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

Fact: Plastic containers and wraps labeled as safe for use in the microwave don't pose a threat.

There is some evidence that plastic containers that aren't intended for use in the microwave could melt and potentially leak chemicals into your food. Avoid microwaving plastic containers that were never intended for the microwave, such as margarine tubs, takeout containers or whipped topping bowls.

Check to see that any container you use in the microwave is labeled as microwave-safe.

Culled Mayo Clinic