• A microwave is a staple in many kitchens, but it's important to use the correct containers.modern luxury kitchen image by Paul Hill from Fotolia.com
  
  Thanks to the microwave, frozen foods can be cooked or refrigerated foods reheated in fewer than 10 minutes. When using a microwave, it's important to pay attention to the containers you're using to cook the food. Some materials are not microwave-safe and can leach chemicals into food, shatter or release sparks.
  
  

Glass

• Not all glass is created equal, but there is microwave-safe glass. If you have glass containers that are questionable, Cooking for Engineers has a test to determine if your container is microwave-safe. Microwave the container for one minute and carefully touch. If the container is hot, it is not microwave-safe. If its warm, it is fine for reheating. If it is completely cool, it also is fine for cooking. If you try to cook with a non-microwave safe glass container, it could possibly crack or shatter.
  
  

Plastics

• Whether a plastic is microwave-safe depends on its grade and ability to withstand heat. Microwave-safe plastics are food-grade plastics that can withstand high temperatures. When buying plastic containers, food-grade plastic will generally be stored along with other cookware and dishes. Look for microwave-safe on the packaging before trying to cook or reheat food. Microwaving a non-safe plastic container can leach toxic chemicals into your food or drink. Sierra magazine published a report that says non-food grade polycarbonate plastics leach an endocrine disruptor that caused growth problems in mice. According to Cooking for Engineers, there is no evidence that food-grade polycarbonate plastics can leach into food.
  
  

Covers

• In order to prevent splashing or bubbling over, it is sometimes useful to cover food in the microwave. Fully sealing a dish by wrapping or bagging is a microwave cooking method used to steam the food below. It's important to make sure all bags, wraps and papers are microwave-safe. Flimsy sandwich bags or grocery bags can melt into the food. Most brands of white paper towels are microwave-safe, as is wax paper. Never use aluminum foil because it will spark up and could possibly cause a fire.