My Pyrex bowl just exploded with no warning!

July 22, 2011 12:32 AM

A Pyrex bowl just exploded all over my kitchen out of nowhere! What happened?

There is some raw chicken in it that was being mixed with spices, and everything has been at room temperature - no freezing, no heating. I walked away for a minute and there was a HUGE cracking noise, and then the bowl just spontaneously exploded into many pieces. Why did this happen? I'm in Southern California, but there was no quake or anything. And it's a moderate temp - not too hot or cold. I just googled "Pyrex explosion" on google and a lot comes up, but mostly in regards to temperature changes. Has this just randomly happened to anyone else? When a bowl is just at room temp?

posted by emily37 to Food & Drink (34 answers total)

This used to be quite common, much less so recently. Was it a real Pyrex bowl, or a cheap copy?
posted by devnull at 12:35 AM on July 22, 2011

another clarifying question - clear pyrex or milk glass?
posted by nadawi at 12:50 AM on July 22, 2011

Pyrex cookware is tempered soda-lime glass. Some types of inclusions in tempered glass can result in invisible or nearly invisible fractures that can open in the (apparent) absence of external stress. The risk for shattering is higher with big temperature differentials or shifts, but even without a visible chip, split or imperfection, tempered glass cookware can break suddenly.
posted by gingerest at 12:51 AM on July 22, 2011 [5 favorites]

Here's a Consumer Reports report on the shattering Pyrex problem.

Short answer: the formula has been changed from borosilicate to tempered soda lime glass. Tempering is good for automobile windshields. It isn't so great for stresses caused by fast temperature changes, such as touching a hot Pyrex bowl to a cold surface.
posted by eye of newt at 1:03 AM on July 22, 2011

Did you buy your Pyrex at a discount retailer (i.e. Walmart or Target)? It's most likely a cheaper version, as eye of newt explains, that is prone to shattering.
posted by halogen at 1:10 AM on July 22, 2011

Interesting side effect of the formula change:

"When World Kitchen took over the Pyrex brand, it started making more products out of prestressed soda-lime glass instead of borosilicate. With pre-stressed, or tempered, glass, the surface is under compression from forces inside the glass. It is stronger than borosilicate glass, but when it's heated, it still expands as much as ordinary glass does. It doesn't shatter immediately, because the expansion first acts only to release some of the built-in stress. But only up to a point.

One unfortunate use of Pyrex is cooking crack cocaine, which involves a container of water undergoing a rapid temperature change when the drug is converted from powder form. That process creates more stress than soda-lime glass can withstand, so an entire underground industry was forced to switch from measuring cups purchased at Walmart to test tubes and beakers stolen from labs."

Popsci.com - "They Sure Don't Make Pyrex Like They Used To: A change to heat-resistant glass has had explosive effects"
posted by sharkfu at 1:27 AM on July 22, 2011 [1 favorite]

Response by poster: Thanks for the responses so far! It was real Pyrex, not a knockoff, and it was a clear bowl. I purchased it probably in 2008, and probably at Target or Amazon. I guess I ended up with the cheap soda lime glass! It was just so strange though, that it exploded at room temperature with literally no temp change. The oven wasn't even on, and it is a temperate 60-something degrees both inside and outside the house.

Anyone know if you can still buy the borosilicate Pyrex in the US? I read online that Europe never made the material change. I always wondered why Pyrex was so inexpensive - now I know! I feel like I now have to go scouring my local thrift stores for vintage Pyrex pieces!
posted by emily37 at 1:41 AM on July 22, 2011 [2 favorites]

Metafilter's own Ahab might be the man to ask.
posted by Pinback at 1:48 AM on July 22, 2011 [1 favorite]

Yeah, maybe. But I'm sitting here fuming about the repetition of the whole world kitchen debate and trying to put something reasonable together..

Firstly, gingerest has a pretty fine explanation. Except that I think it applies to borosilicate pyrex as well - because that was annealed or tempered too.

Secondly, to repeat what I think I said in the thread pinback just linked, flaws and cracks develop over time. Every time a piece of glass kitchenware gets bumped on a bench or tapped with a spoon, you've got the potential to create an internal crack. These spread. Then, eventually, tiny vibrations or variations in temperature are enough to trigger a big crack or "explosion."

(I don't think I have a single piece of 1920s or 30s borosilicate pyrex without at least one visible flaw. Whether those are manufacturing flaws or have developed over time is kind of irrelevant. They've all got the potential to produce larger cracks and shattering.)

Secondly, if you want really borosilicate, I think there were a couple of French brands made by Arc or Durand mentioned in the thread pinback linked. Or you could buy vintage, but soda lime really was introduced a long while ago and age brings flaws, so you're probably safer buying it new and online.
posted by Ahab at 2:23 AM on July 22, 2011 [6 favorites]

*really want. Ugh.
posted by Ahab at 2:34 AM on July 22, 2011

Thirdly. Ugh.
posted by spicynuts at 3:35 AM on July 22, 2011

Pyrex kitchen glassware manufactured for sale in the United States is made at the World Kitchen facility in Charleroi, Pennsylvania.

