Styrofoam is an easily molded material used to make a variety of products, including food containers, plates and cups. Although Styrofoam has a different appearance and texture, it is actually a category of plastic. A common myth, according to the Harvard Medical School, is that plastics and Styrofoam cannot be used in the microwave because the substances will melt into food and make it toxic. Although traces of plastic do end up in the food, they are microscopic amounts that are not dangerous. If you follow safety protocol correctly, you can use Styrofoam in the microwave.
Inspect the Styrofoam container for any signs of damage, such as cracks or rips. Turn the item over and ensure that the bottom does not state it is not safe for microwave-use. If the item is damaged or marked unsafe for microwave, discard it immediately.
Position your food or drink inside the Styrofoam container or cup or place it directly onto a Styrofoam plate. Ensure the Styrofoam does not cover or touch the top of the food or beverage.
Fold back the lid of a Styrofoam container to keep it open or cut it completely off if you don't have room in your microwave for the lid to remain folded back. Drape a paper towel across the top of the Styrofoam if you need to prevent splatters.
Set your microwave to 50 percent power or "medium" and heat your food until it is warmed through. Watch the Styrofoam as the food cooks and remove it immediately if the Styrofoam starts to become misshapen or has holes in it--this is a sign it is starting to overheat and is at a higher risk of leaking additional plastic into the food.
Serve the food directly out of the Styrofoam if you desire. Discard the container, cup or plate immediately after using it.