Exploding Myth: Pyrex in Microwave Is Safe

Pyrex is safe to use in the microwave as long as it’s labeled microwave safe. Pyrex glassware has been a staple in kitchens for over a century.

Its ability to handle high temperatures without shattering makes it a go-to choice for baking and cooking. But can you use it in the microwave? The answer is yes, as long as the pyrex is labeled microwave safe. Pyrex products that are not labeled for microwave use can still be used, but with caution and following specific guidelines.

In this article, we’ll explain how to safely use pyrex in the microwave, including precautions to take and tips for successful microwave cooking.

Exploding Myth: Pyrex in Microwave Is Safe

Credit: www.snopes.com

Understanding Pyrex Glassware

Pyrex glassware is one of the most popular kitchen glassware brands in the world. It is known for its durability and ability to withstand thermal shock. In this section, we will explain the composition of pyrex, how it works, and why it is a preferred choice for kitchen glassware.

Explanation Of Pyrex And Its Composition

Pyrex is a type of borosilicate glass that is made with a special combination of materials. The key ingredients of pyrex are silica, boron oxide, and aluminum oxide. Here is a breakdown of the composition of pyrex:

  • Silica (80%): The primary ingredient in pyrex is silica, which is found in sand. It is an essential element for making glass and gives pyrex its hardness and durability.
  • Boron oxide (13%): The addition of boron oxide reduces the expansion rate of pyrex, making it resistant to thermal shock.
  • Aluminum oxide (4%): Aluminum oxide provides pyrex with thermal shock resistance and durability.
  • Other ingredients (3%): The remaining 3% of pyrex includes minor amounts of other elements such as potassium oxide and sodium oxide.

How Pyrex Glassware Works And Is Designed To Withstand Thermal Shock

Pyrex glassware is designed to withstand extreme temperature changes without cracking or breaking. It can be heated and cooled quickly without damaging the glassware. Here’s how it works:

  • Thermal shock resistance: Pyrex glassware is designed to resist thermal shock. This means that it can handle rapid temperature changes without breaking.
  • Expansion coefficient: Pyrex has a low coefficient of thermal expansion, which means it does not shrink or expand quickly in response to temperature changes.
  • Extreme temperatures: Pyrex glassware can handle temperatures ranging from -40°f to 572°f (-40°c to 300°c).

Why Pyrex Has Been A Preferred Choice For Kitchen Glassware

There are many reasons why pyrex has been a preferred choice for kitchen glassware. Here are just a few:

  • Durability: Pyrex glassware is known for its durability and long-lasting performance. It is resistant to scratches, chips, and stains.
  • Versatility: Pyrex glassware can be used for a variety of purposes, including baking, cooking, and serving. It is microwave and oven safe, making it a versatile choice for any kitchen.
  • Easy to clean: Pyrex glassware is dishwasher safe, making it easy to clean and maintain.
  • Health and safety: Pyrex glassware is non-toxic, non-reactive, and does not contain any harmful chemicals. It is a safe and healthy choice for food preparation and storage.

Pyrex glassware has been a popular choice for kitchens around the world for over a century. Its unique composition and design make it a versatile, durable, and safe choice for cooking, baking, and serving. So, next time you reach for a pyrex dish, remember why it has become a preferred choice for kitchen glassware.

Microwave Ovens And How They Work

Pyrex In Microwave

Pyrex is a popular brand that manufactures cookware, including glass bowls and dishes. These products are known for their durability and versatility, making them a staple in many kitchens. However, a common question that arises among users is whether pyrex glassware is safe for use in microwave ovens.

How Microwave Ovens Use Radiation To Heat Food

Microwave ovens use a type of electromagnetic radiation called microwaves to heat food. This radiation penetrates the food and causes the water molecules in it to vibrate rapidly. As a result, the molecules create heat, which in turn cooks the food.

How Microwaves Affect Different Types Of Materials

Microwaves can affect different types of materials in different ways. While they can heat and cook food, they may also cause other materials to overheat or melt. In the case of pyrex glassware, the material is designed to withstand high temperatures and rapid changes in temperature, which makes it an ideal choice for use in a microwave oven.

The Reasons Why Certain Materials Are Not Microwave-Safe

Some materials are not safe for use in a microwave oven. Here are some of the reasons why:

  • Metal: Microwave radiation cannot penetrate metal, which means that metal objects can cause sparks and even start a fire in a microwave oven.
  • Styrofoam: This material can melt when exposed to high temperatures, which can contaminate the food and damage the microwave oven.
  • Plastic: Certain types of plastic can release harmful chemicals when heated in a microwave oven, which can seep into the food and cause health issues.
  • Glass: Not all types of glass are safe for use in a microwave oven. Some types may shatter or crack when exposed to high temperatures.

Pyrex glassware is safe for use in a microwave oven due to its ability to withstand high temperatures and rapid temperature changes. However, it’s always best to check the manufacturer’s instructions before using any type of material in a microwave oven to ensure your safety and avoid exposing yourself to any unnecessary health risks.

The Pyrex-Microwave Controversy

Pyrex In Microwave: The Pyrex-Microwave Controversy

Glass cookware has been a kitchen staple for decades, and the pyrex brand has been a favorite among home cooks for its reliable quality. However, over the years, concerns have arisen about the safety of using pyrex cookware in the microwave.

The pyrex-microwave controversy has been a topic of discussion for some time, and in this blog post, we’ll explore why there are concerns and whether they are justified.

Why Pyrex And Microwaves Are Believed To Be A Dangerous Combination

The primary concern regarding pyrex and microwaves revolves around the potential for the glass to shatter. This can happen when extreme temperature changes occur, such as when the hot pyrex is taken out of the oven and placed on a cool surface or when it’s subjected to uneven heating in the microwave.

