If you’re a freak for takeout, you’re no stranger to eating out of Styrofoam. In fact, you probably chuck that same Styrofoam in the microwave whenever you’re hungry for leftovers. But can you microwave it safely, or are you unintentionally speeding up your death?
Styrofoam is a trademarked brand of polystyrene foam, which is regularly used for building. But we also use the term to describe another type of expanded polystyrene foam used for takeout containers, coffee cups, packing peanuts and other single-use products that are awful for the environment. (As an aside, cities like Seattle and San Francisco have banned expanded polystyrene due to its environmental footprint.)
The one concern when microwaving products made of polystyrene is a chemical compound they contain called styrene, which has been linked to cancer in both human and animal studies. As other studies have discovered, when you microwave containers made of polystyrene, chemicals like styrene can leak into your food. This is especially true for foods that are high in fat, like meats and cheeses.
However — and this is a big however — the FDA regulates polystyrene containers by testing their use in microwaves and labeling the ones that pass as “microwave-safe.” Therefore, if your Styrofoam container sports that label, you can safely zap it, according to the food and drug dudes. Otherwise, you’re venturing into the unknown.
It’s also worth noting that polystyrene containers that have scratches or cracks — say, you got feisty while forking your chow mein — have a greater potential of leaking possible harmful chemicals.