Toxicological profiles of HFC-245fa (1,1,1,3,3-pentafluoropropane)

HFC-245fa, a colourless liquid or gas, is a non-ozone depleting alternative for trichlorofluoromethane (CFC-11) and dichlorofluoroethane (HCFC-141b). In the atmosphere, HFC-245fa degrades over a lifetime of 7.2 years, to give mainly carbon dioxide and hydrogen fluoride.

Its global warming potential is 950 compared to carbon dioxide for an integration time horizon of 100 years. This compares with a global warming potential for CFC-11 of 4,000 and for HCFC-141b of 600. In experimental animals HFC-245fa possesses a low order of acute inhalation toxicity, although it may sensitise the heart at high exposure levels (44,000 ppm or greater; >241,000 mg/m³). Long-term exposure to HFC 245fa vapour at high concentrations (50,000 ppm; 274,000 mg/m3) was tolerated with only minimal signs of toxicity. At that level HFC 245fa demonstrated no developmental effects. In genetic testing, HFC 245fa was not mutagenic in bacteria (Ames test), but induced some chromosome aberrations in cultured human lymphocytes. No micronuclei were found in mice exposed (in vivo) to 100,000 ppm (548,000 mg/m3) of HFC-245fa.

These data, complemented by data on analogous substances, suggest a low order of genotoxic and carcinogenic hazard on the part of HFC-245fa. With respect to environmental organisms, HFC 245fa showed no significant toxicity to water fleas or trout at 80 to 90 mg/l, the highest levels tested. As expected for this class of chemicals, biodegradation and bioaccumulation of HFC-245fa were minimal.

Joint Assessment of Commodity Chemicals No. 44
1,1,1,3,3-pentafluoropropane (HFC-245fa)
ECETOC, June 2004