Safety Tips For Using Glass In The Oven

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When there’s high heat and glass involved, taking precautions is always better since one wrong move can put you at risk of injury. So even if the glass container states that it’s heatproof, don’t put it into the oven without ensuring it can withstand the heat you will subject it to. 

Not all glassware is oven-safe, so check for the oven-safe symbol or label on your dish before putting it in the oven. You can also read through the user manual. When heating leftovers, let the glass container come to room temperature before putting it in the oven.

So is all glassware oven-safe, or will some shatter or explode in the oven? Is there any way to tell if it’s oven-safe? How much heat can you subject it to before it finally breaks? What are the benefits of using glass over other materials? Let’s take a look. 

Is All Glassware Oven-Safe?

A method of cleaning in a microwave oven with water and lemon

All glassware is definitely not oven-safe. Some glass products, like casserole dishes and Pyrex bowls, might be heat-resistant to a certain degree but you should assume glass isn’t oven safe unless it’s stamped or you know it’s origin and that it’s OK.

But the safest option in the oven is tempered glass, designed to be up to four times stronger than regular glass. While options like this simple bakeware set (example on Amazon) advertise themselves as for “bakeware,” it’s also good to understand how to figure out if glass is oven safe if you don’t have the product page handy.

Even though tempered glass is more robust than ordinary glass, you shouldn’t assume the piece of glass you have is safe to put in the oven. Always research and check out all pieces of glassware before subjecting them to the oven’s high heat. 

How to Check if Your Glassware is Oven-Safe

It’s pretty easy to tell if you have oven-safe glass at home with a few simple tricks. So if you want to check if your plates, cups, drinking glass, or dishes are oven-safe, here’s how you can do that:

Look for the Oven-Safe Symbol

The easiest way to check if your glassware is oven-safe is to look for an oven-safe symbol. The symbol involves a bowl inside an oven and heat waves on top of the bowl directed upwards. 

Symbols are typically engraved on the product’s underside or might be present on a label pasted on the dish.

However, you might not find this symbol on all oven-safe glassware since it’s not recognized universally. For instance, if you got your glassware from abroad, you might see a different symbol. In addition, you might see variations in the symbol or text saying that the product is oven-safe.

So before doing anything else, make sure you look out for this.

Check the Manual or User Guide

If you recently bought the glassware and have the user guide or manual stashed somewhere, you’re in luck!

You can go through it to see if you can use the glassware in the oven. Some manuals even mention how you can heat the glassware.

Simply Google it

If you have an older glassware product and don’t have the user manual lying around somewhere, you can turn to Google. And if you know the product’s brand, things get even easier—you can directly check the company’s website. 

Of course, you might have to spend some time trying to find the right product on the website. But if you’re lucky, you’ll come across all the details of the product you need. 

Will Glass Explode in the Oven?

Even if the glass is tempered or labeled oven-safe, you can’t be 100% sure that it won’t explode in the oven.

For instance, if your glassware has a lot of scratches or cracks or is right on the verge of breaking, there’s a high chance it’ll shatter once exposed to high temperatures. 

Plus, dishes labeled oven-safe still have a maximum temperature limit that they can handle. And it’s better if you search for this in addition to the oven-safe label so you can be sure the recipe you want to make doesn’t require a temperature greater than what your glassware can handle.   

You should also remember that even if the glass is labeled oven-safe, it might not be able to handle sudden temperature changes, and ultimately, the glass might break. 

For example, if you want to reheat leftovers in a glass dish, you shouldn’t take out the cold dish and directly chuck it in a preheated oven. Instead, take the container out of the fridge well before it’s time to eat and let it come down to room temperature before putting it in the oven.  

What is the Highest Temperature Glass Can Withstand?

Young woman using microwave oven on table

The answer to this question depends on the glass you use. This is why it’s always essential to go through the manufacturer’s guidelines and understand what your glassware can handle before putting it in the oven.

If the glass is thin and of poor quality, it might break if it’s subjected to heat up to 150-200 degrees Centigrade.

However, oven-ready glassware is comparatively thicker and can better withstand greater temperatures.

What Temperature Will Cause the Glass to Break?

Typically, glass jars and bottles aren’t affected by warm, refrigeration, or ambient temperatures. However, they’ll break or shatter if you subject them to excessive thermal variations or high heat of over 300 degrees Fahrenheit.

Glass is notorious as a poor conductor of heat, and quick, sudden temperature changes can result in stress fractures in the glass, causing the glass to crack. When subjected to heat, the thin glass starts to crack and usually breaks around 302-392 degrees Fahrenheit.

And suppose you place the glass container on an extremely hot heat source. In that case, it can eventually lose its shape and even go from a permanent solid to a plastic state.

Glass might also break if you subject it to below-freezing temperatures. The contents might freeze and cause the glass to crack when they expand.

Also, remember that it’s better not to heat glass jars in the oven or microwave. This is because most glass jars are made of ordinary glass, which can crack or even explode in the microwave. 

However, glass containers labeled microwave-safe and made using heat-resistant materials are safe to put in the microwave. Just make sure to remove the lid of the container before putting it in the microwave, 

What are the Benefits of Cooking with Glass vs. Other Materials?

If there’s a chance of the glass breaking, why not opt for other materials like Pyrex or ceramic? Why stick to glass?

Well, the truth is that even though glass can break in the oven if not used carefully, it offers several benefits. Let’s go through them one by one.


Materials that feature non-stick surfaces often release toxins when subjected to high temperatures. However, that’s not the case with glassware—it’s non-toxic. So if you want to eliminate chemicals and toxins from your life as much as possible, switch to cooking with glass.

Better at Retaining Heat

Compared to other materials, it takes glass a little longer to heat up, which many find frustrating. But at the same time, glass can retain heat longer than most other bakeware, making it a better serving dish.

It can keep the food warm for longer so that you and your guests enjoy a nice meal. 

Ability to See the Contents

Another benefit of cooking with glass, especially when baking, is that you can see the food contents inside the container as they cook.

In comparison, if you opt for any other kind of bakeware, you’ll only be able to see the top surface, making it tricky to determine how much longer you need to cook your food.

Ease of Cleaning

This doesn’t directly apply to cooking, but cleaning up is one of the biggest hassles you have to deal with once you’re done making your favorite dish, and having a dish that’s easy to clean makes things a little easier.

This is where glass is a good option. It’s non-porous and comparatively easy to clean.


In addition to cooking food, you can use the same glass container to store and reheat leftovers. However, that’s not the case with other cookware; you must put the leftovers in a different container if you want to store them.

In the case of glass, you must let the food cool down before putting the container in the fridge or freezer.

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