Is your Pyrex exploding? A friend of mine from high school was baking something in Pyrex glassware. It exploded in her oven.
I own a lot of Pyrex and a very expensive Dacor double oven. My young daughter likes to peek in the oven window to see what’s going on, so naturally, I started to investigate.
Plus, what if you are in a vacation rental with a fully stocked kitchen that includes Pyrex baking dishes? Should you use them? We’ll tell you what to know before making that decision.
What’s Happening With Pyrex
It turns out that this Pyrex exploding phenomenon is more common than you think. (Since I’ve written this post, we’ve also had Duralex Picardie glasses explode in our dishwasher.)
I read a story about a woman who opened her oven at the exact same time her Pyrex casserole dish exploded. The shards lacerated her face, but miraculously, she closed her eyes just in time.
I read a story about someone who opened her oven after a pan had exploded. Hot glass flew out and burned the nearby carpet.
Another guy had it happen while washing his Pyrex in a sink full of water. He felt a burning sensation in his finger, took it out of the water, and had a ¾ inch piece of glass lodged in his finger.
Glass Composition
Some people claim that the reason this is happening is that Pyrex changed the formulation of the glass from borosilicate to soda lime. World Kitchen, the company who currently owns Pyrex, argues that this change shouldn’t matter and that soda lime is stronger.
Some believe that the older Pyrex, which I’ve always preferred due to its squarer edges, is safer. I’m not a scientist, so I can’t vouch for either claim.
To me, the composition is irrelevant, because whatever it’s made out of can shatter into hundreds (thousands?) of pieces without warning.
Thermal Shock
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Thermal shock occurs when you take something from a cold environment to a hot one. It is acknowledged that Pyrex can explode when this happens.
Even the people at trusty people at Cooks Illustrated have written about their experiences with exploding Pyrex in their test kitchens. I make-ahead meals from their cookbooks (like enchiladas and lasagna), freeze them, and then bake at a future date (my favorite cookbook is their Complete Make-Ahead Cookbook). I used to do this primarily in Pyrex glassware.
Pyrex Glassware Safety and Usage Instructions
Have you actually read the instructions that come with your Pyrex dishes? Odds are you ripped off the paper wrapper thinking, it’s glass and a no-brainer.
There’s a long list of things you should and shouldn’t do with your Pyrex. Well, check this out (see link above for full instructions):
Mine is scratched and I bet yours is to some degree, too. What I might think of as a minor scratch, someone else might consider “severe.”
How can anyone test my pan after it explodes into hundreds of pieces?
Is Your Pyrex Exploding? Take Action.
Decide if you’re diligent enough to manage your Pyrex and other glassware. You should inspect it each time you bake. I’m a busy mom and am not confident I will do this. I’m not trying to be alarmist, but I’m swapping my Pyrex out for ceramic or metal bakeware. To me, it’s just not worth the risk for the relatively minimal cost it will take to switch to new pans.
The people in the stories I refer to all claim that thermal shock was not involved and that their explosions were totally out of the blue. This is what concerns me. It’s possible they had Pyrex glassware in perfect condition that exploded.
Pyrex has addressed the situation on its website in a Truth About Pyrex Glass section. You may read stories about Pyrex glassware exploding on Consumer Affairs (where two of my stories above are from).
There are also articles online calling this a hoax, which I don’t believe, given that it just happened to a very well-educated friend of mine.
FAQs About Pyrex Breaking
For those of you who skim-read…
Can You Put Pyrex Glass in the Oven?
You can usually put Pyrex glass in the oven. However, there is an important factor to keep in mind. Your Pyrex is not resistant to thermal shock, so you should not move it from one temperature extreme to the other.
For example, do not take your Pyrex out of the refrigerator and immediately put it in the oven. Instead, let it cool down and get closer to room temperature before placing it in the oven.
Can You Use Pyrex on the Stovetop?
While Pyrex glass can handle intense heat, it is not designed for the stovetop. Warnings and instructions unanimously guide users never to use Pyrex on the stovetop.
Will Pyrex Crack From Hot to Cold?
Pyrex is not resistant to thermal shock; therefore, there are instances where Pyrex glassware can explode when moved from a hot environment to a cold one and vice versa. In short, avoid exposing your Pyrex to extreme temperature changes at all times.
Photo credit: Flickr/technodad
Katie Dillon
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