Toxicity of Alternatives to Chlorofluorocarbons: HFC-134a and HCFC-123

摘要

As part of the effort to phase out the use of stratospheric ozone-depletingsubstances, such as chlorofluorocarbons (CFC's) and Halon gases, the U.S. Navy is planning to substitute hydrofluorocarbon HFC-134a for the refrigerant CFC-12, and the Air Force is planning to substitute hydrochlorofluorocarbon (HCFC)-123 for the fire suppressant Halon 1211. The Navy asked the National Research Council (NRC) to review the toxicity data on HFC-134a and to recommend 1-hr and 24-hr emergency exposure guidance levels (EEGLs) and 90-day continuous exposure guidance levels (CEGLs). The Air Force requested the NRC to review the adequacy of the 1-min EEGL proposed by the Air Force for HCFC-123. In addition, the U.S. Environmental Protection Agency (EPA) requested the NRC to review the suitability of current methods for detecting and quantifying the risk of cardiac sensitization from exposure to CFCs and their substitutes. This report is intended to aid the Navy, the Air Force and EPA in using CFC substitutes safely.