Can You Microwave Styrofoam? Things You Must Know

It can be difficult to know when it’s possible to microwave a certain material or not. Sometimes certain packages aren’t marked clearly, so you have to guess if they can be microwaved or not. Lots of things are packaged in Styrofoam, so it’s good to know a bit about this material.

The question of whether Styrofoam is microwavable is somewhat debatable, especially if you know nothing about Styrofoam. This confusing substance may, on the surface, seem like it would be easy to microwave. But at the same time, it may seem illogical to microwave it.

Styrofoam is a somewhat bewildering packaging material for these reasons, but don’t be deterred by this! Just because your favorite foods are packaged in Styrofoam containers doesn’t mean that you can’t enjoy their convenience. Check out the information below!

Can You Microwave Styrofoam

What is Styrofoam?

Polystyrene foam is a petroleum byproduct. The term “Styrofoam” refers to any polystyrene foam material in any form, though in popular culture it usually refers specifically to a particular type of food packaging that’s extremely popular.

Styrofoam is a brand name, like Kleenex or Chapstick, and as such the actual composition of Styrofoam deserves a fair explanation. The simple and short way of explaining is that Styrofoam is made of polystyrene foam, a material that’s also used in home insulation.

While it might seem scary that something that stores food products is also used to insulate houses, don’t let this deter you. Styrofoam created for food products is perfectly safe and is designed to meet the appropriate health standards of food safety.

So, what is polystyrene foam, exactly? Polystyrene is a hydrocarbon polymer that comes from a monomer referred to as styrene. Because this material is a petroleum byproduct, it isn’t that great on the environment.

Styrofoam is extremely difficult to break down. In fact, once disposed of Styrofoam packaging can take hundreds of years to degrade entirely! Styrofoam is used in many contexts, and the toxic chemicals used to stabilize and form the plastic can also take an environmental toll.

Polystyrene foam is extraordinarily versatile though and can be used in a number of different capacities. From its uses in the world of food as a packing substance to its role in construction as a reliable insulator, Styrofoam is a pretty amazing substance.

Despite its extreme versatility, Styrofoam still has its limits. People who buy Styrofoam containers of food should be aware that some Styrofoam containers are microwaveable, while others are not. Read on to learn more about Styrofoam safety!

Can You Microwave Styrofoam?

It’s important to be careful when microwaving different materials, because some are safe to microwave, and others are not. This is especially true when it comes to Styrofoam, because there are actually two different kinds of Styrofoam and it’s difficult to tell them apart!

Styrofoam is a type of soft plastic. This of course demystifies some of the reasons why it’s necessary to check and make sure that the Styrofoam is indeed microwave safe. Some plastics are microwave safe, while others simply are not.

The question of microwaving Styrofoam is one that almost everyone has, so there’s no need to be embarrassed if you’re asking yourself this question. It’s an important thing to ask! And, because Styrofoam comes in two kinds, it’s a fair thing to wonder about.

The first kind of Styrofoam can be microwaved, and it’s perfectly safe to microwave this type of Styrofoam. Often, microwaveable food items will be packaged in Styrofoam containers that will be safe to microwave, but it’s still a good idea to check and see if there’s any labeling.

The second kind of Styrofoam is NOT safe to microwave! Because this Styrofoam type is made from polystyrene foam, which is a petroleum byproduct. By microwaving this type of Styrofoam, you can end up releasing toxic chemicals into your food or even melt the Styrofoam entirely.

Styrofoam starts to decompose when it reaches temperatures of approximately 200 degrees Celsius (392 degrees Fahrenheit). But Styrofoam can start to change states at as low as 100 degrees Celsius (212F), meaning that at this point toxic chemicals can leak into food.

The vast majority of Styrofoam falls under the second category of being NOT microwave safe. However, if a Styrofoam container has been labeled as safe, then it’s fine! The FDA rigorously tests Styrofoam product containers to ensure that they can be safely microwaved.

The FDA has dictated a specific, designated level of plasticizers that are safe for human consumption. This level is 100-1000 times less (per pound of body weight) than the amount that was shown to harm lab animals. Only Styrofoam that meets this condition is microwave safe.

When the testing is done, the FDA tests the Styrofoam container under various possible circumstances to ensure that it is indeed safe. Estimates are made in regard to the time that a product would be microwaved, how often the container will be used, and other matters.

It’s important that you absolutely DO NOT microwave food in a Styrofoam container that has not explicitly been labelled as microwave safe. This can cause the food to be ruined, but besides that, it can also cause serious health damage should you accidentally consume toxins.

If you’re not sure if a Styrofoam container is microwave safe, the smartest thing to do is to transfer the food or drink to a container that is for sure microwave safe. This way, you avoid potential health risks and you can safely and happily enjoy a hot meal with no danger.


In a world with so much Styrofoam and plastic, the question of whether or not a food container is microwaveable is a vital question. We know that Styrofoam may not be able to go into the microwave, but at the same time we know that the question of more complicated than it seems.

With so much variation among types of packaging containers, it’s always a good idea to check and see if a container is microwaveable before sticking it in the microwave. This is especially true with Styrofoam! A quick look at the packaging makes a dramatic difference for your health.