Can You Microwave Glass? (Everything You Need To Know)

The other day, I came home with a serious question: Can you microwave glass?

It might sound like a silly question, but I was about to microwave something in a glass bowl at work when my coworker started telling me about how glass can apparently explode in the microwave.

Scary, right?

I found out that there are different types of glass, and depending on the type of glass and how it was made, it could in fact explode in the microwave! Let’s get into this topic & discover if your glass can be safely put in the microwave or not.


What Is Glass?

The first thing you should know when finding out the answer to your question is what glass really is.

Glass is made when sand is heated to a very high degree until it turns into liquid. As it cools, the structure changes and a crystalline structure appears.

Here’s a quick video explaining how glass is made and what it is:

Got it? Perfect! Now that we know what glass is, we can get a better idea of whether or not it is safe to microwave glass.

How Do I Know If Glass Is Microwave Safe?

The only sure-fire way to know if a glass is microwave safe or not is to check if it has a logo on the bottom indicating that the glass is microwave safe.

If there is a logo of a microwave, it is safe to put in the microwave.

This logo is only put on items that have been rigorously tested to show that they can withstand the pressure that a microwave puts on the glass.

The good thing to know about most glass bowls and baking cookware is that it is made of tempered glass. This means that if the glass breaks, it should break into larger chunks rather than shattering into tiny pieces. This makes it safer.

What If There Is No Label On My Glass Cookware?


If there is no logo on the bottom of your glass, chances are high that it is still microwave safe.

Most glasses will not have any problem if they are put in the microwave.

Here is an easy way to test if the glass vessel you have can be put in the microwave.

Take the glass object, add some water to it, and put it in the microwave for one to two minutes. Once the time is up, take it out of the microwave carefully. The water should be hotter than the glass.

If the glass is very hot, it is not microwave safe as it is heating up too quickly. If the glass is still cool or warm to the touch, it is safe to use in the microwave. This is a very simple way to find out if any glass item that is not marked as microwave safe can be used in the microwave or not.

What Else Should I Avoid?

Always check the bottom of a glass to make sure there is not a logo saying that it is not safe to put in the microwave. If this is present, you should never put it in the microwave.

Additionally, you should never put a glass with any cracks or breaks in it in the microwave. These cracks can weaken the glass and lead to a higher risk of the glass breaking when heated. The areas with cracks will heat faster than the rest of the glass, leading to a dangerous situation.

Also, you should always avoid putting glass with any type of metal trim or inlay on it in the microwave. Metal can and will catch fire in the microwave very easily:

So, let’s sum things up. When deciding if you can microwave glass or not, avoid the following:

  • Very thin glass
  • Glass rimmed with metal or lead
  • Glass with any breaks in it

If you avoid these things, you should have no problem safely microwaving glass

Why Is Some Glass Not Microwave Safe?

At this point, you are probably wondering why some glass is microwave safe and some is not. Isn’t it all glass?

Simply put, some glass has more air bubbles in it than other glass. These bubbles could expand during heating, and if they expand too much, the glass shatters.

Additionally, glass might have been dyed to change its color. In some cases, the dyes used are not food safe. If they are microwaved, the dyes can leak out of the glass and into the food. You should always check colored glass for a microwave safe label before using it in the microwave.

How Can I Safely Use Glass In The Microwave?

It’s always good to learn safe practices when you’re planning to microwave something.

The most important thing to remember about microwaving in glass is that you should avoid rapid temperature changes.

If you head up some soup in the microwave to a very high degree and then add a bunch of ice cubes to the glass bowl, it could shatter. Glass is prone to breaking more easily whenever it goes through fast temperature changes.

On a similar note, you should never microwave a cold or frozen glass or bowl. First, let it come to room temperature if you need to put it in the microwave.

Safely Microwave Today!

Can you microwave glass? Yes! Most glass is microwave safe. As long as you are smart about what you put in the microwave, you should never have a problem with microwaving something in a glass bowl or on a glass plate.

The key to heating things up safely in the microwave is always to be aware of what is happening in the microwave. Never heat things for too long, and never put things that you heat up immediately into a very cold environment.

Do you have any other tips for using glass in the microwave? Let me know below, and make sure to share this with any curious friends!

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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