Pyrex products for the European Union are made at a factory in France. EU products and laboratory glassware continue to be made of borosilicate glass.

So your solution is to buy Pyrex when on holiday in Europe, or use Amazon.co.uk and have it shipped.
posted by Lanark at 4:07 AM on July 22, 2011

Happens sometimes, but has for most of my lifetime. My family has lots of Pyrex stuff bought over the last, shoot, forty years? Fifty? A really long time. We've had two crack, and both were older (judging from the fade-out of the measuring lines.) It was a "sudden bump" thing, not directly connected to a recent temperature change.

As long as it's made of glass, this is a potential problem.
posted by SMPA at 4:07 AM on July 22, 2011

The Pyrex Collective has some reports of exploding (newer) Pyrex doing that, including reports that don't involve any temp changes. (I've also read at least one case of vintage Pyrex exploding in the cupboard, although in that case the bowl was at the bottom of a stack and the blogger thought pressure might have been a factor.)
posted by pie ninja at 4:09 AM on July 22, 2011

or on preview what Ahab said, looks like wikipedia is wrong
posted by Lanark at 4:13 AM on July 22, 2011

Search for and buy "Pyrex flameware" on ebay. That's the real stuff from the 1940's. Dusty blue color and goezinta the microwave.
posted by andreap at 4:28 AM on July 22, 2011

..thirdly.. Rub it in spicynuts, rub it in..

On just a little bit of a tangent, seemingly spontaneous shattering happens to art and studio glass as well. The examples noted in this thread on the Glass Message Board are a real mix of glass formulas. Some are obviously temperature related, but some not. Ivo Haanstra's opinion re annealing a few comments down is distinctly authoritative. He writes books about this kind of thing.

And.. nthly.. another couple of choices for tough as nails vintage replacements: The Pyrex Visions range was made from a clear (brown or cranberry coloured) vitro ceramic and is stovetop safe (ie it's very resistant to thermal shock). The brown stuff turns up in thrift stores all the time, but the cranberry coloured items are a bit rarer, and you'll probably need to buy them off ebay. Then there's Corningware. It's another vitro ceramic and it really is tougher than just about anything except metal, but it doesn't come in clear and I've never seen round bowls. Ebay again.
posted by Ahab at 5:15 AM on July 22, 2011 [1 favorite]

Regarding the recommendations to "buy Pyrex when in Europe" – in France, it is not only sold under the brand name "Pyrex" but also under the brand name "Arc" or "Arc International". Easy enough to identify since it's glass, though you do want to stay away from cheaper knockoffs (generally easy to identify since they're also noticeably thinner – the good stuff has a real heft to it). You can find it in regular ol' supermarkets and on Amazon.fr, though I don't know if they'll ship non-book items to the US (they don't from the US to France). I love mine, FWIW, never had a problem in 12 years of use.
posted by fraula at 5:16 AM on July 22, 2011

eye of newt is correct. Corining no longer makes pyrex and the formula has been changed. I had a 9X13 pyrex pan explode on me. It is my understanding if you want "real" pyrex, purchase the old vintage white glass pyrex. I have since thrown out pyrex that was "designed" for oven use. Now that I am reading your question I will start to work on replacing my other pieces.
posted by BuffaloChickenWing at 6:01 AM on July 22, 2011

Did the chicken come out of a refrigerator? That might be the source of the temperature change.
posted by cali59 at 6:04 AM on July 22, 2011

I had this happen last year with a piece of borosilicate Pyrex from the 50s or 60s. I left it sitting on the kitchen counter empty (after it held some cashews for snacking or something like that, no temperature changes from cabinet to use to counter) and an hour or two later I heard a terrible noise and it shattered. Scared the bejeezus out of me. Also I was quite irate with it because, hello, bowl, you're Pyrex! Pyrex doesn't shatter!

The consensus I got, asking some materials scientist types, was "Probably tiny cracks" or "sometimes that just happens." Followed by stories of exploding labware.
posted by Eyebrows McGee at 6:51 AM on July 22, 2011 [1 favorite]

This happened to me once, only it was a pyrex lid to a pot. It was sitting at room temperature in a drain basket and just spontaneously shattered. Not as in a few cracks—the entire thing just dissolved into M&M-size pieces. That's what fascinated me most, actually; the pieces were all fairly uniform in size and none of them were especially jagged or sharp. I'd never seen glass/pyrex/anything shatter in that manner.

It hadn't undergone any recent temperature changes and, to my knowledge, nothing was putting pressure on it at the time. The best explanation I could come up with was that some freak combination of vibrations from the dishwasher (which was running at the time a few feet away) had triggered the sudden eruption of a tiny crack or imperfection.
posted by dephlogisticated at 7:23 AM on July 22, 2011

Anecdata: I "exploded" a pyrex casserole dish making lasagna in the oven as a teenager. Big boom, then cheese, tomato sauce, and broken glass rolling down the dies of the oven. I was in big trouble because mom thought I used a "regular" glass casserole dish instead of an oven safe one, whatever that meant.

I'm totally showing her this thread. Twenty years ago, but hey, I'm owed an apology!
posted by juniperesque at 7:28 AM on July 22, 2011

Now I'm scared to use my pyrex.

