Abstract
The present paper summarizes data on the toxicity of hydrofluorocarbons（HFCs），
including 1,1,1,2,2-pentafluoroethane（HFC-125），1,1,1,2-tetrafluoroethane（HFC-134a），
1,1,1-trifluoroethane（HFC-143a），1,1-difluoroethane（HFC-152a），difluoromethane
（HFC-32），and 1,1,1,3,3-pentafluoropropane（HFC-245fa），used as refrigerants, published
in openly available scientific literature. Acute exposure to HFC-152a, but not other
HFCs, caused deaths in rats at 383,000 ppm. These HFCs, except for HFC-32, caused a
cardiac sensitization in dogs at high concentrations. Although myocarditis was found after
repeated exposure to HFC-245fa for 13 weeks at 10,000 ppm and above, no overt toxicity
was noted after repeated exposure to other HFCs. HFC-134a, HFC-32, and HFC-245fa
caused developmental toxicity at 50, 000 ppm, but these HFCs were not teratogenic. Toxic
effects of HFC-134a are relatively well reported, but limited information is available regarding
the toxicity of other HFCs. Animal studies are necessary for risk assessments of chemicals
because it is difficult to find alternative methods to determine the toxic effects of
chemicals. It is important to reduce emissions of organic vapors containing HFCs to
reduce the risk of exposure and protect public health.
