Health concerns
When pans are overheated beyond approximately 350 °C (660 °F) the PTFE coating begins to dissociate, releasing byproducts (PFOA) which can cause polymer fume fever in humans and can be lethal to birds. Concerns have been raised over the possible negative effects of using PTFE-coated cooking pans.[5][14][15][16][17]
Processing of PTFE in the past used to include Perfluorooctanoic acid (PFOA) as an emulsifier; however, PFOA is a persistent organic pollutant and poses both environmental and health concerns, and is now being phased out of use in PTFE processing.[18]
PTFE flakes that come off PTFE cookware poses no danger when ingested. This is because PTFE flakes are inert so they will travel through the body without being absorbed.[19]