The microwave oven is perfect for those lazy mornings when you just want to shove last night’s takeaway into your mouth.
But can you reheat the leftovers in the styrofoam (or polystyrene) takeout boxes they give you? Or do you need a separate plate?
Can You Microwave Styrofoam Take Out Boxes?
You shouldn’t microwave styrofoam. It’s not a durable material and it has a low melting point, so it easily breaks down upon heating and can leach into your food.
While it’s unlikely to kill you or even cause any long term damage, it’s a type of plastic that most people would be put off having make its way around your intestines or bloodstream.
Generally speaking, if the container isn’t labeled “microwave safe” then it has not been tested or proven to be safe for humans.
Why Is Styrofoam Not Suitable For Microwaves?
Styrofoam is widely used in packaging hot takeaway food, so you might wonder why we can’t use the same material for hot reheated food.
Styrofoam has not been tested and regulated for microwave use so we can’t be sure it’s safe for humans to eat food that has been in contact with microwaved Styrofoam takeaway boxes.
Moreover, there is evidence to suggest negative health consequences as a result of exposure to Styrofoam, as I’ll expand on in the next section.
The issue with microwave ovens is the way they heat foods.
Have you ever noticed after microwaving food that some parts are burning hot and some are still icy cool? This is fine for most foods as you can let it stand.
But for some containers, this high heat can cause the material itself to degrade and leach into your food.
Is Styrofoam Dangerous?
Styrofoam is a type of plastic with specific properties that make it useful for things like takeaway boxes or food containment.
You can tell a material is Styrofoam from the following symbol, a triangle of arrows surrounding the number “6”. The PS stands for polystyrene as Styrofoam is a trademarked kind of polystyrene.
Styrofoam is a styrene, an umbrella term that encompasses all polystyrene. Evidence, albeit limited, suggests a carcinogenic link due to exposure to styrenes in humans.
The following quote sums things up well.
Polystyrene contains the toxic substances Styrene and Benzene, suspected carcinogens and neurotoxins that are hazardous to humans. Hot foods and liquids actually start a partial breakdown of the Styrofoam, causing some toxins to be absorbed into our bloodstream and tissue
Be safe. Throw your food in a ceramic or glass bowl and enjoy your reheated chicken chow mein with some peace of mind.
What Materials Can I Use In The Microwave?
Glass. This is the safest all round microwaveable material. The radio waves (or microwaves pass) straight through the glass and there is no risk of undesirable chemicals leaching into your food.
Ceramic. Ceramic containers are a safe bet for microwaving foods for the same reason as glass with one caveat, they have a high heat capacity. Watch out for ceramic bowls or plates that get heated by convection by the hot food – careful not to burn your hand or drop the dish!
Plastic. Plastics are a good material for the microwave in the sense that the radio waves are not absorbed, but it’s a big risk for leaching into your food, particularly the infamous BPA plastics. Use containers that have a “microwave safe” label to be sure they have been tested for human consumption.
Metal. Never put metal into your microwave. The unique properties of metals cause dangerous build ups of energy and can cause literal sparks to fly.
Can I Microwave Food On The Glass Turntable?
The convenient option of putting your leftover pizza on the glass turntable inside the microwave does work, but it’s inadvisable.
Without a container, your food may pop, splatter or stick to the turntable or other parts of your microwave. Bacteria and other harmful pathogens then have the opportunity to grow so the next time you (or someone else) uses the microwave you run the risk of cross-contamination.
On the other hand, if you’re willing to wash the turntable right after then go straight ahead.