[ha292]

I am not worried about natural toxins. Most of what I select to eat is likely free of them. What I am worried about is that there doesn't seem to be any evidence of non-transfer of chemicals even at lower temperatures. I see claims but no clear evidence. Even if the transfer rates are low the chemicals "dose" can accumulate over repeated use.

[nichtich]

You have to realize even if your "natural" food is free of toxins, the traditional cooking methods are likely to produce them, especially in grilling, frying and baking. And the worse part is the chemistry there is complex and may differ depend on source material and actual cooking method. On the other hand, the plastics are simpler and easier to analysis of possible transfers(or changes) in given temperatures. For the types approved for microwave uses there are more research done than say the interaction between beef and your pan. So I wouldn't worry too much about it.