Is Pyrex Microwave Safe? What You Need to Know

Quick answer: Is Pyrex microwave safe? Yes, as long as the dish is clean, undamaged, and free of metal trim. Avoid sudden temperature changes, such as going straight from the freezer to the microwave, remove any sealed lid so steam can escape, and heat food in short bursts.

When investing in Pyrex containers, we want to be sure they can be safely frozen, microwaved, and baked in the oven. This is what the Pyrex manufacturer claims.

But what is the reality? Some users report different issues like cracks, explosions, or others. Let's discover the advantages and disadvantages of using Pyrex in the microwave.

What is Pyrex? Pyrex vs. PYREX

You might be wondering what Pyrex is. Pyrex is an American brand of manufactured glass known since 1915. With a long history, Pyrex has earned respect for its durable cookware and bakeware.

Until the 1950s, Pyrex used borosilicate glass for manufacturing. Nowadays, the PYREX brand still makes borosilicate PYREX products, while American Pyrex manufactures tempered soda-lime glass products.

Here is what you will discover in the world's market:

• French PYREX is made from low-thermal-expansion borosilicate glass,
• American Pyrex is made of tempered glass.

Is Pyrex microwave safe?

Glass is microwave-safe, and Pyrex glass is considered microwaveable, so the short answer is yes. In addition, it is plastic-free (it doesn't contain BPA), stain-resistant, non-porous, does not absorb any food flavors or odors, and is durable.

Although Pyrex is microwavable, there are certain conditions to bear in mind while using it.

Can Pyrex go in the microwave?

Can you put Pyrex in the microwave? Yes, you can, but there is something more important to know.

Before buying it, make sure to examine the Pyrex logo. PYREX®, spelled with capital letters, is the safest borosilicate. It indicates either a vintage Corning Glass Works product or a new French product.

American Pyrex (all lowercase) is made of tempered soda-lime glass, the standard glass type used for household products.

If you can't find a logo, pay attention to where the Pyrex product is made. If it is made in France, it is borosilicate glass. Pyrex glassware, made in the USA or, lately, China, is made of high-quality tempered glass.

PYREX® is safer than American Pyrex since borosilicate is more resistant to thermal shock. This matters when you move a glass product from one place to another.

For example, take a Pyrex dish out of the freezer and immediately put it in the microwave. It may result in an exploding Pyrex dish.

Please watch this Consumer Reports video about the high resistance of French PYREX compared to American pyrex®.

French borosilicate glass has an exceptional thermal resistance of up to 572°F (300°C). Soda-lime Pyrex has a lower maximum temperature.

The American Pyrex glass melting point is 1510°F (821°C), while the French PYREX melting temperature is between 2552 and 2912°F (1400 and 1600°C).

So, carefully read all the details when purchasing and using Pyrex glass containers.

Can you microwave Pyrex lids?

Most Pyrex cups, jugs, bowls, and dishes come with glass or plastic lids. If you can microwave Pyrex glassware (as long as you avoid abrupt temperature changes), you'll probably want to know whether you can microwave Pyrex lids.

The official Pyrex website says Pyrex glass lids made from the same material as the container are microwave-safe.

If a plastic lid accompanies the Pyrex, it is another story. Even if the lid is BPA-free, it isn't always as heat-resistant as its glass counterpart.

So read the product description or manual carefully. For example, don't worry about microwaving Pyrex lids if it is written, "Non-toxic lid: BPA-free plastic lid is freezer, microwave, and top-rack dishwasher safe."

Tips for microwaving Pyrex

While Pyrex is microwavable, there are a few tips to consider:

• Check Pyrex glassware for cracks before microwaving.
• Don't pour hot liquids into cold Pyrex measuring cups.
• Never put a hot Pyrex container on a very cold surface. 
• Avoid instant temperature changes like 100-120 degrees Celsius: preheat your Pyrex dish before placing it somewhere with the extreme temperature difference.
• Never microwave an empty Pyrex cup for any reason.
• Handle hot glass from the microwave with oven mitts.

American Pyrex can't go from the freezer to the microwave. Glass exposed to extreme temperature changes can crack, burst, or even explode into a thousand tiny pieces. 

But according to the official website, PYREX.fr,

You can use a borosilicate glass dish and take it from the freezer (or refrigerator) to the oven or the microwave with no problem.

It means French PYREX withstands thermal shock from -4°F (-20°C) in the freezer to the oven's 464°F (240°C). It is also so durable that, if you accidentally break it, it will break into several large pieces for added safety.

But are there any tips or safety precautions for microwaving a cold Pyrex dish?

• Let the Pyrex cup or bowl reach room temperature after coming from the refrigerator or freezer before bringing it to the microwave.
• Preferably, microwave Pyrex in short intervals to decrease the chances of thermal expansion.

How can you tell if Pyrex is microwave-safe?

First and foremost, check your Pyrex cookware for the logo. PYREX® items with capital letters in the logo are safer than their American cousin, tempered soda-lime pyrex®.

If in doubt, read about the material the Pyrex is made of: borosilicate glass or soda-lime glass. Then, choose one made of borosilicate glass.

Always read the manufacturer's instructions or manuals that come with your purchase, or look for them online.

