Although the microwave has saved a lot of time, many people have voiced concerns about its safety. Microwaves shoot electromagnetic radiation into food to heat it. Unfortunately, many items don’t respond well to that radiation.
Certain foods may explode in the microwave. Even mostly safe materials, such as styrofoam, may start a house fire if you warm up the wrong variety. Before you put objects into the most common kitchen appliance, learn what isn’t safe, clean, or practical to warm up in the microwave.
Microwaving aluminum foil is a recipe for a fire hazard. The small electric fields spark through the foil, which may catch fire. Never put a large amount of aluminum foil in a microwave.
According to the USDA, it’s safe to put a small amount of aluminum foil in the microwave to “shield” parts of food from heat. But don’t cover more than 1/4 of the food, and make sure your foil isn’t wrinkled. Creases in foil can cause arcing, which creates sparks.