The critical point is whether we studied PFAS _before_ it was used extensively. I may be wrong but to my knowledge of historical chemical production is that we

The critical point is whether we studied PFAS _before_ it was used extensively. I may be wrong but to my knowledge of historical chemical production is that we generally use a chemical for a long time before we do extensive research into safety. PFAS is kind of unique because it is politicised: there are lots of groups who claim harm and therefore don’t want to look at the science skeptically. And if harm actually exists, governments want to reduce liability so are happy to ignore any signs of harm before a cheap solution becomes available.