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Pyrex explodes?

I was making wings tonight. I do the Alton Brown steam, cool, bake method. I put a rack on top of my Pyrex 9x12 glass baking dish, as I have done many times before. About 10 minutes in, the pyrex explodes. Sounded like a bomb went off in my oven. It looked like when a car window breaks. Entire oven covered in broken glass.
What the hell?

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  1. Over on the cookware section there has been a long posting on this subject.

    1 Reply
    1. re: escondido123

      Thanks. Obviously I'm not alone.
      My baking dish is (was) at least 20 years old.
      I'm surprised they can still sell this stuff.

    2. Much discussion of this topic has gone under the bridge. The older Pyrex apparently hasn't been known to explode as much as the newer stuff, something about China's unregulated manufacturing practices. My Pyrex is all old stuff from yard sales but after reading some of these posts I'm getting nervous about baking in it.

      BTW has anybody had Pyrex blow up in the microwave or is it just the thermal oven?

      12 Replies
      1. re: Querencia

        I use Pyrex in the micro, but never in the regular oven. I had a pie plate break when I took it out of the oven a few years ago. I've read so many examples of Pyrex breaking or exploding that I see no reason to take a chance.

        To the OP, there are threads about this on CH. Do a search for a thorough discussion. The original Pyrex has not been made of the original glass for many, many years. The currently made product is not as durable as that from former decades.

        Some people say they have no problems, but plenty of us have experienced what you have. I wouldn't use it in the oven. Why take a chance?

        1. re: sueatmo

          Pyrex® bakeware has been made of soda lime glass for more than 60 years. Borosilicate glass was used before that and is still used for laboratory glassware. Soda lime glass is used for home cookware because it is safer.

          1. re: GH1618

            +1. As for soda lime vs borosilicate glass safety. It is here and there. Borosilicate glass has better thermal shock durability, whereas World Kitchen claims that its soda lime glass has better physical durability.

            1. re: Chemicalkinetics

              The safety issue has to do with the characteristics of the shards after it breaks, not whether it breaks.

              1. re: GH1618

                Oh I see where you are getting at. Good point. My experience of broken labware (borosilicate) is that they are not that bad. Now, the broken crystal glass I had recently was pretty bad. Very big pieces, very tiny pieces, all shapes and sizes, and they were all very very sharp.

                1. re: Chemicalkinetics

                  You are very right. Someone I know picked up some broken glass with his bare hands and ended up getting a very bad infection from an almost invisible shard that went into his finger. Now I always wear rubber gloves when dealing with any broken glass.

        2. re: Querencia

          Pyrex® glass is made in the US, not China.

          1. re: Querencia

            <The older Pyrex apparently hasn't been known to explode as much as the newer stuff>

            Maybe people don't talk about it as much because the internet was not around. Or maybe because the glass formula changed from borosilicate glass to tempered soda lime glass.

            <something about China's unregulated manufacturing practices>

            Definitely nothing to do with China, since Pyrex glassware is still made in USA.

            <anybody had Pyrex blow up in the microwave or is it just the thermal oven>

            A lot less likely to blow up in microwave.

            1. re: Chemicalkinetics

              "... the internet (was) not around."

              Exactly. There is a reporting bias due to the easy availability of public forums such as this one. The more alarmed one is that a piece of glass should break, the more likely one is to go public with a complaint.

              Most people who use Pyrex® without problems don't bother to mention it. I am an exception. I will soon be making a couple of my traditional pumpkin pies in my 40-year-old (or so) Pyrex® pie plates, and I expect to report an uneventful baking experience.

            2. re: Querencia

              Mine did in the microwave. A small bowl that I was heating chicken broth in. Millions of little pieces. I've been nervous about using the stuff ever since, and I am careful about putting it down on a dry towel when hot.

              1. re: Querencia

                Pyrex is not and was not made in China. It is made in the US.


                And we use it extensively for storage without issue.

                1. re: Querencia

                  Querencia, I think you may have read about unregulated manufacturing practices in China here:

                  Already in that thread, it was pointed out that Pyrex glassware is not manufactured in China.

                  Since then, you have referred to "recent-vintage Pyrex being made in China" in a couple of different threads:
                  and others have again responded that Pyrex glassware is not, in fact, made in China.

                  There is a lot of bad stuff coming out of China (alongside a lot of high quality products). And I'm no fan of exploding glass in my kitchen. But the link between China and exploding Pyrex is an Internet rumor and it would be helpful to stop spreading this misinformation.

                2. Had it happen about 2 years ago and that was the last time it went in my oven.

                  2 Replies
                  1. re: Dax

                    Well of course. Why would anyone put a heap of broken glass in their oven?

                    1. re: GH1618

                      Touche. The other two no longer go in the oven.

                  2. By the way, the original post seems to suggest that the instructions were not followed somewhere. The Alton Brown recipe does not call for "baking," it calls for "roasting":


                    Roasting is cooking with a high, dry heat. But a Pyrex® baking dish is not a roasting pan. The safety instructions call for covering the bottom with liquid if food suspended above it can release moisture which drips into the dish.


                    The risk of breakage when roasting something over a dry Pyrex® baking dish is pretty obvious, I think.

                    1 Reply
                    1. re: GH1618

                      I agree with you, GH. Dripping from a rack onto hot Pyrex is a risky scenario. Some of the Pyrex-shattering stories I've seen can't be attributed to thermal shock, but this one seems explainable.

                      As far as that second link of yours is concerned... "Sandra Lee Shares Simple Rules for Cooking With Care" ... lol!

