The Chronic Toxicity and Oncogenicity of Inhaled Technical-Grade 1,3-Dichloropropene in Rats and Mice

The Chronic Toxicity and Oncogenicity of Inhaled Technical-Grade1,3-Dichloropropene in Rats and Mice. LOMAX, L, G., STOTT, W.T., JOHNSON, K. A., CALHOUN, L. L., YANO, B. L., AND QUAST,J. F. (1989). Fundam. Appl. Toxicol. 12, 418–431. Maleand female Fischer 344 rats and B6C3F1 mice were exposed byinhalation to target concentrations of 0, 5, 20, or 60 ppm (0,22.7, 90.8, or 272 mg/m³) technical-grade 1,3-dichloropropene(DCPT) 6 hr/day, 5 days/week, for upto 2 years. Ancillary groupsof rats and mice were exposed for 6- and 12- month periods.Significant treatment-related nonneoplastic changes followingexposure for 2 years were morphological alterations in the nasaltissues of rats exposed to 60 ppm and mice exposed to 20 or60 ppm DCPT. In addition, mice exposed to 20 or 60 ppm had hyperplasiaof the transitional epithelium lining the urinary bladder. Survivalof male and female rats and mice exposed to DCPT was similarto that of the corresponding controls. No statistically increasedtumor incidence was observed in treated rats. The only neoplasticresponse observed in mice was an increased incidence of benignlung tumors (bronchioloalveolar adenomas) in male mice exposedto 60 ppm DCPT (22/50 versus 9/50 in controls).