Damn it, autocomplete. Alk_a_nes, not alkenes.

PFAS only describe one part of the overall molecule. It doesn't necessarily tells if the rest of the structure is toxic or not. It's like saying "I though canine were dangerous?" (yes for big cats, no so much for your average French bulldog).

Also, the dose makes the poison, etc.

It's somewhat unclear, but given that they've been found in every piece of human tissue tested for it, I'd say at the very least it kills slower than HIV. Of course there are many different kinds of PFAS, some might be worse than others.

‘PFAS toxic’ is about as sophisticated as saying ‘Nuclear bad’.

Western society isn’t scientifically literate enough to develop these things at the moment, so they will happen in APEC for now.

Most vaccines have had some toxic component in them particularly historicaly. If you look up different vaccine types over the past 50 years you'll see often ingredients are removed or replaced because of it. The general wisdom is that it's either small enough quantities that you'd have less negatives from the toxicity than you have from being able to prevent the disease at a population level.