Is Pyrex Microwave Safe? A Thorough Safety Guide

If you are on the lookout for cookware that can offer both dependability and versatility and seamlessly transitions from the fridge to the microwave, the Pyrex dilemma might have crossed your mind. Can you trust Pyrex in the microwave? 

Cooking and reheating meals with Pyrex in a microwave can be convenient, but it’s essential to navigate this kitchen terrain with caution to prevent any accidents.

Let’s delve into the world of Pyrex, starting from its origins and exploring its different types, ensuring you’re well-equipped to make disaster-free culinary decisions in the kitchen.

I. What is Pyrex? 

Pyrex has been an iconic American glass brand since 1915, known for its exceptional quality and reliability.

Crafted through an intricate high-temperature fusion process of silica and boric oxide, Pyrex emerges as a marvel in kitchen glassware. The unique amalgamation grants the glass remarkable strength, rendering it highly resistant to the perils of breakage and shattering.

However, there are different types of Pyrex glassware.

“PYREX” (the brand) continues to craft borosilicate PYREX products, while “American Pyrex” produces tempered soda lime glass items.

For example, French PYREX is made with low-thermal-expansion borosilicate glass, while American Pyrex utilizes tempered glass.

II. Is Pyrex microwave safe? 

In general, Pyrex is considered microwave-safe since it has an extremely high melting point.

The melting point of Pyrex is a staggering 821°C (1510 °F), and it’s simply impossible to reach such temperatures inside your home kitchen microwave. This makes Pyrex glass an ideal material to use in the microwave.

Although the melting point of American-made Pyrex glass is 1510°F (821°C), its French counterpart has an even higher temperature range, spanning between 2552 and 2912°F (1400 and 1600°C).

Moreover, it is free of BPA and features a stain-resistant and non-porous surface. So, it won’t absorb any food aromas or flavors, making it incredibly durable for everyday needs.

However, when using Pyrex in the microwave, it is essential to be aware of certain precautions.

Since there are different types of PYREX products, they may have varying safety restrictions when it comes to microwaving.

Before purchasing any Pyrex product, be sure to check the logo. PYREX® is written with all capital letters and designates that it is either a vintage Corning Glass Works item or a new French one (two of the safest types of borosilicate on the market)

If the logo is not all in capital letters, then the glassware is likely made with tempered soda-lime glass. This type of Pyrex is heat resistant and can be used in the microwave but is not as safe as its borosilicate counterpart.

Say you take a Pyrex container out of the freezer and pop it into the microwave; this could easily result in an explosion.

On the other hand, using borosilicate PYREX has a high thermal shock resistance that prevents it from cracking or shattering, even when you abruptly change temperatures.

III. How to microwave Pyrex safely? 

Although Pyrex is microwave-safe, there are some important safety tips to keep in mind:

1. Ideal temperature to microwave Pyrex

The thermal resistance for American Pyrex is up to 572° F, whereas the thermal shock resistance of French Pyrex ranges from -4° F to ovens 464° F.

However, it is always wise to gradually warm up Pyrex dishes, jugs, cups, or bowls before exposing them to a drastic temperature difference. This could result in the Pyrex glass exploding.

2. Other guidelines for microwaving Pyrex

Follow the guidelines below to safely use Pyrex in the microwave:

  • To avoid breakage, never pour hot liquids into a Pyrex measuring cup if it has been chilled.
  • Always remember to never set a hot Pyrex dish on an overly cold surface; it may cause the glassware to shatter.
  • Heating a Pyrex cup in the microwave without any content can have severe consequences, such as cracking and shattering.
  • To ensure a safe microwave dish, look closely at the packaging and manufacturer’s recommendations. If you do not see “microwave-safe” on the label, it is best to avoid that product altogether.

IV. How long can you microwave Pyrex? 

When using any material in the microwave, it is always important to follow the instructions provided by the manufacturer.

However, Pyrex cookware is rigorously tested for up to 1000 hours before it’s released onto the market, so you can rest assured that your Pyrex bowls are able to withstand regular use in a microwave. With such stringent testing protocols and results exceeding expectations, there should be no worries about how long you can microwave your Pyrex cookware!

Nonetheless, to ensure safe handling, it is always important to read the directions and warnings on the packaging.

V. Can you microwave Pyrex lids? 

Glass lids: According to the official Pyrex website, the Pyrex glass lids manufactured with the same material as their containers are safe to use in your microwave oven.

