NTP technical report on the toxicity studies of Acetone in F344/N Rats and B6C3F1 Mice (Drinking Water Studies) (CAS No. 67-64-1).

Toxicity studies were conducted by administering acetone (greater than 99%percnt; pure) in drinking water to groups of F344/N rats and B6C3F1 mice of each sex for 14 days or 13 weeks. Fourteen-Day Studies: All rats and mice receiving concentrations as high as 100,000 ppm acetone in drinking water lived to the end of the 14-day studies. The mean body weights of male rats receiving 50,000 or 100,000 ppm and female rats given 100,000 ppm were lower than those of controls. Body weights of all groups of mice were similar. Kidney and liver weight to body weight ratios for exposed rats and mice were greater than those for controls. Histopathologic changes were not seen in these organs in rats or in the kidney in mice. Centrilobular hepatocellular hypertrophy was noted in male and female mice receiving 20,000 and 50,000 ppm acetone, respectively. Thirteen-Week Studies: All rats lived to the end of the 13-week studies (drinking water concentrations as high as 50,000 ppm). The final mean body weights of rats receiving 50,000 ppm were 19%percnt; lower than that of controls for males and 7%percnt; lower for females. Water consumption by all rats that received 50,000 ppm acetone and females that received 20,000 ppm or more was notably lower than that by controls. Liver and kidney weight to body weight ratios were increased for male and female rats receiving 20,000 ppm or greater. Caudal and right epididymal weights and sperm motility were decreased for male rats given 50,000 ppm, and the percentage of abnormal sperm was increased. Leukocytosis and thrombocytopenia were observed at 20,000 ppm and above (males and females), and reticulocytopenia and erythrocytopenia were seen at 5,000 ppm and above (males). These changes, in addition to increase in erythrocyte size (MCV), are consistent with macrocytic anemia. Splenic pigmentation (hemosiderosis) noted in dosed male rats was apparently related to these changes. The increased incidence and severity of nephropathy observed in dosed male rats were considered the most prominent chemically related findings in this study. All mice lived to the end of the 13-week studies (drinking water concentrations up to 20,000 ppm for males and up to 50,000 ppm for females). The final mean body weights of dosed and control mice were similar. Water consumption by female mice that received 50,000 ppm acetone was notably lower than that by controls. The absolute liver weight and the liver weight to body weight ratio were significantly increased for females receiving 50,000 ppm, and the absolute spleen weight and the spleen weight to body weight ratio were significantly decreased. Results from the hematologic analyses did not show any biologically significant effects. Centrilobular hepatocellular hypertrophy of minimal severity was seen in 2110 female mice receiving 50,000 ppm. No compound-related lesions were found in male mice. In summary, the results from these studies show that acetone is mildly toxic to rats and mice when administered in drinking water for 13 weeks. Minimal toxic doses were estimated to be 20,000 ppm acetone for male rats and male mice and 50,000 ppm acetone for female mice. No toxic effects were identified for female rats. The testis, kidney, and hematopoietic system were identified as target organs in male rats, and the liver was the target organ for male and female mice. Synonyms: 2-propanone; dimethyl ketone; pyroacetic acid. (NOTE: These studies were supported in part by funds from the Comprehensive Environmental Response, Compensation, and Liability Act trust fund (Superfund) by an interagency agreement with the Agency for Toxic Substances and Disease Registry, U.S. Public Health Service.)