Most of the time the food came in that very plastic. I mostly sous-vide meat that came frozen and is already vacuum sealed. One less step.

You're generally heating it to 140 F or so. I don't know if that's sufficient to trigger leaching of some sort, but the plastic isn't deformed in any way and there's no aftertaste.

Any experts care to weigh in?

Is there any scientific evidence for this statement on no harmful chemical transfer below 140F. Also, just because the food came in the very bag you're cooking it in doesn't mean it is safer.

> Is there any scientific evidence for this statement on no harmful chemical transfer below 140F.

I didn't make that statement. I simply stated that was my practice. If you have evidence that it is harmful, I would certainly like to know.

> Also, just because the food came in the very bag you're cooking it in doesn't mean it is safer.

Absolutely. There is no evidence that it doesn't leach at room temperature. Should we stop buying all food packaged in plastics? That's a tall order. Many vegetables come in plastics now and those that don't, you'll likely put in a plastic bag either in the grocery store or as you're leaving it.

Do you have evidence that any of this is harmful? Genuinely want to know.

I don't know much about sous-vide, but the cooking temperature is 55 to 60 degrees celsius. That's fairly low. Most plastics shouldn't deteriorate at that temperature.

You can safely microwave food in certain types of plastic - sous-vide cooking is far lower temperature.

But the initial premise is unfounded. Some of the most toxic chemicals occur naturally.

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.

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.

When you cook sous vide you buy bags made specifically for the purpose. Bags made of polyethylene or polypropylene are the most common. For more info see http://modernistcuisine.com/2013/03/is-it-safe-cook-plastic/