Commentary and Scientific Review of Studies on Cardiac Function and Cardiac Sensitization Models

During the 1980's and into the 1990's, international agreements were developed that led to the phase out of the chlorofluorocarbons (CFC) because of the demonstrated effect these compounds have on depleting the protective ozone layer in the upper atmosphere. Because of the elimination of these compounds, the chemical industry began to introduce replacement compounds that have little or no effect on the ozone layer. These compounds, the hydrochlorofluorocarbons (HCFC) and hydrofluorocarbons (HFC), were introduced as replacements for the CFC in a variety of applications including refrigeration, aerosol propellants and fire extinguishing agents. In the last 15 years, several toxicological testing and research programs were initiated to examine the potential adverse health effects of these new alternatives. For the class of fluorocarbons, cardiac sensitization remains a potentially serious health outcome of overexposure to these compounds. Although routine toxicological testing of these compounds normally includes an evaluation of this endpoint, it would be advantageous to the military use of these compounds if methods were developed that would allow prediction of cardiac sensitization before the onset of a fatal arrhythmia. Prepared in cooperation with Environ, Inst. for Health Risk Science, Princeton, NJ and Geo-Centers Inc., Wright-Patterson Air Force Base, OH.