Abstract
Quantitative evidence was obtained which indicates that the principal toxic component in the pyrolysate from PTFE (Teflon 5) at the 1st temperature at which rat mortality is observed (Approximate Lethal Temperature, ALT), is a particulate material which may have other toxicants adsorbed on it. The toxicity of this particulate varies, depending upon the conditions under which it is generated. At 30oC above the ALT, perfluoroisobutylene could be the principal toxic agent. The data correlate well with known chemical reactions as well as observations and hypotheses of other investigators.