EPA is telling us its PFAS
“In the 1950s, 3M was able to use these processes to begin manufacturing various PFAS, including PFOA and PFOS—two types of PFAS—for product applications. In the 1950s, 3M launched several products based on PFAS, including Scotchgard™.”
https://www.3m.com/3M/en_US/pfas-stewardship-us/pfas-history/
That’s about 45-50 years before rates started to rise.