Listen to this PodcastMore 60-Second Science
When Pyrex cookware first came out, it was advertised as "icebox to oven." Because it was made of borosilicate glass, which could weather large temperature changes without undergoing thermal shock, and shattering. But today, American Pyrex and Anchor Hocking dishes are made of soda lime silicate glass, which is more prone to shatter. So says a report in the Bulletin of the American Ceramic Society. [R. C. Bradt and R. L. Martens, Shattering Glass Cookware]
Researchers calculated that a rapid temperature change of just 100 degrees Fahrenheit could fracture the new glass—compared to 330 degrees for the old stuff. They say that means it's possible to break a glass measuring cup with boiling water. Or to explode a cool casserole dish by sliding it into a hot oven.
Manufacturers say they temper the new glass to make it stronger. And researchers did find some evidence of that. But they believe that the heat treatment was inadequate. Because in lab tests, the cookware exploded into large glass shards, rather than tiny pieces, as tempered auto glass does.
As the saying goes, if you can't stand the heat, stay out of the kitchen. If this research is accurate, the heat is on this cookware.
—Christopher Intagliata
[The above text is a transcript of this podcast.]
See what we're tweeting about
3 Comments
Add CommentWhat is the date on this article? This was news a decade or two ago. When the glass making left the US to be made elsewhere, it started shattering. The old stuff I have still works. The couple of new pieces broke right away.
Reply | Report Abuse | Link to thisJust another business example of the Numbers People dominating what ought to be normal human concern for the welfare of others. So, when might this vulnerable glass shatter, when no one is around or when of necessity it is being handled by a naive consumer i.e. someone with years of experience using "Pyrex" or someone w/o any experience; by swift of Law what had been made of borosilicate glass and copyrighted as "Pyrex" is now soda lime silicate glass but legally also called "Pyrex". I understand that the original manufacturer Corning still sells the original "Pyrex" still sold under that name but only in lab ware that is all but unavailable in the normal retail outlets used by =-99% of consumers. MORAL: While corporations (according to our dishonorable Supreme Court Jurists) are legally people, I know for a fact that the only human emotion they feel is MONEY so until some other fix is legal, we members of the human public should be honor bonded to go out of our way and regardless of our monetary expenses to sue those F----n B-----ds until they have become sufficiently drained of their green blood and it begins to drain red.
Reply | Report Abuse | Link to thisWhen my grandmothers passed away, I grabbed every piece they had and it definitely holds up much better. I had a piece that I purchased when I married in the 1990s shatter taking it out of the oven (goodbye dinner) and remember being shocked. I guess we found the new American heirloom!
Reply | Report Abuse | Link to this