The U.S. Food and Drug Administration regulates microwave ovens. The FDA sets and enforces performance standards for microwave ovens to assure radiation emissions do not pose a hazard to public health. When you use a microwave oven, you should use it properly and maintain it appropriately, as recommended by the user manual. Read more for tips on safe use.
Read more at: http://www.fda.gov/consumers/consumer-updates/5-tips-using-your-microwave-oven-safely