Is Pyrex Microwave Safe? (What you Need to Know)

With more and more research coming in every day about the health hazards of using cardboard or plastic containers it was about time that people would switch over to glassware for cooking.

And of course, the brand that people would flock to for a microwavable container is Pyrex. The most popular brand of glassware available on the market, and one that’s been around for approximately 100 years is Pyrex.

Originally developed as a solution for food storage back when plastic Tupperware wasn’t as popular, it quickly evolved as a solution for stovetop cooking as well.

Now in the age of microwave cooking, Pyrex has shown just how suitable their products are to work as a microwave-safe line.

But the question still remains, are all Pyrex products safe to be used in the microwave?

You might be assuming since it’s glass there could be a risk of keeping it in the microwave and “KABOOM” your Pyrex container spontaneously combusts.

Luckily, you found this article so that will not be the case if you learn and follow the proper guidelines for safely using Pyrex glassware with your microwave.

Read on ahead as I help you understand how to work with Pyrex and you’ll confidently and safely be microwaving all your favorite meals in it in no time.

Can you microwave Pyrex?

The short answer is Yes, of course.

Pyrex is safe to be used in the microwave. In fact, I’ve been using it for years now.

If you follow the right temperature settings, heating methods, and care guidelines then you can rest easy knowing that Pyrex glassware won’t give up on you any time soon.

In fact, I might even have some Pyrex bowls in my home that could be old enough to be called heirlooms.

Is it safe to microwave Pyrex?

I understand where this question is coming from. Not long ago there was an urban legend of Pyrex dishes cracking or even exploding when placed in the microwave.

But since I had been using them for ages with no signs of this ever happening I set out to find out where this rumor came from.

A quick Google search showed me that there were some instances where a Pyrex dish did happen to crack or collapse when microwaved. But read the fine print here folks, what were the conditions of the Pyrex dish itself like before it shattered?

Was it placed directly from a freezer to a microwave? Or placed in the freezer while the food inside was still hot?

To answer your question, yes microwaving Pyrex is safe, but like all glass, it is not resistant to thermal shock. Drastic temperature changes can cause it to shatter or crack.

Is it safe to microwave food in Pyrex?

Yes, microwaving food in Pyrex dishes is definitely better and recommended than using paper or plastic dishes.

According to the Pyrex manufacturers, all of their products are BPA-free. The same sadly can’t be said for most plastic Tupperware, hence making Pyrex safe to be used for heating in the microwave or oven without the hazard of dangerous chemicals leaking into your food.

Besides this, the FDA has determined that the material used to make Pyrex (tempered glass) is Generally Regarded As Safe (GRAS). GRAS designation indicates that experts have determined that the products have no side effects on human health and are safe to use.

Although microwaving food in glass Pyrex dishes is generally perceived as being safe, it’s still important to be careful of how you handle your foods to keep the glass dishes safe.

How long can you microwave Pyrex?

Pyrex tests its cookware for up to 1000 hours, as being safe to be used under heat, before being introduced into the market.

This means you can safely use Pyrex glassware for quite a long time at home because the testing far exceeds regular usage,

However, make sure when you use your Pyrex cookware, the cooking time doesn’t make the heating temperature exceed 450 degrees F, and you thoroughly check your dish for any compromised quality.

Follow the guidelines of the manufacturer to avoid any unexpected turn of events.

Safety Tips for Using Pyrex Glassware:

Here are some handy tips to keep in mind when handling Pyrex dishes:

  • Be mindful of extreme temperature changes: While Pyrex is safe to be used easily in the microwave, it is still very susceptible to drastic temperature changes.

This means you cannot place a dish of Pyrex directly from the freezer into the microwave or oven for heating. Or keep a Pyrex dish with hot food in the freezer. Always bring food contained in Pyrex cookware to room temperature before exposing it to extreme heat or cold.

  • Cool liquids to room temperature before pouring directly into Pyrex glass: Again be wary of exposing your Pyrex dishes to sudden temperature changes. If using Pyrex for storing foods like soup, let it come to room temperature first before your pour it into the glassware otherwise you run the risk of cracking your glass.
  • Avoid contact of Pyrex glass on open flame: While you may think that since Pyrex dishes can be safely exposed to heat in microwaves and ovens, they can be used as cookware on stovetops as well.

