In 1938 a chemist named Roy J. Plunkett opened the valve on a cylinder of tetrafluoroethylene gas in a New Jersey laboratory and nothing came out. The cylinder still weighed as much as a full one, so he and his assistant sawed it in half. Inside was a waxy, slippery white powder. The gas had polymerized into polytetrafluoroethylene, or PTFE, a chain of carbon atoms sheathed in fluorine. Almost nothing reacts with it or sticks to it. It was patented in 1941 and trademarked as Teflon in 1945.

This episode follows that white wax from a failed refrigerant experiment to the Manhattan Project, the kitchen, the operating room, and the courtroom. PTFE sealed the pipes that carried corrosive uranium hexafluoride, and today about half of it insulates wire for aerospace and computing. The finished material is stable in normal use. The trouble lies in the chemicals used to make it, which do not break down and now circulate in the blood of nearly every American.

• French engineer Marc Gregoire coated his fishing tackle with PTFE in 1954, then etched aluminum pans with acid so the coating could lock into the metal, and launched the brand Tefal.
• In 1969 Bob Gore found that stretching heated PTFE creates a membrane with pores far smaller than a water droplet but larger than a vapor molecule, the basis of Gore-Tex.
• Overheated PTFE releases fumes that cause polymer fume fever in people and can kill pet birds, as a 1973 study with parakeets showed.
• After drinking water near a DuPont plant in Parkersburg, West Virginia, was contaminated with PFOA, a science panel studying nearly 70,000 residents linked exposure to six conditions, including kidney and testicular cancer.
• The replacement chemical GenX was found in 2017 in the Cape Fear River, the water supply for about 500,000 people, and is now called a regrettable substitute.