Polytetrafluoroethylene

Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene and is a PFAS that has numerous applications. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally discovered the compound in 1938.

Polytetrafluoroethylene is a fluorocarbon solid, as it is a high-molecular-weight polymer consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances wet PTFE, as fluorocarbons exhibit only small London dispersion forces due to the low electric polarizability of fluorine. PTFE has one of the lowest coefficients of friction of any solid.

Polytetrafluoroethylene is used as a non-stick coating for pans and other cookware. It is non-reactive, partly because of the strength of carbon–fluorine bonds, so it is often used in containers and pipework for reactive and corrosive chemicals. Where used as a lubricant, PTFE reduces friction, wear, and energy consumption of machinery. It is used as a graft material in surgery and as a coating on catheters.

PTFE is one of the best-known and widely applied PFAS commonly described as persistent organic pollutants or "forever chemicals". Only since the start of the 21st century has the environmental impact and toxicity to human and mammalian life been studied in depth. For decades, DuPont used perfluorooctanoic acid (PFOA, or C8) during production of PTFE, later discontinuing its use due to ecotoxicological and health issues that led to legal actions. Dupont's spin-off Chemours today manufactures PTFE using an alternative chemical it calls GenX, another PFAS.