Chronic Inhalation Toxicity/Carcinogenicity Study in Rats Exposed to Fluorocarbon 113 (FC-113)

Chronic Inhalation Toxicity/Carcinogenicity Study in Rats Exposedto Fluorocarbon 113 (FC-113). Trochimowicz, H. J., Rusch, G.M., Chiu, T., and Wood, C. K. (1988). Fundam Appl. Toxicol.11, 68–75. Groups of 100 male and 100 female CitCDBR ratswere exposed by whole-body inhalation to FC-113(1,1,2-trichloro-1,2,2-trifluoroethane)for 6 hr a day, 5 days a week for 24 months. Average exposureconcentrations (? 1 SD) were 0.0 (control), 2000 ? 100, 10,000? 500, and 20,000 ? 1000 ppm (v/v), respectively. Body weightswere consistently lower in both male and female rats in the20,000 ppm exposure group after approximately 1 and 4 months'exposure, respectively, and in female rats after 12 months'exposure at 10,000 ppm. Observations of appearance and behavior,mortality, and clinical laboratory measurements were unremarkableduring the 24-month exposure period. Despite exposure levelsas high as 20,000 ppm, only occasional slight increases in urinaryfluoride were seen. Microscopic examination of tissues fromrats examined during and at the end of the 24-month study revealedno evidence of compound-related toxicity or carcinogenicity.Based mainly on a 5 to 10% decrease in body weight gain at the10,000 and 20,000 ppm exposure levels, the no-observed-effectlevel for FC-113 in this study was 2000 ppm.