Teflon® is in household products we use every day, from the coatings on our non-stick pots and pans to the stain resistant coating on the clothes we wear, but evidence is coming to light that this miracle chemical is not as safe as DuPont has lead us to believe. Court records and internal documents have shown that DuPont® has been covering up the true dangers of Teflon for decades.
April 6, 1938 was one of those serendipitous moments for Dr. Roy J. Plunkett of DuPont's Jackson Laboratory in New Jersey. It was a moment that all scientists dream of, but few ever experience. Dr. Plunkett, was working with a frozen Freon® related gas chlorofluorocarbon (CFC) sample that he synthesized by reacting tetrafluoroethylene (TFE) (a gas at room conditions) with hydrochloric acid. He was hoping that this CFC could be used as a refrigerant. Jack Rebok, Dr. Plunket's laboratory assistant, removed the canister from dry ice and connected it to the reaction apparatus and attempted to release some of the TFE into a heated chamber, into which he would spray the HCl. When he opened the valve, nothing came out. Plunkett and Rebok inspected the canister and shook it. Nothing seemed to be wrong with it at first. Then suddenly some white powder fell out. They checked all of the cylinders of TFE and discovered that the inside of each was coated with a waxy white coating that Plunkett identified as a polymerized material called polytetrafluoroethylene (PTFE) (1,2). This was a significant finding, because it was generally believed at the time that a chlorinated or fluorinated ethylene could not be polymerized. Attempts to polymerize these materials had failed in the past.(2)
This new polymer seemed almost indestructible and its qualities promised to make it profitable if they could just find the right market. It was patented in 1944 and used first to line equipment used in the enrichment process of U-235 uranium hexafluoride gas for the Manhattan Project during WWII. DuPont reserved its entire output for government use for the duration of the war with about two-thirds of it being used for the Manhattan Project (2).
When the war was over, DuPont had to find a new use for its polymer. In 1953 Teflon was marketed to commercial users, and on December 15, 1960 the T-fal "satisfry" went on sale in Macy's and sold out. Before long almost everybody in the USA and most of the industrialized world was cooking with Teflon lined pans. Teflon products have been made from a variety of polymers, starting with PTFE, the original resin; which was followed by fluorinated ethylene propylene (FEP), introduced in 1960; Tefzel® copolymer of ethylene and tetrafluoroethylene (ETFE) in 1970; and perfluoroalkoxy (PFA) in 1972.
Looking back on the spontaneous synthesis of this miraculous material, one might be tempted to resort to the proverbial warning, "If something looks to be true, it probably is." The physical and chemical properties alone might have been sufficient to make one suspicious. According to Plunkett, "The intriguing substance is thermoplastic, melts at a temperature approaching red heat, and boils away. It burns without residue; the decompositive products etch glass." He also observed that it was insoluble in cold and hot water, Freon 113, ether, acetone, petroleum ether, alcohol, toluene, pyridine, ethyl acetate, glacial acetic acid, concentrated sulfuric acid, nitrobenzene, isoanyl alcohol, sodium hydroxide, ortho dichlorobenzene and concentrated nitric acid. The new substance did not char or melt when exposed to a soldering iron or an electric arc. It wasn't degraded by prolonged exposure to sunlight. It did not rot or swell in a moist environment, and it was impervious to mold and fungus.(2)
Further tests showed that the substance did not char or melt when exposed to a soldering iron or an electric arc. Moisture did not cause it to rot or swell, prolonged exposure to sunlight did not degrade it, and it was impervious to mold and fungus."(2) But, in the 1940s the accumulative property of certain chemicals was not understood. Scientists had yet to deal with the accumulative affects of synthesized chemicals, such as DDT and dioxins.
Footnotes are below.
If you need to cite this page, you can copy this text:
Roberta Barbalace. DuPont's Teflon Cover-up. EnvironmentalChemistry.com. Mar. 22, 2006. Accessed on-line: 6/23/2017