Not to piggyback, but is it dangerous when it explodes, or does it just shatter a bit. I just want to make sure I'm safe when using. I bake a lot with my children and I'd hate for it to explode on my son or daughter.
posted by Sweetmag at 7:34 AM on July 22, 2011 [1 favorite]

Now I'm scared to use my pyrex.

You are much more likely to be in a car accident than to injure you kids while baking with Pyrex. I'm all for minimizing risk, but everything has some danger, including baking (hot! what if they get into the knives! dropping a bowl on your foot!).
posted by anastasiav at 8:58 AM on July 22, 2011

dephlogisticated writes "the pieces were all fairly uniform in size and none of them were especially jagged or sharp. I'd never seen glass/pyrex/anything shatter in that manner. "

This is how tempered glass breaks. It's considered a safety feature when it is used for automotive glass.

Sweetmag writes "ut is it dangerous when it explodes, or does it just shatter a bit."

The glass itself doesn't have much in the way of velocity so you won't get hurt from glass flying at you. IE: it doesn't really explode like a grenade. It is more like it disintegrates in place. The only real danger is from hot contents splashing all over if it happens to occur while you are holding the container. Oh and the pieces are still somewhat sharp so one wants to be careful when cleaning up.
posted by Mitheral at 9:18 AM on July 22, 2011 [1 favorite]

I had a similar thing happen with a new set of Pyrex (one dish exploded) so I contacted their customer support. They were very nice and offered to not only replace the entire set with a new one, but also gave me $50 credit to spend in their online store (incl free shipping).
posted by buckaroo_benzai at 9:20 AM on July 22, 2011

So interesting!

I wonder if I have bowls from before and after .I haven't sensed a difference in the actually material, but the shape is a little different - the newer ones have wider "mouths" which allow bowls to nest a little more.

I've been putting hot soup in the bowls and moving them directly to the freezer about once a week for the passed year without any consequences so I guess they're ok.
posted by jander03 at 9:58 AM on July 22, 2011

"is it dangerous when it explodes, or does it just shatter a bit."

Mine had two or three big pieces, and a bunch of tiny pieces. None were very sharp, and none "flew" very far from the location of explosion. (Like I only found a couple of tiny pieces on the floor, even; virtually all were still on the counter.)

Honestly the shock of the NOISE was much more upsetting than the actual broken glass ... though I wasn't in the room. But it looked certainly no worse than when I've dropped and shattered a juice glass, and far far better than the time I knocked a drying rack with 8 champagne flutes onto the ground and shattered them all at once.
posted by Eyebrows McGee at 10:10 AM on July 22, 2011 [1 favorite]

When I had to replace a Pyrex baking dish, I bought Marinex, which is Borosilicate. Amazon carries the line.
posted by fief at 10:16 AM on July 22, 2011 [1 favorite]

Sweetmag, mine have never "exploded". They've cracked dramatically and noisily, and I have ended up with sharp shards. That said, I like my vintage and antique stuff, I don't mind doing silly things and taking risks with it, and most of what I've killed was made in the sixties or earlier, so I'm probably not quite the right guy for your question.

But if I may, I do think there's some basic safety things you should be doing and not doing.

Unless it's marked for stovetop use, keep your pyrex away from flame (careful with the back of a gas oven). Watch the heat - I'd say 200-220°C is about the maximum for older pyrex or newer soda lime glass pyrex. Inspect your dishes for flaws, cracks chips and shelve them if you find any. Don't cook anything that will result in lots of fat boiling on the base of a dish - I get the sense it can get into cracks and expand. Take serious care to minimise thermal shock - don't transfer stuff straight from the fridge or freezer to the oven or vice versa, use a dry cloth or mitts to handle hot dishes, don't put a hot dish on a cold or wet cloth or surface.

Then, as always, there's the "Kids this is hot, we put it down and step back for a few minutes" angle. That's basic safety regardless of what your dishes are made.
posted by Ahab at 11:40 AM on July 22, 2011 [1 favorite]

A previous Ask Me about a tempered glass explosion.
posted by MsMolly at 2:34 PM on July 23, 2011

I lost a 9x13 pan once, and honestly it wasn't nearly as big a deal in terms of shrapnel or noise as it was in terms of, "Goddamn it, I paid fifteen dollars for those ribs and now I don't dare eat them what with the possibility of glass shards."

There was definitely thermal shock involved with my incident but my understanding is that this is a problem with all tempered glass - lots of people I know including me have destroyed borosilicate labware, Pyrex-branded and not, through thermal shock. ("Goddamn it, I spent fifteen minutes making that solution and now I don't dare use it what with the possibility of glass shards.")
posted by gingerest at 6:57 PM on July 24, 2011

I just had a glass bowl explode, fortunately in my refrigerator so that the mess was contained and we were forced to clean the fridge for once. But, the chicken salad in the bowl was room temp going into 40 degrees - should not be enough delta temp and we had done that a hundred times, as it was my favorite bowl. Arc bowl from Crate and Barrel. So it is not just the American made glass that explodes - French history is ever entwined with ours....
posted by cleowen at 10:05 AM on August 7, 2011