“Based on reports made to the company and the Consumer Product Safety Commission, less than one tenth of one percent of the millions of Pyrex products sold each year experience thermal breakage, and there has never been any recall of Pyrex glassware.”
Pyrex eventually switched to tempered glass most likely because boron is toxic and expensive to dispose of. Although tempered glass can better withstand thermal shock than regular soda-lime glass can, it's not as resilient as borosilicate. This is what causes the shattering reaction people are talking about.
The FTC took action against Instant Brands in 2023 charging that the company claimed that all its popular glass measuring cups were made in the United States, despite some measuring cups actually being imported from China.
It's due to the properties of the failure-prone junky tempered glass that's now used to make Pyrex rather than the traditional resilient borosilicate glass which was what made Pyrex, Pyrex.
The next time you go to cook dinner in a Pyrex pan, take a look at the labeling. Cookware with lowercase logos are usually made of soda-lime glass and should not be heated up in the oven or microwave to minimize risk of them breaking.
Baking glassware such as Pyrex dishes in usable condition should be donated to local thrift stores or otherwise reused. If unusable they should be thrown away in the trash. They should not be added to curbside recycling. They are made of a different material than glass bottles and jars.
As long as you follow the same guidelines above, vintage Pyrex is A-OK to go in the oven and can be used in oven temperatures up to 425ºF (and skip the broiler). There is one caveat to using your vintage Pyrex, though: Do not use any vintage dishes that are chipped or cracked—in the oven or otherwise.
Brittle materials like glass are much more vulnerable to thermal shock, because they break when their molecules quickly expand under heat or contract under cold.
The Pyrex formula changed in 2020. This change was made to make Pyrex glass stronger and better able to withstand temperature changes. The newly formulated Pyrex combines classic trusted heat resistance with improved thermal shock resistance, making it a better choice for glass cookware.
Borosilicate glass is the ultimate non-toxic choice. It's completely free from harmful chemicals like BPA, lead, or phthalates. No matter how hot or acidic your food gets, this glass stays clean and safe, giving you one less thing to worry about.
Everyone loves a good kitchen hack, and one of the most popular examples concerns glass cookware. Between Twitter, Reddit, and TikTok, there are hundreds of posts asserting that all-caps PYREX is the good stuff (aka, borosilicate glass), and all-lowercase pyrex is junk (aka, tempered soda-lime glass).
Corning divested itself of the Corning Consumer Products Company (now known as Corelle Brands) in 1998 and production of consumer Pyrex products went with it. Its previous licensing of the name to Newell Cookware Europe remained in effect.
Instant Brands, the company that makes Pyrex glassware, agreed to a settlement that banned it from making false claims and required it to pay money. The FTC is now using the money to provide refunds to eligible Pyrex customers. If you get a check, please cash it within 90 days.
Tempered Soda Lime. The various formulations for Pyrex glass have been a source of controversy for many, as well as a source of consumer lawsuits over shattering bakeware.
I contacted Pyrex to ask if there's an easy way to tell what material your Pyrex dish is made from, and the company had a simple answer: Look at the logo. If it's all caps “PYREX,” it's vintage, made of borosilicate. If it's lower case “pyrex,” it's new, and it's soda lime.
It is stronger than regular glass but it can still break or crack if it is dropped or hit hard. It is important to handle borosilicate glass with proper care to minimize the risk of breakage.
Corelle Brands is home to iconic, category-leading brands, including Instant™, Corelle®, Pyrex®, Corningware®, Snapware® and Chicago Cutlery®. We're passionate about delivering products that facilitate the joy we find in cooking and sharing food with family and friends.
To know whether or not your glass cookware is oven safe, look on the bottom of the dish for a Pyrex symbol or other notation that the glass is safe to put into the oven. If you cannot find a definitive marking, consult the manufacturer.
Historically, Corning owned the trademark to the PYREX and pyrex logos and they were used interchangeably on all Pyrex branded products. Corning later licensed the use of the names PYREX and pyrex to two different companies who now produce the glass cookware.
The maker of Pyrex glassware and Instant Pot multicookers has filed for bankruptcy protection, with as much as $1bn (£790m) in liabilities. Instant Brands blames high interest rates and weak demand for its problems. The company, which has more than 2,400 workers, plans to keep operating while it shakes up the business.
Because borosilicate is the most durable when it comes to withstanding temperature changes, it is generally considered the safest choice for glass bakeware.
The effects of thermal shock are great and can cause the glass to break. Even pyrex (like Pyrex) can break when improperly poured boiling water. To prevent the glass from breaking when exposed to boiling water, sudden and drastic temperature changes should be avoided.
DO NOT use or repair any glassware that is chipped, cracked or severely scratched. DO NOT drop or hit glassware against a hard object or strike utensils against it. Pyrex® Glassware can be used for cooking, baking, warming and reheating food in microwave ovens and preheated conventional or convection ovens.
What Makes Pyrex Special. "Pyrex continues to hold its value because most of us associate it with memories of family and holiday gatherings and memories from their childhood," Wright says. "The vintage designs and patterns of Pyrex evoke a nostalgia, which adds to its value for collectors.
The best way is to look at the bottom of the product. My vintage Pyrex, which is at least 40 years old, and definitely boro-silicate, reads “Not For Lab Or Stovetop Use - Corning N.Y. - U.S.A. - 516 - PYREX.” Newer products made of soda-lime glass do not read Corning N.Y., nor are they made by Corning.