Q. For convenience, I sometimes like to use the microwave reheating leftovers on a foam plate or in the foam container that I purchased from my favorite take-out restaurant. It seems to work fine for me, but I am curious if this is a safe method for heating food and how best to do this. My question is: Can you microwave foam plates and is it a safe method for reheating food?
A. There answer isn’t a definite yes or no answer to this question. Polystyrene foam is a popular, disposable material used for serving and packaging a variety of foods. It can be a finicky material when it comes to exposing it to heat. So, let’s explore the properties of foam plates and how best to safely use them to heat food in a microwave oven.
What is Polystyrene Foam?
Polystyrene foam is a lightweight material that has great insulating properties to retain or keep in heat. It is commonly used to make building insulation, packaging peanuts, coffee cups, take-out containers, and dining plates. It is also used to make flotation devices for pools and boats. The material is very popular for food containers because it is inexpensive and can keep food and beverages warm for some time.
In recent years, foam containers and plates have been banned in certain urban areas due to potential health and environmental concerns. Studies have been conducted on the styrene in foam as a potential cancer causing compound in animals and humans. Some foam products are difficult to recycle because they don’t break down easily in the environment. Polystyrene foam can build up in landfills.
Can You Microwave Foam Plates and How?
There is some concern surrounding heating food on foam plates in the microwave. The compounds used in the manufacturing of polystyrene foam have the potential to leach into your food when heating them. This is especially true when you are reheating fatty foods, such as meats and cheeses.
That said, the Food and Drug Administration (FDA) does allow for foam plates and other food related products that have been deemed microwave-safe through testing to be used in a microwave. These plates will be labeled as such. Always look for a designation on the packaging of the plates that indicates they are microwave-safe when purchasing them.
While I have reheated coffee in a foam cup successfully, I don’t do it for more than 30 seconds to 1 minute. Reheating in a foam container at high heat for a longer period of time could result in the container or plate actually melting. This results in a terrible mess and possible contamination of the food. Keep in mind that this material is a good conductor of heat, so use caution and check the plate often. If the microwave is lacking a rotating turntable, rotate the plate and stir the food halfway through the heating process.
When using a foam plate in the microwave, be very careful when removing it. It can get pretty warm and possibly pliable or flimsy for a few seconds.
Some Final Thoughts
Foam plates are good insulators that will keep your food warm for a good bit of time. They are also convenient if you don’t have time to wash dishes. While you can microwave your food on a foam plate, you must be mindful of the heat and timing so that the plate does not melt. Always purchase plates that are labeled as microwave-safe if using them to heat your food. Otherwise, heat the food in a glass or microwave-safe ceramic container and transfer the food to a disposable foam plate for serving.