Well, as person who has worked for one of the largest pan manufacturers in Europe I can say this: NONE of the manufacturers recommend that you heat your PTFE cookware over 250C. Beyond this point the sprayed coating normally starts to peel off. Getting your cookware to 280C without the coating coming off is an accomplishment... Most people would turn their stoves down anyway when the coating starts coming off... I think. PTFE needs to get way over that 280C point to start releasing fumes. As long as you are not boiling your PTFE coating, you are fine.