Can You Microwave Styrofoam? Everything You Need To Know

When you just want to heat something up quickly, you might not think twice about whether or not you can microwave styrofoam. You just stick it up, punch in some numbers, and, most of the time, everything turns out OK.

But can you microwave styrofoam safely? And why does it sometimes melt, turning your food into a hazard waste zone?

While styrofoam is convenient for take-out and as a disposable storage container, it’s not always safe to use in the microwave. There are different types of styrofoam, so you should be careful about what goes in the microwave.

Let’s break down the most common questions people have about styrofoam below; I hope they help you, too!


What’s Dangerous About Putting Styrofoam In The Microwave?

Well, the simple fact is that something like this can happen when you microwave styrofoam:

Scary, right? Imagine if that happened without you noticing! Not only will the styrofoam melt, but you could cause a bigger fire. Microwaving styrofoam can be dangerous.

Even if you don’t see a fire when you microwave styrofoam, it might still be emitting dangerous chemicals into your food:

Simply put, heating styrofoam can cause it to:

  • Melt: This will contaminate your food, and also cause a big mess that you’ll have to deal with.
  • Catch fire: Depending on how your microwave works, styrofoam could catch fire inside of it. If not noticed, this could cause a bigger fire in your home and should be avoided at all costs.
  • Emit toxins: Even if the styrofoam does not melt, it could be emitting toxins. These toxins can cause health problems over time, so you should avoid microwaving styrofoam as much as possible.

It’s not smart to microwave most types of styrofoam. Of course, there are always some exceptions!

What Kinds Of Styrofoam Can I Microwave?

The only type of styrofoam you should ever microwave is styrofoam that is marked to be microwaveable. If you aren’t sure, skip it.

Common items made of styrofoam that are microwaved (that probably should not) include coffee cups, takeout containers, disposable plates, and cup noodles.

At the base level, there are two different types of styrofoam. One is microwaveable, and one is not.

How Can I Tell The Difference Between Different Types Of Styrofoam?

There are many different types and sizes of styrofoam containers.

  • Logos: There might be a logo on the bottom of the styrofoam indicating whether or not it is microwaveable. Usually, this is a picture of a microwave. If there is an X over it, you cannot microwave it. Make sure to check this before microwaving styrofoam.
  • Packaging: The packaging for the styrofoam item should indicate whether or not it can be put in the microwave. If it doesn’t say either way, it’s best to assume that you can not microwave it.
  • Thickness: If there is no indication on the packaging, you can check the thickness of the styrofoam. The thicker it is, the less likely it is to melt or catch fire. This does not mean that toxins are not being emitted while it is heated, however, so keep that in mind.

What’s The Safest Way To Microwave Styrofoam?

The safest way to microwave styrofoam is to NOT microwave styrofoam!

I know, that’s not the answer any of us wanted, but it’s the truth.

It’s hard to know whether or not it’s safe to microwave styrofoam. Even if it isn’t melting, it could be releasing chemicals into your food. It’s better to use a plate that you are sure is microwave safe. There’s no way of knowing, so avoiding it is the safest way to avoid any potentially dangerous situations.

If you really want to use styrofoam, make sure you use styrofoam that claims to be microwave safe and has a higher density.

If you really must microwave it, remember THIS!

Be smart while choosing what to microwave and for how long.

There’s another secret to microwaving styrofoam. The rule goes something like this: You can microwave anything on styrofoam, as long as the food doesn’t get hot enough to melt the styrofoam.

It might be surprising, but it’s not the microwave that melts the styrofoam; it’s the food. If the food is going to go over 175 degrees, it will melt some of the packaging, even if this melting isn’t visible to the eye. The more packaging that is melted, the less safe the food becomes to eat.

Foods that get hot very quickly, have grease on them, or are already slightly warm should not be heated on styrofoam. The microwave will heat them too quickly, and this will cause the styrofoam, in many cases, to melt.

What Are Good Alternatives To Styrofoam For Microwaving?

If you’re wondering what to heat up your leftovers in now, don’t worry. There are many great alternatives. Try one of the following options to use in the microwave to keep your microwave clean and your food safe.

When it comes to microwaving, the bottom line is that you need to be smart about what you heat up and how you heat it up. It’s possible to microwave food safely by taking the correct precautions.

Be A Smart Microwave User

Don't have regrets. Choose wisely when microwaving.

Think twice before throwing your leftovers straight into the microwave in the styrofoam container they came home in. You might be subjecting yourself to a dangerous situation or fire. Even if the styrofoam does not melt, you could be eating dangerous toxins that are emitted during the microwaving process.


  • Check if the styrofoam is microwave safe
  • Microwave for short amounts of time
  • Use another microwave-safe dish instead if possible

Have you learned a lot about microwaving styrofoam?

I hope so. Let us know your tips or questions in the comments below, and make sure to share with your friends so they can avoid this dangerous situation!

Sophia Gardner

I'm Sophia, food blogger, dog lover, homemade cooking and travel passion. I really hope you enjoy my blog, i'll do my best to share great recipes, healthy living tips and just general 'food' thoughts!

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