> But at least it's almost completely inert (unless overheated), which makes it much less likely to be harmful than substitutes.

I don’t think that’s a strong argument. Asbestos is quite inert, and that is what makes it so harmful. A fiber will, over time, harm more and more cells.

Teflon isn’t a sub-cellular sized needle though.

Probably breaks down to shorter chain PFAS

https://chemsec.org/the-teflon-chemical-ptfe-is-often-touted...

Although it is claimed that very little migrates to food

https://www.fda.gov/food/process-contaminants-food/authorize...

The monomer used to make it is considered "probably carcinogenic"

https://en.wikipedia.org/wiki/Tetrafluoroethylene#Safety

so occupational exposure at the factory and environmental release are concerns.

> The monomer used to make it is considered "probably carcinogenic"

Yeah, this is what I heard before. That the coating itself isn't so bad, but the manufacturing process produces stuff that is awful enough that we probably shouldn't use it.

"overheated" seems to be doing a lot of work here. It's extremely easy to heat a teflon coated pan to the point where it becomes harmful. Teflon flu isn't good for humans and is absolutely fatal to birds. Non-stick cookware releases toxic gases at typical cooking temperatures. https://pubmed.ncbi.nlm.nih.gov/28913736/