I want to know can I use Pyrex glass round casserole as a safe cookware on gas burner?

Does this cookware release toxic chemical in high temp?

I only worried about toxic compounds and not about cracking!

  • 1
    "Does this cookware release toxic chemicals at high temp?" - Only if you substitute "dangerous" for "toxic" and "glass shards" for "chemicals".
    – Marti
    Aug 6, 2013 at 17:01
  • @Marti Are you saying that only danger is glass shards after crack of pyrex?
    – Majid
    Aug 6, 2013 at 18:00
  • I did that once as a kid with a Pyrex measuring cup, it exploded, glass everywhere. Had I been standing right there I really could have been hurt. I imagine that a Pyrex glass round casserole could do the same thing, not toxic, but definitely a safety risk.
    – Jolenealaska
    Sep 26, 2013 at 3:06

2 Answers 2


Update based on edited question: there are no issues of toxicity.

It is a very poor idea to use glass cookware on a burner. Not all Pyrex is made from high quality borosilicate glass anymore, and even if you have some, the issue is thermal shock, not toxicity.

If you heat or cool glass very rapidly, the internal stress caused by thermal expansion (or contraction, when cooling) can cause it to shatter. This can be a real safety issue when it is full of hot food.

For this reason, you generally only want to use glass cookware in the oven, and never transfer it directly from the freezer to the oven, or the oven to the freezer.

  • excuse me; I searched many different cookwares but I don't know which cookware is safest,so I found pyrex. but you say it is not good idea,now you think which should I use instead?
    – Majid
    Aug 6, 2013 at 15:13
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    See: cooking.stackexchange.com/questions/30444/… If your goal is indestructibility and non-toxicity under extreme conditions, I would recommend stainless steel.
    – SAJ14SAJ
    Aug 6, 2013 at 15:18
  • I have some stainless steel set but some of those are heavier than normal ,Is it possible that my set be in low quality and have lead in it? is its high weight normal?
    – Majid
    Aug 6, 2013 at 15:25
  • 1
    Pyrex is a brand which is licensed to only a couple of manufacturers, so the quality should be relatively controlled. On the other hand, if you mean generic glass cookware, well, still, likely not but I cannot guarantee anything. Some manufactuers in some parts of the world are less scrupulous and regulated than elsewhere.
    – SAJ14SAJ
    Aug 6, 2013 at 15:42
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    I have no idea.... nor how to express it even if I did. Looking around a kitchen supply store will give you a pretty good idea.
    – SAJ14SAJ
    Aug 6, 2013 at 15:54

The symbols for that glassware do not indicate stove top use.

I have owned glassware (Corning Ware Visions) that was specifically build for stove top use, the design, glass color and symbols designation were different. The 300 degree centigrade rating would be on the low side for a gas flame (900 - 1500 deg C).

I also have personally had oven-safe cookware fail when using on an electric hob. It crumbled after a while and contents went everywhere, so I definitely wouldn't risk it.

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