in soil. The rate of degradation in soil is strongly dependent on the particle size of the diflubenzuron [12]. It is rapidly degraded by microbial processes. The half-life in soil is 3 to 4 days [19]. Under field conditions, diflubenzuron has very low mobility [8,19]. . Breakdown in water:.dn sterilized water(no microbes), there appears to be little degradation under neutral or acidic conditions. However, under field conditions, it is degraded rapidly. Residues could not be detected in field water 72 hours after an application of 110 g/hectare. Other studies suggest a half-life of 1 to 3 weeks [4,7,8]• . Breakdown in vegetation: Very little diflubenzuron is absorbed, metabolized, or translocated in plants. Residues on crops such as apples have a half-life of 5 to 10 weeks. The half-life in oak leaf litter is 6 to 9 months [4,7.,8]. Physical Properties: . Appearance: Diflubenzuron is a white crystalline solid [7]. . Chemical Name: 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea [7] . CAS Number: 35367-38-5 . Molecular Weight: 310.70 . Water Solubility: 0.14 mg/L @ 20 C, insoluble [7] . Solubility in Other Solvents: DMSO s.; acetone s.s.; methanol s.