Everything wears out, regardless of temperature. Sure Teflon lasts a good long time as long as certain temperatures aren't exceeded, but even at room temperature/dishwashing temperature, particles of those molecules are still gonna wear off, and they don't just randomly vanish.

What's that stink you smell out of your vacuum cleaner? Well yeah, lots of dust and dead skin cells and such, but also all the other toxic debris gradually wearing away from our household items and whatnot..