PFAS - Did You Know
Oct. 9 2018
Per- and polyfluorinated alkyl substances (PFAS) are referred to as “emerging contaminants”. A more appropriate term would be emerging contaminants of environmental concern as PFAS have a history that dates back to the late 1930’s.
Teflon® (polytetrafluoroethylene, PTFE) was accidently discovered in the laboratories of Dupont by Dr. Roy Plunkett in 1938. Trying to develop non-toxic refrigerants in the 1930s, Dr. Plunkett was using tetrafluoroethene gas. Upon opening one of the tetrafluoroethene gas cylinders, Plunkett found that the gas had disappeared, and in its place was a white, waxy solid. This solid was Teflon®.
At the time, there was no apparent commercial use for this material, until scientists developing the atomic bomb through the Manhattan Project presented Dupont with a problem. The development of the atomic bomb included the enrichment of uranium-235 (U235) using gaseous uranium hexafluoride (UF6). UF6 is a highly corrosive gas that would degrade less resistant materials such as coolants, solvents and rubber. Given the strength of the C-F bond (which is the reason for PFAS persistence in the environment), Teflon® and other liquid fluorocarbons were found to be highly resistant to chemical degradation and corrosion, and therefore, presented a viable solution to the problem at hand.
This represented the first commercial, albeit classified application of PFAS (as Teflon®). After the war, the technology around PFAS was declassified, and widespread commercial application of PFAS began in 1949.