"The blessing and the curse of PFAS is that they’re hard to destroy. These remarkably durable molecules contain super-strong carbon and fluorine bonds that don’t occur in nature. They resist high heat and corrosion. They repel both water and oil.

Chemists created the first PFAS in the 1930s and were quick to put their innovation to use, including in the Manhattan Project, which built the first atomic bomb. By the ’50s the chemicals were becoming key ingredients in industrial processes and mass-produced consumer goods. DuPont used them for its Teflon nonstick pans, 3M for its Scotchgard stain-proofing spray, and food manufacturers for anti-grease packaging. Over the decades, researchers developed a slew of variations—at least 14,000 PFAS exist today, by some definitions—and manufacturers put them in an astonishing range of products, such as raincoats, upholstery, paint, dental floss, and mascara. 

Yet while the chemicals have been a boon for business, they are a bane for nature. Once PFAS get into the environment, they break down only very slowly or not at all, says Natalie Karouna-Renier, a research ecologist at the U.S. Geological Survey (USGS). That means nearly all the PFAS created over the past century are still lingering, in some form, somewhere..."