Is microwaving foods in zip lock bags safe, or will chemicals leach into the food?

[astro]

If I microwave frozen spaghetti sauce to piping hotness inside the plastic bag I froze it in originally, will plasticizers and other chemicals used to make the plastic bag leach into the food if the food is boiled inside the bag? .

[ouryL]

They taste bad. I tried this with cheddar brots. But since they do now sell microwaveable bags, buy them instead.

[CookingWithGas]

I don’t know about microwavable bags, that’s a new one on me, they might be fine. Conventional bags might be able to handle boiling water but tomato sauce boils at a higher temperature than water and I have ruined a plastic container like that; a conventional plastic bag probably wouldn’t survive it.

[BrandonR]

Microwaving in Ziploc bags appears to be safe according to the Ziploc website:

@Ziploc.com

Ziploc® Brand Sandwich Bags and Snack Bags should not be used in the microwave because they are too thin. Ziploc® Brand Storage Bags may be used for microwave reheating; Ziploc® Brand Freezer Bags may be used for microwave reheating and defrosting. When defrosting or reheating, always open the zipper one inch to vent. Be careful when reheating foods that are high in fat or sugar content (bacon, pastries), because these foods reheat very quickly and may exceed the softening point of the bags.

Ziploc® Brand Zip ‘n Steam™ bags are specially designed for microwave steam cooking. They are made of two layers of plastic laminated together that are formulated to stand up to the high temperatures of cooking in the microwave, so they will not get soft and flimsy. When pressure builds up in the bags, specially designed vents allow it to escape. Always allow the bag to stand for one minute before handling. When opening, hold the top of the bag, as the blue area above the zipper remains fairly cool to the touch, and open the bag away from your body to allow the hot steam to escape.

But it does go on to say that the bags should not be used for boiling becuase of the “extreme heat” which leads me to believe they don’t fare the temps. There are some other handy Safety-related FAQs on http://www.ziploc.com that may be of interest in helping you choose a suitable storage device for future endeavors. They do mention that Ziploc bags are 100% Dioxin free.