| Abstract |
A bioassay of technical-grade 1,1,2-trichloroethane for possible carcinogenicity was conducted using Osborne-Mendel rats and B6C3F1 mice. 1,1,2-Trichloroethane in corn oil was administered by gavage, at either of two dosages, to groups of 50 male and 50 female animals of each species for 78 weeks. The high and low time-weighted average dosages of 1,1,2-trichloroethane were, respectively, 92 and 46 mg/kg/day for male and female rats, and 390 and 195 mg/kg/day for the male and female mice. For each species, 20 animals of each sex were placed on test as vehicle controls and 50 animals of each sex were placed on test as untreated controls. No neoplasms were observed at statistically significant incidences in male or female rats. In both male and female mice, administration of 1,1,2-trichloroethane was associated with a significantly increased incidence of hepatocellular carcinomas. There was a positive dose-related association between administration of 1,1,2-trichloroethane and the incidence of pheochromocytoma of the adrenal gland. The results of this study do not provide convincing evidence for the carcinogenicity of 1,1,2-trichloroethane in Osborne-Mendel rats. Under the conditions of this bioassay, 1,1,2-trichloroethane is carcinogenic in B6C3F1 mice, causing hepatocellular carcinomas and adrenal pheochromocytomas. |