The sudden change in temperature can cause the glass to expand and contract rapidly, leading to cracks and, in extreme cases, shattering.

Exploring The Study That Started The Pyrex-Microwave Controversy

The controversy surrounding pyrex and microwaves is largely based on a study conducted by consumer reports in the 1980s. The study claimed that pyrex glassware was prone to shattering when used in the microwave, and it caused widespread panic among consumers.

As a result, corning, the company that makes pyrex, changed the type of glass used in their cookware from borosilicate to tempered soda-lime glass, which is believed to be less resistant to sudden temperature changes.

Debunking The Scientific Flaws In The Study

Despite the findings of the consumer reports study, there are several scientific flaws that have been pointed out over the years. For instance:

  • The study used pyrex glassware that was four decades old and made of borosilicate glass, which is more resistant to thermal shock than tempered soda-lime glass.
  • The sample size was limited, with only a small number of pieces of cookware tested.
  • The testing methods used were not standardized, and the microwave ovens used were older models with varying wattages.

Moreover, subsequent studies conducted by corning and other independent bodies have not found any evidence to support the claims made by the original study. They concluded that when used correctly and in good condition, pyrex cookware can be safely used in the microwave.

While the pyrex-microwave controversy has caused concern among consumers, the scientific evidence does not support the notion that pyrex is inherently dangerous to use in the microwave. However, it’s worth bearing in mind that extreme temperature changes can cause any glass to shatter, and it’s important to follow the manufacturer’s guidelines for safe use.

Pyrex Glassware And Microwave Safety

Understanding The Various Pyrex Glassware Lines And Their Microwave Safety

Pyrex is a brand of heat-resistant glassware that has been around for more than a century. Their glass containers are a popular choice for reheating food, particularly in the microwave. However, not all pyrex glassware is created equal, and not all pyrex products can be safely used in the microwave.

Here’s what you need to know:

  • Pyrex has multiple lines of glassware, including borosilicate glass, soda-lime glass, and tempered glass.
  • Borosilicate glass is highly heat-resistant and can withstand rapid temperature changes, making it safe for use in the microwave, oven, and freezer. It’s often labeled as “pyrex original” or “pyrex classic.”
  • Soda-lime glass is not as heat-resistant as borosilicate glass and can crack or shatter when exposed to sudden temperature changes. It should not be used in the microwave. It’s often labeled as “pyrex basics.”
  • Tempered glass is heat-treated to increase its strength but can still break if subjected to sudden temperature changes. It is microwave-safe but may not be labeled as pyrex.

Tips On How To Use Pyrex Glassware In The Microwave Safely

Microwaving pyrex glassware is generally safe, as long as you follow a few key tips:

  • Always check the label to make sure the pyrex glassware is microwave-safe and follow any usage instructions listed.
  • Avoid using heavily chipped or damaged pyrex glassware in the microwave, as this can increase the risk of breakage.
  • Never put pyrex glassware directly on a stove burner, as this can cause it to overheat and crack.
  • Avoid using pyrex glassware that has metal trim or decorations in the microwave, as this can cause arcing (sparks) that can damage the container or the microwave.

Other Safety Guidelines For Using Pyrex Glassware

In addition to the microwave-specific tips above, there are a few other guidelines to keep in mind when using pyrex glassware:

  • Never put hot pyrex glassware in cold water or vice versa, as this can cause it to crack or shatter.
  • Let hot pyrex glassware cool down before washing it or putting it in the fridge or freezer.
  • Avoid subjecting pyrex glassware to sudden temperature changes. For example, don’t put a hot pyrex dish straight into the fridge or freezer, as this can cause the glass to crack.
  • Be careful when handling pyrex glassware, especially when it’s hot or has just come out of the microwave or oven.

By following these guidelines, you can safely use pyrex glassware in the microwave and other settings. Always check the label to make sure you’re using the right type of pyrex glassware for your needs and take care when handling it to avoid breakage or injury.

Frequently Asked Questions Of Pyrex In Microwave

Can Pyrex Go In The Microwave?

Yes, pyrex is microwave safe as long as it doesn’t have any metal on it.

Can Pyrex Explode In The Microwave?

Yes, pyrex can explode in the microwave if it has any cracks or nicks in the glass. It’s important to inspect it carefully before using it in the microwave.

How Long Can I Microwave Pyrex?

Pyrex can be microwaved for up to 10 minutes at a time. It’s always best to use short intervals and check in between to make sure it’s not overheating.

Can I Use Pyrex To Bake In The Microwave?

Yes, you can use pyrex to bake in the microwave. Pyrex is safe for use in both conventional and microwave ovens.

Is Pyrex Better Than Plastic For Microwaving?

Yes, pyrex is a better option than plastic for microwaving. Plastic can melt or release harmful chemicals when heated, whereas pyrex is made of durable glass that can withstand high temperatures.


Microwaving pyrex can be a time-saving and convenient kitchen hack, but it’s important to follow some basic safety guidelines. Always check the label to ensure it’s microwave-safe and don’t expose it to sudden temperature changes as it may cause them to shatter.

Keeping these guidelines in mind will allow you to safely and efficiently use pyrex in your microwave. While there are some risks associated with microwaving any type of glass, pyrex’s durability and ability to withstand high heat make it a popular choice for cooking and reheating food.

This versatile glassware is not only functional but also aesthetically pleasing, so it’s worth investing in quality pieces that will last for years to come. With these tips in mind, you can confidently use pyrex in your microwave without worry, making your kitchen a more convenient and efficient space.

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