Good morning, everyone -
Interesting topic. I'm no expert, but I try to get my info directly from the experts, rather than from "send this to everyone you know" Internet messages.
If you go to
www.ziploc.com and rummage around, you find three things.
1. There is no mention anywhere of boiling food in ziploc bags - good or bad.
2. There are lots of questions about whether ziplocs contain hazardous substances like dioxins or BPA that could be released by heat. In each case, ziploc says "No", and specifically asks you not to believe the "send this to everyone you know" Internet messages.
3. In several places, it is said that microwaving food in a ziploc bag is perfectly fine, and is recommended.
Why is this last point significant? As you know, the temperature of anything immersed in boiling cannot get any hotter than the water itself, and the temperature of boiling water is 212 degrees - never hotter.
On the other hand, the temperature inside a microwave oven can get LOTS hotter than 212 degree. How do I know? Popcorn won't pop at 212 degrees, for instance, and a turkey won't roast at 212 degrees - but microwaves do both things quite nicely.
Of course you don't do popcorn or turkeys in ziploc bags - but the point is that a microwave oven can heat up anything you put inside it to temps much higher than 212 degrees.
And although most people don't use it, most larger microwaves come with a plug-in temperature probe that let you set temps up to 450 degrees, just like a regular oven.
So anyway, I'm having trouble with the idea that a ziploc can be hazardous at 212 degrees, but is OK at 450 degrees or more.
Just my 2cents.
Bill