A Warning that Pyrex Glass Cookware Can Explode- Mostly Fiction!

A Warning that Pyrex Glass Cookware Can Explode- Mostly Fiction!

Summary of eRumor:
The eRumor talks about what it describes as “exploding Pyrex.”  It says that the popular ovenware has been unsafe ever since the Corning Company sold the Pyrex brand to a company named World Kitchen.  It also claims that the product became inferior because it was now made of soda lime glass instead of borosilicate glass.  One final claim is that World Kitchen is not an American company.

The Truth:

We don’t know who the original author is of this email or his or her motives, but there is a lot said about Pyrex and the company that makes Pyrex that is incorrect.

Pyrex is one of the most widely used products in American households and has been used safely for decades.
According to World Kitchen, the makers of Pyrex, there has never been a recall of Pyrex or any concern about its safety on the part of the Consumer Product Safety Commission.
Like all glassware, Pyrex needs to be used according to instructions.  At the time of our investigation we found on the Pyrex website an advisory to consumers not to subject the product to extreme temperature changes, such as putting a Pyrex dish directly on a burner, under a broiler, adding liquid to a hot dish or placing a hot dish on a cold or wet surface.  Under those circumstances the glass can break.
The claim that the current makers of Pyrex abandoned borosilicate glass in favor or poorer quality soda lime glass is false.
World Kitchen told TruthOrFiction.com that Pyrex has been made from heat-strengthened soda lime glass for about 60 years and that the switch was first made by Corning, not World Kitchen.  The company added, “Consumers should know that soda lime glass, such as that used to make PYREX glass bakeware, is significantly more resistant to breaking on impact than borosilicate glass and comparably resistant to breakage caused by severe temperature changes.”

It is also false that World Kitchen is not a U.S. company.  It is an American firm and Pyrex is manufactured in the U.S.A..

Posted instructions from the Pyrex website

Any glass bakeware product can break if it is not used properly. For that reason, we want to remind consumers to review the PYREX® Safety and Usage Instructions provided with our products. While not a substitute for reviewing the entire Safety and Usage Instructions, set forth below are selected highlights.


NEVER use on top of the stove, under a broiler, in a toaster oven, or place over oven vent or pilot light. AVOID severe hot to cold temperature changes, including:
DO NOT add liquid to hot dish. DO NOT place hot dish or glass cover in sink. DO NOT immerse hot dish in water. DO NOT place hot dish on cold or wet surfaces. Handle hot ovenware and glass covers with dry potholder. ALWAYS add a small amount of liquid to the vessel prior to baking foods that release liquids while cooking. DO NOT overheat oil or butter in microwave. Use minimum amount of cooking time. DO NOT use or repair any item that is chipped, cracked or scratched.


To loosen baked-on-food, allow glass to cool, then soak. If scouring is necessary, use only plastic or nylon cleaning pads with nonabrasive cleansers.

WARNING: Failure to follow these instructions can cause immediate or later breakage which can result in personal injury or property damage.

Posted 10/20/09   Updated 11/21/13