The last thing to check if Pyrex glass is microwavable is to perform a microwave test. Pour a glass of water into your dish and microwave it on high for a minute.

If the Pyrex is hot to the touch (be careful), avoid microwaving it. If the dish is cold, but the water is hot, you can use it in the microwave.

Attention: Use dry oven mitts to handle the Pyrex glass dish.

How long can you microwave Pyrex?

Compared to Tupperware, ceramic and glass are the best options for microwaving. These are heat-resistant and microwave-safe.

Before being introduced to the market, Pyrex kitchenware was tested for up to 1000 hours. So you can use it freely and safely in everyday life, following the manufacturer's guidelines.

What Pyrex dish is best for the microwave?

The best dish depends on your taste and cooking methods. For example, some prefer bowls, while others use dishes and cups.  

You may prefer to stock up your kitchen with different types of Pyrex glassware for other purposes. Read more about baking essentials in the kitchen.

To cook optimally and safely, opt for Pyrex® borosilicate glass dishes, for example,

• Pyrex glass measuring jug
• Pyrex glass baking dish
• Pyrex oven dish

If you live in the United States, you will find it hard to find French Pyrex glassware. So you may want to order cups, bowls, storage containers, and other dishes from Amazon.fr.

The variety of Pyrex products is outstanding for making homemade lasagna, quiche, and Brioche French Toast Casserole; you name it.

Is vintage Pyrex microwave safe?

Most vintage Pyrex is glass, so it will not spark like metal, but age changes the picture.

Older American pieces were made from borosilicate glass and handle heat well, while later ones switched to soda-lime glass, which is more sensitive to sudden temperature swings.

The bigger concern with collectible pieces is the decorative paint on the outside, since some older patterns used lead-based or metallic paints that can heat unevenly or leach.

For everyday reheating, use clear, unpainted vintage Pyrex that has no chips or cracks, and warm food gently in short bursts.

Keep prized painted or patterned pieces for serving and storage rather than the microwave, and never subject an old dish to a sudden change from cold to hot. If you cannot confirm the material or condition, treat the piece as display-only to be safe.

Is Pyrex safe in the oven, freezer, and dishwasher?

Pyrex glassware is designed to move between the freezer, refrigerator, microwave, oven, and dishwasher, as long as you avoid sudden temperature changes and never expose it to direct heat such as a stovetop or broiler.

In the oven, use the dish without a plastic lid and place it on a room-temperature rack rather than into a screaming-hot one. Lids and plastic covers are usually freezer- and microwave-safe but not oven-safe, so remove them before baking.

The one Pyrex you should not put in the oven is any piece made of soda-lime glass or any dish with a chip or crack, since both raise the risk of thermal shock.

Let a hot dish cool before washing, and it is dishwasher-safe on a normal cycle. When moving from freezer to oven or microwave, let the dish sit at room temperature first so the glass warms gradually.

Conclusion

Can Pyrex be microwaved? Pyrex is microwave-safe, but please avoid the drastic temperature shifts described above.

Always follow the manufacturer's usage instructions for Pyrex glass products and microwaves, and follow safety guidelines. For example, avoid placing Pyrex on a hot stove, and don't use it in a toaster oven, under the broiler, or on a grill.

FAQ

Is Pyrex glass?
Pyrex (trademark) is a branded type of glass with high heat, chemical, and electrical resistance.

Can you microwave Pyrex glass?
Pyrex glass is microwavable, with one exception: avoid direct heat and sudden temperature changes, such as a swing of about 100-120°C (212-248°F).

How much heat can Pyrex withstand?
French PYREX, made of borosilicate glass, has an exceptional thermal resistance of up to 572°F (300°C). Tempered soda-lime Pyrex withstands 425°F (218°C).

Does Pyrex explode?
Pyrex can explode if exposed to rapid temperature changes, known as thermal shock. For example, it can happen when transferring Pyrex from the freezer to the microwave.

Does Pyrex break?
With a drastic temperature change or by accident, Pyrex can break. While tempered soda-lime Pyrex breaks into multiple small pieces, borosilicate PYREX breaks into larger pieces.

Can you microwave Pyrex bowls?
You can microwave Pyrex bowls as well as Pyrex cups, food storage containers, and other dishes. They are heat-resistant, BPA-free, hygienic, and highly durable.

Can you microwave vintage Pyrex?
Vintage Pyrex was most likely made of borosilicate glass, which is more resistant to thermal shock than newer tempered soda-lime glass. Furthermore, you can safely microwave vintage Pyrex.

Is Pyrex glass oven-safe?
According to the Pyrex manufacturer, Pyrex glass is oven-safe for both conventional and convection ovens. It is perfect for preparing, storing, cooking, baking, warming, or reheating food.

Which Pyrex cannot go in the oven?
Any Pyrex made of soda-lime glass, any piece with a chip or crack, and all plastic lids should stay out of the oven. Use only oven-safe borosilicate or tempered dishes, and remove lids before baking.

Is there a Pyrex microwave-safe symbol?
Look on the base for a small microwave icon (wavy lines) or the words "microwave safe." If there is no symbol, check the brand logo and material, or run a quick microwave test before regular use.