We have some plates we bought from Target a few years ago that we frequently use in the microwave. These plates are listed as not being microwave safe.

Does that mean that they could cause health issues if we use them in the microwave, or does that just mean that the microwave could ruin the plates?

  • I wouldn't say "it just means that the microwave could ruin the plates" - if the microwave potentially ruins the plates, you're potentially melting plastic into your food. It probably won't taste good, and I'm pretty sure you're not supposed to eat your plates.
    – Cascabel
    Commented Dec 19, 2013 at 17:46
  • Could they be made of melamine? This is a plastic which is used quite often for plates and other food utensils. It does melt or otherwise change its appearance in the microwave. But it releases formaldehyde in the microwave, which makes it very toxic.
    – rumtscho
    Commented Dec 19, 2013 at 22:43

3 Answers 3


Yes, there are risks. Avoiding those risks is the entire point of the microwave-safe labeling.

When plastic is marked as microwave-safe (in the US), it means that the material has been tested and found not to release harmful chemicals when heated, by FDA guidelines. This is a stronger assertion than just that it doesn't melt. Something that's unsafe in the microwave may not show it visibly; it may leach chemicals without melting.

It's entirely possible that something not marked as microwave-safe may actually be safe, and just not be tested. But you have no way to know, and you should assume that anything unmarked could potentially be harmful.


There are two main reasons a plate could be labeled as not suitable for use in a microwave:

  • It is made (at least partially) from materials that absorb microwaves, so that it will heat up during microwave use. This is generally considered a bad thing in microwave cookery and can lead to burns if you touch the plate with your hands, as well as melting or warping of the plate.

  • It is made from materials which are not food safe when microwaved, due to off gassing or whatever other reason. It may leave a harmful substance in the foods.

In the US to be labelled microwave safe, the item must be tested by the FDA. Failure to display that label does not mean it is unsafe necessarily; it may not have been tested.

Either way, it is not a good idea to use a plate which is not microwave safe in the microwave. Only use known microwave safe plastic items.

See also: Harvard Health, Microwaving food in plastic: Dangerous or not?

  • Your first point is most prevalent. Most plastics used in food grade item do not release harmful gases when cooked, but they do break down
    – TFD
    Commented Dec 20, 2013 at 9:45
  • 1
    I wouldn't be so certain that the first point is most prevalent. Melamin is frequently used in food utensils, and it releases something nasty in the microwave (it was either formaldehyde or a relative of it, IIRC)
    – rumtscho
    Commented Feb 13, 2015 at 16:05

I once had a cheap Chinese plastic bowl explode in my oven shattering my glass turnstile not to mention my nerves. It is just not worth risking your oven or your health by not using microwave safe equipment. Glass is always a safe bet and is not expensive.

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