Consumer Reports Investigates: Glass bakeware that shatters

[eppur_se_muova]

Just read this article this morning while waiting in the doctor's office. Short version: "Pyrex" made in the USA is no longer borosilicate glass, which has a low coefficient of thermal expansion and is therefore much less prone to break on rapid heating or cooling (lab glassware is mostly borosilicate). Pyrex made in Europe is borosilicate. CR lab tests showed the American products were more likely to shatter due to thermal shock under conditions likely to be encountered in a normal kitchen, and recommended the Consumer Products Safety Commission (CPSC) investigate the issue.

Corning sold its U.S. Pyrex production to World Kitchen in 1998, but may have stopped using borosilicate before that date -- it is not clear, and the companies involved make contradictory statements. Apparently borosilicate (which melts at higher temps) would have required more pollution controls, so mfgrs turned to lower-melting soda-lime glass, the cheapest kind, instead, and use heat-tempering to produce a stronger product, but not one with the same heat resistance as borosilicate.

I foolishly thought that Pyrex^® was an identifier specifically for borosilicate glass; apparently it is just a brand name, and can be applied to whatever its owner wishes.

"The baking dish just exploded as my daughter was about to touch it, sending pieces of glass and hot juices from the ham flying everywhere," says Szczcenia, 63. "We had splash burns on our arms and the tops of our legs, and my 3-year-old granddaughter stepped on a piece of glass before I could get her out of the kitchen. I can't begin to tell you how scary it was."

She filed a report with the Consumer Product Safety Commission and contacted the manufacturer. The company said it is possible that she had not followed the bakeware's instructions and that it could not confirm that the product was Pyrex because she had not sent the shards for the company to examine. Szczcenia says she has no doubt the dish that shattered was Pyrex because she'd just purchased it for her daughter a few weeks earlier, and as a loyal Pyrex customer for 30 years, she always looked for that label.

"I loved my old Pyrex, and I certainly know how to use it properly," she says, "but it seems like the only correct instructions for this new Pyrex would be not to use the dish near heat at all."
***
In recent years, news reports and Internet postings about glass bakeware unexpectedly shattering have some consumers worried about safety and confused about instructions. Packaging may prominently say freezer-safe and oven-safe. But consumers might not be aware of warnings which can appear on the back of a label in type this small with cautions about preheating the oven, cooling, use of liquids in the pan, and more.
***
more: http://www.consumerreports.org/cro/magazine-archive/2011/january/home-garden/glass-cookware/glass-cookware/index.htm

I first became aware of this issue through this posting on DU :thumbsup: (I think there might have been a couple of others at about the same time). Note that this is about Corning Ware^®, not Pyrex^®, but the issue of an inferior product being sold under an established, trusted brand name is the same:
http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=389&topic_id=6741717&mesg_id=6741717

My sister bought a lot of Corning Ware through Craigslist at about the same time, and after comparison with my Mom's cookware, we found that some of the older dishes are marked "for range and microwave" while the very oldest (pre-microwave) are unmarked. Some of the newer pieces in our kitchens are labeled for stovetop use, but not microwave. Others have only the Corning Ware^® mark, and one includes the word "Pyroceram". Probably best not to assume it is microwave- or broiler-safe if it is not clearly marked as such, at least if it is newer.

Here are some posts by DUers who experienced these problems first hand:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=105&topic_id=8518881&mesg_id=8518881

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=105&topic_id=8254081&mesg_id=8254081

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=105&topic_id=5956738&mesg_id=5956738




ETA: a Googlon for other sources/citations ...
http://www.google.com/search?q=consumer+reports+corning+anchor+hocking&rls=com.microsoft:en-us&ie=UTF-8&oe=UTF-8&startIndex=&startPage=1



ETAA: wikis (needing cleanup/citations):
http://en.wikipedia.org/wiki/Borosilicate_glass
http://en.wikipedia.org/wiki/Tempered_glass

[EFerrari]

1. Happened to me over the holidays.

No idea when the dish was made but it had to have been in the 90s.

[MineralMan]

2. I haven't bought any new glass bakeware for a long, long time.

I simply go to Goodwill or another thrift store and buy old pieces of Pyrex and Corning Ware. It's all in very good supply in the thrift store marketplace. Lots cheaper, too. The old stuff is just fine.

[no_hypocrisy]

3. Leave open a tort action in strict products liability.

[Pathwalker]

4. All my Pyrex and Corning Ware is from the 50's, 60's and 70's.

Still going strong. Apparently the old stuff is a hot new collectible. Last fall, I was at an antique store and saw a bunch of it and thought I could pick up a replacement for the one missing bowl in one of my sets. $50 for the second to smallest bowl! Nevermind, I'll do without it.

[eppur_se_muova]

5. Check Craigslist -- my sister got good deals there.

Yes, anything made Before Everything Turned To Crap is collectible now.

[defendandprotect]

7. Don't throw out anything old that still works!! Especially stainless steel pots and pan!!

[Pathwalker]

Yeah, I still use my 60's Revere Ware every day, almost.

Plus, I inherited my all my MIL's kitchen stuff, so I actually have 2 sets of most everything. Except that one bowl - sigh. Will try Craigs list.

[defendandprotect]

12. Lucky you .... I threw away a 12" Revere war original -- wish I had it back!!

Finally had to buy a 10" on E-Bay just to get by -- $35 -- and not an original!

One of the ones made in the later years.

Sigh!

[SoCalDem]

20. I have a 3 piece Pyrex mixing bowl set I am getting rid of

what size are you missing & where are you?

