Today in History – April 6, 1938 – Teflon ® is discovered. In 1938, Du Pont researcher Roy J. Plunkett and his technician Jack Rebok accidentally discovered the chemical compound polytetrafluoroethylene (PTFE) that was later marketed as a commercial product in 1946 under the name Teflon®. Discovery of Teflon® is a good example of serendipity in scientific discovery. Plunkett was researching chemical reactions of the gas perfluoroethylene in order to synthesize new types of refrigerant gases. Rebok found an apparently defective cylinder of this gas and when they opened it found a slippery white powder that had unusual properties – a chemically inert, a very high melting point and low surface friction. He realized it was formed by an unexpected polymerization.

In the beginning, the use of Teflon ® did not “stick” and it took many years to go to market. Although it is sometimes cited as an example of a spin-off from the US space program, its first significant use was in the Manhattan Project, as a material to contain highly-reactive uranium hexafluoride. DuPont sold Teflon ® as a commercial product in 1946 with use in nail polish, plastics, cookware, machinery and wiring.

In recent years, concerns have been expressed about the safety of Teflon ®-coated cookware based on the assumption that toxic substances may be given off when Teflon ® is heated to high temperatures experienced in cooking. However, definitive data supporting this concern appear to be lacking. The U.S. Environmental Protection Agency (EPA) “does not believe there is any reason for consumers to stop using any consumer or industrial related products” which are sold under the Teflon ® brand, and the U.S. Food and Drug Administration (FDA) has found Teflon ® non-stick coatings acceptable for conventional kitchen use.

DuPont supplemented the original Teflon ® with a functionally superior prouct 1n 1976 called Silverstone ®, a three-coat fluoropolymer system that produces a more durable finish than Teflon ®. Its most conroversial use is in Teflon ®-coated armor-piercing “cop-killer” bullets.

Although protected as a registered trademark, the word “Teflon ®” threatens to enter popular usage as a general term describing non-stick surfaces. It has even been applied to public officials who seem immune to accusations of misconduct.

For more information see the Engineering Pathway’s educational resources on teflon ® / polytetrafluoroethylene. For related curricular resources, visit the Chemical, Biochemical, Biomolecular Engineering or the Materials Engineering Education disciplinary communitity.