Is Pyrex Microwave Safe? Know Everything Here

by Sid Wilson | Published On

Each product we feature has been independently selected and reviewed by our editorial team, is reader-supported. If you make a purchase using the links included, we may earn commission, at no extra cost to you.

Pyrex is a trademarked company that makes glassware, which is heat resistant and has resistance to chemicals and electricity as well. It’s been used to make chemical apparatus, ovenware, thermometers, etc.

The chemical composition of Pyrex contains borosilicate and changes its composition when heat is applied to it but only one-third of what standard glass does.

Due to this, it does break as the common glass would have, it’s resistant to chemicals and electricity, as it’s a very good insulator.

The typical composition of Pyrex is-

SiO²= 80.6 %

B²0³ = 13.0 %

Na2O= 4.0 %

Al203= 2.3%

Some of the chemical properties of Pyrex have high resistance to water, acids, halogens, etc. Only Strong acids can corrode the material.

Due To low and high levels of temperature flexibility, it’s used in cookware, low level of expansion & contraction due to temperature change makes it a favorite among other glasses.

Pyrex Microwave Safe?

What's So Special About Pyrex Glass?



It’s a glass composed of pure sand, with soda, aluminum, and more, this mixture when melted in an oven, at a very high temperature, turns into this clear material, which is quiet It’s then refined and made into this versatile material called PYREX.

The Pyrex company makes products of glass, which are specially designed for cookware and used in freezers.

It’s made up for your perfect culinary experience, from being used as a pot or by storing hot food in it or used in microwaves for reheating your leftovers.

Is It Safe To Microwave Pyrex?

Pyrex is a company that claims to make quality kitchenware products, with an unbeatable track record in terms of quality products.

The company says that its products are known for withstanding heat at very extreme temperatures due to their highly resistant glass type.

Pyrex is safe to use in a microwave but there are a few things to keep in mind before you cook in Pyrex cookware in a highly heated microwave.

Never use a cold Pyrex, in a hot microwave, always pour some hot water ) liquid into a cold Pyrex measuring cup Or you can put the hot cup onto a cold surface,

It’s a reminder to never use a cold Pyrex in a hot preheated microwave or vice versa,

Pyrex is a very good heat conductor but it can mess up when its thermodynamics aren’t kept in mind, as the transfer of heat will lead the Pyrex to break into little pieces or it can shatter or have cracks.

The company states that it’s microwave safe but asks its users to never give the cookware any shock of extreme temperatures into the glass by putting it in hot water or anything extremely hot or cold, which results in the breakage of the dishware.

When glass products are introduced to an extreme amount of heat, they tend to go into thermal shock as there is a massive Shift of temperature, in a thermal shock the material of glass expands differently, which causes thacks and shattering of the hardened glass.

When a Pyrex glass is exposed to rapid high-temperature shifts, it just can’t handle extreme temperatures as this uneven expansion might lead to the breaking or bursting of the cookware.

But if you use a Pyrex glass in a microwave you need not take tension About the shattering or the breaking of it, but if you replace it with a freezer and you keep it in a heated microwave may cause a

But the company takes pride in Its quality and durability were meant to stand the test of quality and the trust of the loyal customers. You need not worry about breakage when you are using a Pyrex product.

How Long Can You Safely Microwave Pyrex?

As it’s preferred to use glass and ceramics whenever we think of cooking at extreme temperatures,  these materials are known for their durability and performance as compared to plastic or any options available.

Whenever we use Pyrex glass we get proper guidelines on the package, according to the sizes and shapes, the quality depends on that.

For a while of 1000 hours max, Pyrex cookware has been tested and then introduced into the market, the testing makes it clear that we can use it.

Pyrex cookware may last up to a very long time duration, and it won’t harm us. The test is conducted on a very high level, much above the normal hours at which we normally do, so it’s safe for you to use Pyrex cookware.

Is It Safe To Use Cold Pyrex?

As the glass can shatter due to sudden temperature changes, one should not use a cold Pyrex, enclosed by a hot microwave, just acts as an explosive and can’t bear the thermogenic shock.

It’s better to either use it in a refrigerator or a microwave, the problem arises when the transfer from hot to cold or cold to hot happens too quickly, then it may not be able to cope with the fluctuations in the temperature.

It’s not safe to use a cold Pyrex. Keep things in mind when it’s used very quickly right after it is inside the hot microwave.

Is It Possible For Cold Pyrex To Explode In The Microwave?