This may not hold true for all kinds of Pyrex dishes, therefore always read the label and instructions to determine if your particular kind of Pyrex is suitable for stovetop cooking.

  • Never microwave an empty Pyrex cup. I know this may seem like an obvious one, but just like you wouldn’t microwave empty paper plates or cardboard boxes never microwave a Pyrex cup without anything inside it.
  • Direct exposure to microwave heat without having food inside to absorb it can crack your glass.
  • Don’t place hot Pyrex on a cold surface: Another cardinal rule for using glass. If you place hot Pyrex on a cold surface like a kitchen counter, it may crack due to thermal shock that occurs when two different temperatures meet. Always keep a trivet or a cooling rack on the counter before placing your hot Pyrex dish on it.
  • Add a little liquid when heating in Pyrex glassware. A good rule of thumb is to always add a little bit of liquid, even when heating a dry dish. The addition of liquid will create steam which will warm up the food nicely as well as protect the bottom of the Pyrex dish from getting too hot.
  • Use oven mitts to handle hot cookware. This I think is a no-brainer. Whether you are using Pyrex dishes or any other kind of cookware, make sure that you always use oven mitts to handle hot cookware.
  • Check for cracks before putting your Pyrex in the microwave. Sometimes with repeated use, washing, and incorrect handling, Pyrex dishes can start to develop cracks, especially on the bottoms. Before keeping it in an oven to heat food always check for cracks to avoid any disasters.
  • Check appropriate temperature levels: Pyrex manufacturers recommend that your dish shouldn’t be heated at more than 450 degrees F, anything more than this will compromise the quality of the glass and may cause it to break.


While Pyrex can be microwave safe, you need to be safe about it too.

Follow the manufacturer’s guidelines to avoid any potential cooking disasters.

If your Pyrex product doesn’t come with its safety guidelines printed on the product, it can be easily located online.

The main rule to remember here is to avoid sudden exposure to extreme temperature changes and you should be good to go.


What is Pyrex?

Pyrex is a type of borosilicate glass that is heat-resistant and durable, commonly used to make labware and other kitchen products such as ovenware, dishes, bakeware, and measuring cups.

Is cold food safe in a hot Pyrex dish?

Yes, cold food can be placed into a preheated hot Pyrex dish without fear of it shattering or breaking since this type of glass can withstand extreme temperature changes due to its borosilicate composition.

What types of lids are available for Pyrex glass bowls?

There are plastic lids available for all sizes of pyrex glass bowls which are both airtight and leakproof, making them perfect for storing leftovers in the refrigerator or freezer. Additionally, there are also microwave-safe pyrex lids made from tempered glass, which can also be used when heating food up in the microwave oven.

Can I use a plastic lid on a Pyrex Glass Bowl?

Yes, you can use a plastic lid with a Pyrex glass bowl. However, it is not recommended to do this as the plastic may melt or warp when exposed to heat.

How should I safely microwave Pyrex?

It is safe to microwave Pyrex as long as it has been preheated before being placed in the microwave and cooled slowly after microwaving. Avoid sudden changes in temperature, such as putting cold items in hot dishes or vice versa, as this could cause thermal shock, which would damage the Pyrex dish.

Is it safe to put cold Pyrex dishes into an oven?

Yes, it is generally safe to put cold Pyrex dishes into an oven provided that the temperature of the oven does not exceed 450 degrees Fahrenheit for glassware designed by the original manufacturer, which is usually indicated on their packaging or product labels. It’s best practice to allow any dish made by another brand, such as vintage pyrex dishes or other brands of glassware to cool before placing them in an oven.

What are some specific examples of products that are labeled oven-safe from the Pyrex brand?

The Pyrex brand offers many types of bakeware, storage containers, and dinnerware products that are labeled as “oven-safe” and “microwave-safe.” Examples include ceramic ramekins, rectangle cake pans, and round casserole dishes; 3 piece storage sets; 1 quart mixing bowls; dinner plates; mugs; bowls with lids and more. They also offer cookers specifically designed for use in a slow cooker/crock pot or a toaster oven.

Is vintage Pyrex safe for microwaves?
Vintage Pyrex made before 1968 should not be used in a microwave because it does not have the same properties as newer versions of Pyrex. Newer models are made from tempered soda-lime glass and can safely be used in microwaves.

Are Pyrex lids microwave safe?
Generally speaking, yes – pyrex lids are BPA-free and can be considered microwave safe.

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