Plastics and Microwave Cooking
There has been a widely circulated e-mail warning against using plastic containers and plastic wraps in the microwave oven. The warning suggests that plastics can contaminate foods with dioxins when heated in the microwave.
Cornell University’s Department of Food Science has researched the literature on the claims made by the e-mail and found no new studies or reviews that support the allegation that there are newly discovered dangers from using plastics in the microwave.
The FDA carefully reviews the substances used to make plastics that are for food use. There are provisions under the Federal Food, Drug and Cosmetic Act that any food additive or new substances used to make plastic for food use are classified as “food contact substances”. These must be found safe for the intended use before they can be marketed by the manufacturer.
Edward Machuga, Ph.D., a consumer safety officer in the FDA’s Center for Food Safety and Applied Nutrition says that “It’s true that substances used to make plastics can leach into food. But as part of the approval process, the FDA considers the amount of a substance expected to migrate into food and the toxicological concerns about the particular chemical.” The regulated plastics have been assessed and have been found to be within the margin of safety and the FDA will revisit a safety evaluation if new scientific information raises a concern.
Claims have asserted that dioxins, a group of contaminants labeled as a “likely human carcinogen” by the Environmental Protection Agency are contained in plastics. Machuga says “The FDA has seen no evidence that plastic containers or films contain dioxins and know of no reason why they would.
As a consumer, it is important to know what is intended for microwave use. Plastics should be used for their intended use. There should be instructions for microwave use on containers used for this purpose. If not, change to a different container or plate. These containers are made to withstand high temperatures.
Examples of containers that are inappropriate for microwave use are carryout containers from restaurants, margarine tubs, whipped topping bowls and containers that hold prepared microwavable meals after you use them. The containers holding microwavable meals are meant for one time use. Do not use thin plastic storage bags, brown paper or plastic grocery bags, newspapers or aluminum in the microwave.
Items that should be safe to use in the microwave oven are microwave plastic wraps, wax paper, cooking bags, parchment paper and white microwave safe paper towels. Do not let the plastic wrap touch foods during microwaving.
Always read directions on the products you use in the microwave oven. Cover your food to help prevent against contamination, keep moisture in, and allow food to cook evenly.