If you want to use your microwave safely, some types of Styrofoam can be microwaved. You’ll have the best luck when they’re labeled “microwave safe” or at least indicate whether it is or isn’t by looking for something like this on the package itself (though it may say “CLASS I DEVICES NOT SUITED FOR USE IN A MICROWAVE OVEN); if not sure what kind of foam has touched electricity feel free to stay away from any type of conventional oven as well!