INVIVO METABOLISM OF THE HYDROCHLOROFLUOROCARBON 1,1-DICHLORO-1-FLUOROETHANE (HCFC-141B)

Hydrochlorofluorocarbons (HCFCs) are being developed as substitutes for chlorofluorocarbons (CFCs) that deplete stratospheric ozone (1). 1,1-Dichloro-1-fluoroethane (HCFC-141b) is a potential substitute for CFC-11 in foam-blowing operations (2), and a mixture of HCFC-141b and HCFC-123 is an effective substitute for CFC- 113 which is used as a cleaning agent in the computer industry (3). U.S. production of CFC-11 and CFC-113 in 1986 amounted to 90,000 and 79,000 metric tons, respectively. [36Cl]HCFC-141b undergoes dechlorination when incubated with rat hepatic microsomal fractions in the presence of NADPH and oxygen (4), but no organic metabolites have been identified. Because of the potential commercial importance of HCFC-141b, the accompanying potential for human exposure, and the paucity of published information about its metabolism, we have studied its in vivo metabolic fate. Also, knowledge about the metabolism of HCFC-141b may have predictive value for the metabolism of other 1,1,1-trihaloethanes that are promising CFC substitutes. © 1991.