1,2,3-TRICHLOROPROPANE - A MULTISITE CARCINOGEN IN RATS AND MICE

1,2,3-Trichloropropane was evaluated in 2-year toxicology and carcinog enesis studies by the National Toxicology Program. The selection of th is chemical for study was based on the potential for human exposure, i ts positive in vitro genotoxicity, and the carcinogenicity of structur ally related chemicals. During the 2-year study 1,2,3-trichloropropane was administered in corn oil by gavage 5 days per week; groups of 60 F344/N rats received 0, 3, 10, or 30 mg/kg, while groups of 60 B6C3F1 mice received 0, 6, 20, or 60 mg/kg. Because of reduced survival assoc iated with the development of chemical-related neoplasms, rats that re ceived 30 mg/kg were terminated at 65 weeks (females) or 76 weeks (mal es). Similarly, mice that received 60 mg/kg were terminated at 73 week s (females) or 79 weeks (males), while groups of mice that received 20 mg/kg were terminated at 88 weeks. 1,2,3-Trichloropropane induced ben ign and/or malignant neoplasms at multiple sites in both rats and mice ; this included increased incidences of benign and malignant neoplasms of the squamous epithelium of the oral mucosa and forestomach of male and female rats, benign neoplasms of the kidney and pancreas and beni gn or malignant neoplasms of the preputial gland in male rats, maligna nt neoplasms of the mammary gland, and benign or malignant neoplasms o f the clitoral gland in female rats. In mice, 1,2,3-trichloropropane i nduced a low incidence of malignant neoplasms of the oral mucosa in fe males, high incidences of benign and malignant neoplasms of the forest omach in males and females, benign neoplasms of the liver and harderia n gland of males and females, and uterine neoplasms in females. (C) 19 95 Society of Toxicology.