In a comment to the best answer to question 582, Muhd writes: "I would add that it is also unhealthy if you microwave in something that is not microwave safe as toxic chemicals could migrate into the food from the container (e.g. from most plastics)."

Is there any evidence for this?
Are some plastics more dangerous than others?



Microwaved plastics do not cause cancer.

Can I microwave food in plastic containers or covered in plastic film?
There is no scientific evidence that microwaving food in plastic containers or wrapped in clingfilm can affect the risk of cancer.

Plastic bottles - Cancer Research UK

Claim: Research has proved that microwaving foods in plastic containers releases cancer-causing agents into the foods.
Status: False.

Plastic-Tac-Toe - Snopes.com

Myth: Microwaving plastic containers and wraps releases harmful, cancer-causing substances into food.

Fact: Microwave-safe plastic containers and wraps are safe to use in the microwave.

Cancer causes: Popular myths about the causes of cancer - Mayo Clinic

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    You had me till that third quote. "Microwave-safe plastic containers" would seem to imply that there are "microwave-unsafe" plastic containers as well. – Kyralessa Jul 4 '12 at 22:58
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    @Kyralessa: "Microwave-safe" plastics are designed not to melt in the microwave. It has nothing to do with what's being discussed here. – BlueRaja - Danny Pflughoeft Jul 5 '12 at 3:15
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    The question seems to ask mainly about toxicity but your answer focuses only on cancer. There are a lot of ways for something to be toxic without having to cause cancer. – DQdlM Jun 11 '13 at 16:25
  • "Microwave-safe plastic" is referring to, in my interpretation, the ability of the container to resist the heat (and survive the process unscathed), as much as it is referring to the safety of the consumer. This makes complete sense when you see a non-microwave-safe plastic container warp and melt after one burst in the microwave. – Highly Irregular May 12 '14 at 3:37

pthalates and BPA, both proven carcinogens, are both ingredients of food-grade, microwave-safe plastic food storage containers (same source). Experiments done in the 1990's that even at room temperature, plastics aren't inert — they leach into the materials they contain in tiny amounts, but enough to act as hormone mimics. If you heat such a food container, the microwave radiation makes the molecules of the container move require heats all the molecules it touches, carcinogenic plastic included.

Even the snopes.com article "Plastic-Tac-Toc," used to refute the idea that plastics leach carcinogenic chemicals when heated has this quote from Dr. Rolf Halden of the Johns Hopkins Bloomberg School of Public Health:

In general, whenever you heat something you increase the likelihood of pulling chemicals out. Chemicals can be released from plastic packaging materials like the kinds used in some microwave meals. If you are cooking with plastics or using plastic utensils, the best thing to do is to follow the directions and only use plastics that are specifically meant for cooking. Inert containers are best — for example, heat-resistant glass, ceramics and good old stainless steel.

Why Halden failed to note that plastics that are specifically meant for cooking include carcinogens is anybody's guess.

Get rid of plastic food containers, and especially don't re-heat foods they contain in the microwave.

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    You have no citations for anything in this answer. Is there any research backing any of this? – John Lyon Jul 4 '12 at 23:35
  • The reference to carcinogenicity is not to a reliable or trustworthy source. "Our Stolen Future" is a contentious rant that doesn't attempt to give a disinterested scientific overview of the issues behind the safety of chemical traces. – matt_black Jul 10 '12 at 10:05

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