Subchronic toxicity of inhaled technical grade 1,3-dichloropropene in rats and mice

In order to provide a comprehensive subchronic inhalation toxicity study of the soil fumigant, technical grade 1,3-dichloropropene (DCPT), male and female Fischer 344 rats and B6C3F1 mice were exposed to 0, 10, 30, 90, or 150 ppm DCPT vapors 6 hr/day, 5 days/week for 13 weeks. The primary target tissues of inhaled DCPT were identified as the nasal mucosa of both sexes of rats and mice, and the urinary bladder of female mice. In addition, depressed growth rates of all animals exposed to 90 or 150 ppm DCPT (up to 20% in rats and 12% in mice) resulted in a variety of alterations in hematologic and clinical chemistry parameters, and changes in organ weights relative to controls. Nasal mucosal effects consisted of a dose-related slight degenerative effect of nasal olfactory epithelium or a mild hyperplasia of the respiratory epithelium or both in all animals exposed to 90 or 150 ppm and 2 of 10 male rats exposed to 30 ppm DCPT. Some focal areas of respiratory metaplasia were also noted in high exposure group mice. Urinary bladder effects consisted of a diffuse, moderate hyperplasia of the transitional epithelium in female mice exposed to 90 or 150 ppm DCPT. No treatment-related effects were observed in rats or mice exposed to 10 ppm DCPT vapors.