Groups of 10 female Cri:CD-1(ICR)BR mice were fed diets containing 0, 20, 100, 500, or 1000 ppm of the test substance. Groups of 10 male Crl:CD-1 (ICR)BR mice were fed diets containing 0, 20, 100, 500, or 2000 ppm of the test substance. After approximately 8 weeks of feeding, the 2000 ppm dose level was reduced to 1000 ppm, due to mortality, for the remainder of the study. Equivalent mean daily intakes were 0, 3.2, 15, 78, or 320/166 mg/kg for males and 0, 4.2, 20, 104, or 228 mg/kg for females. Body weights, food consumption, and clinical observations were evaluated weekly. Cage-side examinations for mortality were performed daily. After 13 weeks of dietary exposure, all surviving mice were necropsied. A gross and microscopic examination was performed. On all surviving animals and animals found dead or sacrificed in extremis.