[REP]

17. I have Revere Ware from the 50s and US-made modern All-Clad - both are great

[SoCalDem]

21. I use a "tea-pan" almost ever day that looks like it came over on the Mayflower

It was my mother-in-law's mother's .. It's the heaviest stainless steel I have ever seen:)

[pipi_k]

23. As my Teflon pans wear out, I'm replacing them...

with stainless steel and cast iron.


Cast iron does everything, and it's almost as non-stick as Teflon. Low maintenance, and I don't have to worry about them being scratched.

[Ratty]

6. Just learned about this on America's Test Kitchen

They were reviewing broiler-safe pans and mentioned that once in the test kitchen they happened to put a hot pyrex pan onto the counter where there was a little bit of water and the thing exploded into a million shards. That was an eye opener. I did not know that about pyrex. I went out and got myself the Emile Henry stoneware pan they recommended a few days later.

[eppur_se_muova]

8. A sure sign it was tempered glass, not borosilicate. nt

[Renew Deal]

11. Didn't the old borosilicate shatter too?

It wasn't perfectly safe.

[eppur_se_muova]

14. It would fracture, but not likely "explode". Tempered glass ...

is usually made by rapidly cooling molten glass. The rapid cooling causes the outside to contract rapidly, leaving the glass inside squeezed under pressure. When the glass breaks, the pressure is released, and sends the fragments flying.

http://en.wikipedia.org/wiki/Tempered_glass
http://en.wikipedia.org/wiki/Tempered_glass#Advantages discusses different degrees of heat treatment

Of course, I'm pulling a bit of a Frist here, by making a diagnosis on the basis of a third-hand anecdote. :)

I've worked with borosilicate in the lab for years, never seen a piece "explode", and only "shatter" when dropped. Borosilicate rarely breaks from heat shock, but when it does, it's usually just a large crack -- two pieces is pretty common, not a burst of shards.

[Renew Deal]

10. America's Test Kitchen is great!

I love that show.

[Renew Deal]

9. I've been around shattering Pyrex once or twice.

It was years ago, so it was probably with the original product. I remember my mom doing something with a dish around the oven, and the thing shattered. Another time I think I might have put a hot glass on a cold surface or in cold water and it exploded.

[salvorhardin]

13. I bought a small set of Pyrex baking dishes last year

When they came I was really puzzled and somewhat frightened by the 3 page pamphlet of instructions that made it seem, as Szczcenia noted in the Consumer Reports article, that the only safe use of these dishes was to never heat them.

Then I read a Consumerist blog post on this topic earlier this year and learned that new Pyrex sold in the U.S. is no longer borosilicate. I feel cheated! And every time I use one of these dishes I'm paranoid about it exploding in the oven or when I set it onto the counter to cool.

Oh well, it was only $20 but still... I bought Pyrex because it's associated with quality cookware in my mind. Instead I got ordinary glass.

[udbcrzy2]

15. Glass bakeware is so easy to clean

I had some older pieces, but I lost them when my daughter made foods and gave to her friends. They never returned the dishes and at their own risk...

[Sherman A1]

16. Happened to a co-worker last fall

not only ruined what she was making, but there was the oven clean up and she cut herself doing so.

Just a bad situation all around.

[SoCalDem]

18. Old glass dishes cost a LOT, if you can even find them

Remember the "Visions" series? Vermont Country store sells it, but it costs BIG BUCKS


Originally introduced in 1982, Visions cookware by Corning has been much-requested and hard to come by. Known for its durability, this versatile cookware can go directly from the freezer into the oven, microwave, or onto the stove top. And since every piece is transparent, you can keep an eye on your creations while they cook instead of constantly removing the lid to peek inside. Serve right at the table in these attractive pieces, and then store leftovers in them using the matching plastic lids. Versa Pot set includes a 2½ qt., 1½ qt., and 1 qt. pot with lids, and plastic storage covers. Dishwasher safe.

* Goes straight from freezer into oven, microwave, or stove top
* Transparent, so you can see what you're cooking
* Each piece comes with plastic lids for easy storage
* Versa Pot set includes a 2½ qt., 1½ qt., and 1 qt. pot with lids
* Completely dishwasher safe

Visions cookware by Corning makes cooking, storing, and freezing easy.
Item #:
44111
Price:
$139.95

[csziggy]

22. Thanks for the reminder about Vermont Country Store!

They do carry some Borosilicate glass bakeware and they identify it as such! I may get this one:

2-in-1 Roasters
Borosilicate glass bakeware goes from oven or microwave to table to fridge, and then into the dishwasher. Our 2.8 qt. rectangular roaster (13"x8"x5") has a high top that can be used alone as a deep baking dish. Our large-capacity roaster (8-qt., 16"x10"x6") is ideal for a big family meal. Heat-resistant, nonporous Simax glass does not stain or absorb odors.
Item #: 58743
Price: $39.95

These are tempting, but I don't really need the sizes:
Glass Ovenware
Borosilicate glass bakeware goes from oven or microwave to table to fridge, and then into the dishwasher. We offer it in your choice of a 2.2 qt. oval (12"x8"x2") or a 1.6 qt. square (10"x8"x2", including handles).
Item #: 58485
Price: $26.95


I still have two Vision pots - a 2.5 quart and a 1.5 quart with their lids. They are ancient but they still are terrific. I like the one that has a little pour spout on it - it is the one I use for soup to make it easier to pour into mugs.

[SalviaBlue]

19. This happened to me too.

My pyrex exploded just as I set it down after removing from the oven. I was in shock and afraid to look at my hands. They stung but were not cut. I was lucky.