On the morning of April 6, 1938, a young DuPont chemist named Roy Plunkett had his assistant crack open a cylinder of gas they’d used the day before. Nothing came out. No hiss, no rush of pressure, nothing. That alone wasn’t strange—except the cylinder still weighed exactly what it should if it were full.
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Gas doesn’t just disappear. So Plunkett did the only sensible thing: he had the valve sawed off and tipped the cylinder over. Out slid a scoop of white, waxy powder. He was 27 years old, two years out of his Ph.D., and he was looking at what would become one of the strangest and most useful materials of the 20th century—though at that moment, all he had was a ruined refrigerant experiment and a weird lump of solid.
Quick answer
Teflon (PTFE, or polytetrafluoroethylene) was discovered by accident on April 6, 1938, when DuPont chemist Roy Plunkett found that a cylinder of tetrafluoroethylene gas had spontaneously turned into a solid white powder overnight, seemingly making the gas ‘vanish’ from the container.
A refrigerant experiment gone sideways
Plunkett wasn’t trying to invent anything revolutionary. He’d joined DuPont’s Jackson Laboratory in Deepwater, New Jersey in 1936, and his job was to find safer refrigerants—chlorofluorocarbons, the chemistry of the moment, meant to replace toxic gases like sulfur dioxide and ammonia in home refrigerators. As part of that work, he’d manufactured about 100 pounds of tetrafluoroethylene (TFE) gas and stored it in small pressurized cylinders packed in dry ice, planning to react it with hydrochloric acid.
On that April morning, Plunkett and his lab assistant, Jack Rebok, set up one of the TFE cylinders to run the next step of the experiment. They opened the valve. Nothing happened. Given that TFE is a gas under pressure, this should have been impossible unless the cylinder was empty—but weighing it proved otherwise. It still had its gas-filled weight. Something had happened to the TFE that nobody expected, because at the time, chemists didn’t think TFE could polymerize at all.
The powder nobody ordered
Plunkett had the valve removed and turned the cylinder upside down. A whitish, waxy solid fell out onto the workbench. Instead of shrugging it off as a ruined batch and moving on—which many chemists in his position might have done, since it wasn’t what he was being paid to find—Plunkett got curious. He ran tests on the mystery substance and found it was almost unbelievably inert: acids didn’t touch it, solvents didn’t dissolve it, heat barely bothered it, and almost nothing would stick to its surface.
What had happened, chemists later confirmed, was that the fluorine and carbon atoms in the TFE gas had linked together into long, tightly bonded polymer chains under the pressure and cold of the cylinder—forming polytetrafluoroethylene, or PTFE. DuPont patented the polymer (Plunkett’s patent application was filed in 1939) and, in 1945, trademarked the material as Teflon.
The part most people miss
Teflon’s first real job had nothing to do with kitchens. During World War II, the material was classified and funneled straight into the Manhattan Project, where its extreme resistance to corrosive uranium hexafluoride gas made it essential for seals and gaskets in the gaseous diffusion process used to enrich uranium. The public didn’t hear the word ‘Teflon’ until years later. Nonstick cookware didn’t arrive until the 1950s, pioneered commercially by French engineer Marc Grégoire, whose company Tefal began selling Teflon-coated pans in France in 1956; American cookware followed by the early 1960s. It’s also worth separating two things people often blur together: PTFE itself (the actual nonstick coating) is chemically stable and considered safe for cookware, but for decades it was manufactured using a separate processing chemical called PFOA, one of the ‘forever chemicals’ now linked to serious health and environmental harm. DuPont phased PFOA out of Teflon production by 2013—a real controversy, but a different chemical from the one Plunkett found in his cylinder.
Sources
Science History Institute, biographical profile of Roy J. Plunkett, detailing his background, the 1938 discovery at DuPont’s Jackson Laboratory, and Teflon’s path from refrigerant research to nonstick cookware.
Wikipedia entry on Roy J. Plunkett, cross-referenced for dates (born June 26, 1910; April 6, 1938 discovery; 1936 Ohio State Ph.D.), assistant Jack Rebok’s name, and Plunkett’s later career and honors including the National Inventors Hall of Fame.
Additional reporting drawn from The Chemical Engineer’s history of PTFE and coverage of the PFOA ‘forever chemicals’ controversy, used to confirm the Manhattan Project application, the Tefal/Grégoire cookware timeline, and the distinction between PTFE and PFOA.
Explore more: more accidental inventions.
Teflon FAQs
Who invented Teflon and when?
DuPont chemist Roy Plunkett discovered it by accident on April 6, 1938, while researching refrigerants at the company’s Jackson Laboratory in New Jersey.
Why did the gas seem to disappear?
The tetrafluoroethylene gas hadn’t vanished—it had polymerized into a solid white powder (PTFE) inside the pressurized cylinder, which is why the container kept its original weight even though no gas came out.
Was Teflon used for nonstick pans right away?
No. It was first used for wartime industrial purposes, including seals in the Manhattan Project’s uranium enrichment process, and didn’t appear in cookware commercially until the mid-1950s in France and the early 1960s in the U.S.
Is Teflon the same thing as the ‘forever chemicals’ in the news?
Not exactly. PTFE, the nonstick material Plunkett discovered, is considered chemically stable. PFOA, a separate chemical once used in manufacturing PTFE, is the ‘forever chemical’ linked to health risks, and DuPont phased it out of Teflon production by 2013.
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