Plastic lids: It is recommended to remove the lid before placing your Pyrex container in the microwave if it is a plastic Pyrex lid.

In a conventional oven: Pyrex lids are not oven-safe, so they should not be placed in conventional or convection ovens.

VI. Is the Pyrex oven safe? 

Yes, Pyrex is safe to use in a conventional oven if used with care.

However, direct contact with heat sources can cause Pyrex glass to shatter or break; thus, it is not recommended for use under the broiler or in a toaster oven.

Moreover, remember to preheat the oven before placing Pyrex cookware inside. Putting cold glassware directly into a hot oven may cause the glass to break due to thermal shock unless it is borosilicate.

VII. Advantages and disadvantages of using Pyrex

Here are some advantages and disadvantages of Pyrex cookware:

1. Advantages

The main advantages of using Pyrex glassware include its durability, versatility, and safety.

Pyrex is heat-resistant and can withstand high thermal shock temperatures. This makes it perfect for a variety of uses, from cooking to baking and microwaving.

Pyrex is made from non-toxic materials, and it does not contain any lead or cadmium. You can use it without fear that the glass may leach dangerous chemicals into your food.

Moreover, it is environmentally friendly since it is also BPA-free. 

2. Disadvantages

On the downside, Pyrex’s latest releases are made from soda lime glass, unlike the borosilicate it was originally manufactured with. This has caused a decrease in its thermal shock resistance capacity, requiring extra caution when microwaving any Pyrex product; be sure to adhere closely to all instructions!

Pyrex can be brittle and prone to shattering if not handled with care. Direct contact with extreme temperatures or sudden temperature changes can cause the glass to crack or break.

Direct, intense heat in a single spot can cause Pyrex to shatter. So, never use Pyrex cookware on induction or electric cooktops. You also cannot employ this cookware if your recipe calls for both microwave and hob cooking.

Pyrex is often more expensive than other types of cookware, so it may not be the best option if you are looking to save money.

VIII. How to clean Pyrex? 

Pyrex glassware is very easy to clean and maintain. You can try cleaning these utensils the regular way with your own hands or pop them in a dishwasher. Here’s how you go about both methods:

1. Clean them with your hands

Simply use a damp cloth or sponge to wipe away dirt, food residue, and stains from the surface. For tougher spots, you can use a mild detergent with warm water.

Avoid using abrasives or harsh cleaning products on your Pyrex cookware, as these may scratch the surface.

Make sure to properly dry your Pyrex glassware after cleaning. This will help prevent streaks and spots from forming on the surface.

2. Use a dishwasher

When it comes to dishwasher cleaning, you can safely put Pyrex in the machine with a non-citrus detergent and select a light cycle. 

For extra care, use the top rack of your dishwasher for added protection from any strong jets or heated dryers.

IX. Tips for using Pyrex safely

Here are some of the tips to keep in mind when microwaving with Pyrex:

• Always read the instructions and warnings provided on the packaging.

• Do not use plastic lids of your Pyrex cookware in the microwave.

• Place a paper towel or dishcloth between your bowl and the plate you microwave it on.

• Avoid sudden temperature changes with American Pyrex.

• Do not overfill the container.

• Check your food regularly and stir or rotate if necessary.

• And lastly, use oven mitts when handling hot glassware.


Pyrex is a great addition to any kitchen; with the right care, it can provide years of safe use. Ultimately, it is always important to read the manufacturer’s instructions for proper use when dealing with Pyrex or any glassware. With these tips in mind, you should have no problem safely microwaving with Pyrex.


1. What Pyrex dish is best for the microwave?

The best Pyrex dish for microwaving is the one made of borosilicate glass. These are known to be more heat-resistant and are better able to withstand sudden temperature changes. Look for the ones with handles to ensure safe and accident-free usage.

2. Will Pyrex melt in the microwave?

Pyrex is designed to withstand high temperatures and will not melt in the microwave, even when subjected to long heating times. However, sudden temperature changes can cause it to expand, contract, and break.

3. Is it safe to microwave cold Pyrex?

Yes, it is safe to microwave cold French Pyrex. However, it is important to preheat the oven before placing Pyrex cookware inside and to follow the manufacturer’s instructions for proper use. Additionally, you should avoid sudden temperature changes with American Pyrex to prevent it from cracking or breaking.

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