installed. Mineral oil used with R-12 is not compatible with R-134a. Some oils designed for conversion to R-134a are advertised as compatible with residual R-12 mineral oil. Another replacement for R-12 is the highly flammable, but truly drop-in HC-12a, whose flammability has led to injuries and deaths. Dangers Aside from its immense environmental impacts, R12, like most chlorofluoroalkanes, forms phosgene gas when exposed to a naked flame. Properties Table of thermal and physical properties of saturated liquid refrigerant 12: Gallery References External links NOAA/ESRL CFC-12 global measurements Overview of Freon-12 and some of its environmental problems MSDS at Oxford University Thermochemistry data at chemnet.ru IR absorption spectra CDC - NIOSH Pocket Guide to Chemical Hazards Halomethanes Chlorofluorocarbons Ozone depletion Greenhouse gases Refrigerants Belgian inventions