                    2. Here is a nice video (awesome if I may say) about the extreme thermal shock on tempered glassware. Scroll down and enjoy.


                      1. We recently had a pyrex dish explode in the microwave.

                        1. I have not had Pyrex shatter but I have had two that broke into big pieces while baking for seemingly no reason. Both pieces were 10-15 years old, one a 9 x 13 and the other was a pie dish.

                          1. I had one catch fire in a convection oven. A few Thanksgivings ago, after stuffing the turkey my wife lined a pyrex bowl with foil and put the remaining stuffing in the foil, closed it up and put it into a convection oven. I do not recall how we noticed we had a problem. The glass on the upper edge of the bowl actually caught fire - I saw the flame. We removed it from the oven and placed it on the counter. There may / must have been a wet spot because a few moments later it exploded. Not a fun time.

                            1. Haven't had a problem with mine, and will continue to use it. I have vintage Pyrex from Mom, and recently purchased thrift store treasures. I love it for my pumpkin pies.

                              10 Replies
                              1. re: BIGGUNDOCTOR

                                I too have loved Pyrex pie plates. Every so often I see one of those old pans with the high fluted sides, and I remember baking in those when I was very young. I still think they work well for general purpose microwave cooking. I am dismayed to hear that they might break or explode in the micro. I often put a pie plate in with veggies, covered lightly with clear wrap to steam. And I put my glass measure in the micro often as well. Phooey.

                                I still say, even if the events are explainable, why use something that has to be treated so carefully or else it might break or explode without warning?

                                1. re: sueatmo

                                  sueatmo wrote: "I still say, even if the events are explainable, why use something that has to be treated so carefully or else it might break or explode without warning?"

                                  I use my Pyrex because I'm cheap and don't want to replace it! I think probably 90% of incidents are because of thermal shock (which I can avoid through well-established habits), but 10% seem to be unrelated. So I don't plan to buy more Pyrex. But I'll keep using my existing pieces. (FWIW, I've never had a problem with mine in 30 years.)

                                  1. re: drongo

                                    Nor had I until the pie plate broke.( I have never had an explosion.) I'd been using the stuff for decades.

                                    I actually stopped using the long rectangular Pyrex pans before I knew about the explosions. I hate the way they hog table space, so I bought some deeper, smaller bakers. And I've bought a couple of metal pie pans to replace my old glass pie plates. I'm going to be frank here--my pumpkin pie tasted as I remember it after changing to metal.

                                  2. re: sueatmo

                                    <why use something that has to be treated so carefully or else it might break or explode without warning>

                                    Fair point. I have a pyrex pie plate. I think the argument is that Pyrex produces better baked goods. I am not say that it is true. I am saying that this can be an explanation.

                                    1. re: Chemicalkinetics

                                      It is possible that Pyrex produces a better baked product. Or it may be that people think that Pyrex produces a better baked product.

                                        1. re: Chemicalkinetics

                                          I did a report on glass years ago, and one thing I found was that glass loses up to 80% of its strength when scratched, or chipped. I would attribute exploding Pyrex to damaged items that were exposed to therma shock. My Mom never had a piece explode, I haven't,and I personally do not know anyone who has either. How many pieces of Pyrex bakingware have been sold over the decades? I would say several million. I figure my odds are very good that I will not have a problem as long as it is kept in good shape, and I do not subject it to thermal shock.

                                          1. re: BIGGUNDOCTOR

                                            I am in the middle on this issue, and respect the opinions from both camps.

                                            I agree with you and others that the chance of a pyrex glass (tempered lime soda) is very low, and the reports we have read about constitute a very small fraction of a percentage. So I have no problem using a glassware. That being said, I also understand that it can and has happened -- however small the chance may be. So it is really up to individuals to decide. For a metal (say aluminum) bakeware, it has no chance to shatter and explode, simply because it is what it is.

                                            Now, one may wonder why do scientists use glassware all the time. Glassware is often the prefer vessel because glass is very inert. So if I want to run a chemical reaction between reagent A plus reagent B. I don't want to worry about my vessel reacting with A or B. On top of that glassware are very easy to clean (I mean really really clean). Being transparent is also great.

                                            1. re: Chemicalkinetics

                                              Pyrex bakeware also shatters in a similar way when dropped on a solid concrete floor, as I found out (as if I didn't know!) recently. I bought the glass lid for my cast iron pan in a hardware store about 20 years ago. In the meantime, it's become a vintage item instead of a commodity. I'm buying another, though. The possibility of breakage is more than offset by the advantages of glassware.

                                              1. re: GH1618

                                                I like glass lids too. Not all of them go into the oven, but I suppose a Pyrex would. I also agree that this choice is up to the individual. My choice, given that I had a pie plate break, is to use other products for baking.

                                                The thing is, so many have not heard of this issue. At the very least, I'd ditch etched or damaged Pyrex ware for the oven.

                                2. It's not just Pyrex that this happens to. I took a French Picardie glass off the dish rack and it shattered in my hand. I was finding glass shards in the kitchen for two (2) years. I took them back to Williams Sonoma and they exchanged them for me. The glasses, like Pyrex, are very sturdy and hold up to a lot of stress but suddenly, when the stress builds up, the object shatters.

                                  1. Yes. it will happen. I have had 2 glass bakeware pans explode in the oven.

                                    1. I just had my Pyrex baking dish crack for no reason while I was washing it. I've had it for about 10 years now. I'm glad I came across this while I was searching for a replacement.