Plastic containers in the microwave: A cause of cancer?

content provided by

Plastic containers in the microwave: A cause of cancer?


Is it true that you shouldn't use plastic containers to reheat foods in the microwave because the plastic gives off harmful substances?

No state given


Stories have circulated for years that plastics leach harmful chemicals into microwaved foods. There is some evidence that small amounts of substances used to make certain plastics can leach into some foods. However, the Food and Drug Administration (FDA) has evaluated this issue and found that leached substances pose no threat to a person's health.

Other claims have suggested that plastics contain dioxins, a group of contaminants labeled as a "likely human carcinogen" by the Environmental Protection Agency. But according to the FDA, there is no evidence that plastic containers or wraps contain dioxins.

The FDA carefully reviews substances used to make plastics designed for food use, including microwave-safe plastic wraps and containers. These plastics are classified as "food contact substances." The FDA must find them safe for their intended use before these products can be marketed as such.

To ensure the safe use of plastic containers or wraps when microwaving food, the FDA recommends the following:

  • Use containers and materials that are specifically labeled as microwave-safe. Margarine tubs and carryout containers from restaurants shouldn't be used in the microwave. Discard containers that hold prepared microwaveable meals after you use them because they're designed for one-time use.
  • Check the label on packaged foods. If you don't find instructions for microwave use, use a different plate or container that you know is microwave-safe to heat the food.
  • If you cover food in the microwave, use glass or ceramic covers, microwave-safe plastic wraps, wax or parchment paper, or white microwave-safe paper towels. Be sure to loosen the wrap or lid to allow steam to escape.
  • Microwave-safe plastic wrap should not directly touch the food. The labels on some plastic wraps recommend that there should be a 1-inch space, or greater, between the plastic and the food during microwave heating.
  • Don't use thin plastic storage bags or plastic grocery bags in the microwave.

Last Updated: 07/24/2006
© 1998-2016 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.

Terms and conditions of use


Bookmark and Share   E-Mail Page   Printer Friendly Version