If you keep your Pyrex glassware in an already hot microwave, then uneven expansion & contraction of the glass will make the glass explode inside the microwave.

Always wash your Pyrex glassware with some hot water and then keep it inside the microwave, by this process you’ll not break the Pyrex glassware and it won’t cause you that much harm.

Tips For Microwaving Cold Pyrex?

The following tips should be considered while microwaving cold Pyrex-

  • You can’t use Pyrex cookware on the gas stove or burners, they are meant to be used in the microwave Only.
  • Do not use oil or heat meats or cook your favorite bag of popcorn In a PYREX container, it will shatter into tiny bits and pieces.
  • The container should be broken From anywhere before going to the Microwave.
  • The microwave comes in all different power and different types of voltages, beware of that before putting in your cold Pyrex.
  • Never touch the microwave without your gloves unless you want to burn your fingers.
  • If you are cooking something which requires long hours of cooking
  • Just don’t use Pyrex and use different microwave-friendly cookware.
  • As we know, thermogenic health just shocks the Pyrex container, and it just breaks when we keep it straight onto a cold surface.
  • If you are cooking something when is dry, remember to add a little bit of water to the bottom of the Pyrex cookware.
  • Do not add cold or hot water Inside a container, it will shatter the Pyrex container.
  • Always wash the cold container with some hot water, so that it doesn’t break.

Can Pyrex Go from Freezer To The Microwave?

It’s not a wise idea to do so, Pyrex is for sure made up of sturdy material, but that doesn’t mean it won’t break Or shatter into pieces.

You should never put Pyrex straight from the freezer into a microwave, due to extreme temperature shock, they could explode.

In very little time, molecules move at a very high Speed, resulting in

Breakage of the glass or even bursting into The microwave. Placing one ice-cold Pyrex will result in an Explosion of the cookware, which no one would like to do.

Can You Microwave Pyrex Lids?

Yes, we can microwave Pyrex lids. Pyrex Lids are of two main types- One is a Glass one and the other one is the plastic one.

The glass lid is made from the same material used in the containers, but as the glass containers change due to extreme temperature shock, these lids also change and can break down. They are ideal for both an oven and a microwave.

The Plastic Lids, on the other hand, are BPA – free, so they are safe to be used in microwaves but sadly they aren’t useful for ovens as they are not heat resistant, which will make them melt and that’s why they aren’t good for ovens.

What Temperatures Are Safe For Pyrex?

The material from which Pyrex is made up of is boric oxide and silica, so the durability of Pyrex is very incredible.

It can withstand up to 1510 ° F and that’s a very high temperature to make up to melt down, your favorite Pyrex glassware, it’s safe to say that this cookware is meant to withstand all the heat.

When we talk about extreme temperatures, we should also talk about extremely low temperatures too, Pyrex glassware can withstand a temperature, as low as – 104°f, up to – 572°f

So don’t worry, this got you covered and you need not take any tension regarding your cooking experience & safety.

Can Pyrex Go In The Oven?

The makers designed it in a way that they say could be used in the oven, you can put your Pyrex glassware into the oven, but you need to take a few precautions when cooking inside the oven.

Don’t forget to preheat the oven, beforehand, don’t put straight into the oven anything with extreme temperatures.

Never put the Pyrex container Below is a broiler, if you are up for cooking something which contains fats, juices, or water.

Put some water underneath the Pyrex container, to avoid it from breaking.

Whenever You take out hot Pyrex glassware, it’s always advisable to never put it directly on a cold surface or a wet or metallic surface, as it will make the material break down.

You can place it on an oven tray, a wooden table, or a hot pad So it absorbs all the heat and doesn’t shatter.


Pyrex is very good dishware and it’s very helpful in the kitchen to use Pyrex. There are a few situations that you should always keep in mind when you’re dealing with Pyrex.

As discussed above, the sudden temperature change is what makes Pyrex the villain, here So altogether you must keep these things in your mind while cooking with Pyrex.

As long as you keep these precautions in mind, you will go on a long journey with your Pyrex Glassware and it’s going to work wonders for you.

Rate this post
Sid Wilson

Being a father, a golf lover, and an engineer by profession are the things that define Sid Wilson. He spends most of his time in his garage building and experimenting with stuff. Unscrewing things and then screwing them up is his favorite hobby. Doing these things in his garage has made him what, he is today.

Leave a Reply

Your email address will not be published. Required fields are marked *