Talk:Pyrex

There is currently a controversy in Jewish circles about the sanctity of using Pyrex instead of glass for the preparation of kosher food. Can someone please explain why that is? Is Pyrex actually more obsorbant than glass and could possibly "spiritually contaminate" foods, or is it simply because Pyrex was just never mentioned in the old Jewish laws? Kent Wang 06:52, 18 Feb 2004 (UTC)

No, pyrex is not abosrbant at all... Borosilicate is used for scientific apparatus becuase of its strength an non reactionary to anything... Indolering 7 Aug 2005

The question isn't whether Pyrex is kosher or not, but whether it's pareve, meaning it can be used for both dairy and meat. Most surfaces (e,g. metal, porcelain, etc.) are said to absorb the taste of the food cooked in it, and therefore can only be used for one or the other; glass traditionally is exempt from this requirement. For whatever reason, Pyrex is not considered so exempt. I do not know the reason. I have the feeling, though, that it's not the Pyrex per se that renders the cookware not Pareve, but the fact that it's used for cooking (heat exposure increases absorption of taste). As regular glass isn't suited for cooking in, the question never arose. (Disclaimer: I am not a rabbi and this is not a psak.) Shalom S. 14:02, 31 July 2007 (UTC)

Sephardic Jews follow the ruling of the Shulchan Aruch which states that glass is non-absorbent. According to this, a glass utensil can never become non-kosher. Similarly, it can never be considered "dairy" or "meat," meaning that you can use it alternately for both milk and meat, cleaning it out well between use. Pyrex is glass that is reinforced with other materials. This raises the question: Does Pyrex have the same halachic status as glass or not? While there is a dispute about this matter, Rabbi Ovadia Yosef, shlita, rules that Pyrex has the same status as glass. Most sephardic Jews follow this ruling.^[1]Halachic Hammer (talk) 12:47, 4 April 2014 (UTC)

Even though this is old, I want to correct a mistake here: "Pyrex is glass that is reinforced with other materials" is wrong. Glass is not defined by its composition, but its structure: "The standard definition of a glass (or vitreous solid) is a non-crystalline solid formed by rapid melt quenching." (so says Glass). Different types of glass have different composition, but they are all glass. If you argue that boron makes glass "impure", then quartz glass (containing SiO2 only) is the only "pure" glass and practically all glasses found, including lime-soda glass, which is what practically all glass items are made of, are impure. Calling borosilicate glass "glass reinforced with other materials" is like calling oakwood "wood reinfored by oak". 2001:7D0:8887:9B00:11D4:6206:1ED6:4187 (talk) 23:04, 13 January 2024 (UTC)

When Rabbi Moshe Heinemann, Rabbinic Administrator of the Star-K hechshur was asked, "Do arcoroc, duralex, pyrex, corelle and crystal have the halachic status of glass?" He responded, "Yes, they do".^[2]Halachic Hammer (talk) 12:47, 4 April 2014 (UTC)

Pyrex is to Borosilicate as Avian is to H2O. It is a brand name for a chemical structure, and Corning is not the only producers of Borosilicate. I'll edit this when my brain isn't so mushy. —Preceding unsigned comment added by Indolering (talk • contribs) 20:41, 9 May 2004

I just visited the article for the first time, and FYI, the discussion of borosilicate and soda-lime glass could do with a brief statement about the relative merits of the two materials. As it is, a casual reader is left puzzled (a) about the difference between the materials and (b) by the article's detailed discussion of borosilicate glass. 128.36.164.147 (talk) 01:10, 23 December 2009 (UTC)

What is the relationship between Uranium Pyrex (apparently used for some commercial applications) and regular Pyrex? Does Uranium Pyrex substitute Uranium for Boron completely, or is it simply a trace additive? What is the historical relationship between the two types of Pyrex? Did early Pyrex kitchen vessels contain trace amounts of uranium, in the same way that early Fiestaware contained uranium? --Chris Thompson 05:10, 16 Nov 2004 (UTC)

They just added Uranium for coloring, like the Fiestaware. Replacing the boron would make it not Borosilicate. There are many, many, many Borosilicate compatible glass with colorants, they are still refered to as borosilicate. Indolering 7 Aug 2005

AFAIK Corning invented Borosilicate... I am checking it out with other blowers. Indolering 7 Aug 2005

Is this really a stub? Shouldn't most of the information on Borosilicate be on Borosilcates page? Other than metioning Pyrex is Borosilicate should anything else be here? Indolering 7 Aug 2005

This article is way too small for such an important contribution to humanity. —Preceding unsigned comment added by 4.234.218.223 (talk • contribs) 11:18, 30 August 2005 (UTC)

But... Pyrex is expansion-resistant! --Liface 02:45, 1 December 2005 (UTC)

(b~_^)b Wonderful! PrometheusX303 17:00, 27 June 2006 (UTC)

I saw a segment about Pyrex on John Ratzenberger's Made in America, here is some more information. —Preceding unsigned comment added by 4.234.218.223 (talk • contribs) 12:15, 31 August 2005 (UTC)

Leave the information about Pyrex catatrophic failures in, please. It is documented problem with Pyrex in particular. —Preceding unsigned comment added by 66.68.97.204 (talk • contribs) 06:48, 8 February 2006

The fact that Pyrex is now "tempered soda-lime glass" means that in it's normal state, at room temperature and pressure, it has enormous "built-in" stress. Consequently, when it fails it fails dramatically. Tempered glass failure can be initiated by even a single microscopic scratch, and normal household cleaning of cookware tends to scratch the surface. Borosilicate Pyrex glass cookware is normally not tempered. —Preceding unsigned comment added by 131.215.115.31 (talk) 20:31, 18 June 2009 (UTC)

Recent reports suggest that, notwithstanding the claims made for Pyrex, the glassware can shatter violently and unexpectedly, even when used in accordance with manufacturers instructions. Claims have been made of severe personal injury during these events. Some reports have suggested that older Pyrex was not as susceptible to these problems as currently produced Pyrex. It is unknown whether this has anything to do with the recent change in ownership and location of manufacture of the Pyrex brand.

I've pulled the above paragraph from the article until appropriate sources can be provided. (Reliable sources are preferred over class action lawyers.) TenOfAllTrades(talk) 02:41, 9 May 2006 (UTC)

It's true 71.132.144.78 22:39, 22 May 2006 (UTC)

Reports of this are gathering all over the place now. See consumeraffairs.com: Consumer complaints about Pyrex Cookware and Reviews on Amazon.com for just two examples, but there are quite a bit more if you search for "pyrex ~explode" on Google. I'd like to see this paragraph put back into the article. -- Heptite (T) (C) (@) 06:53, 20 October 2006 (UTC)

I looked through the history and it looks like the first time this paragraph was added it was completely uncited, so I concluded I could put it back in with the consumeraffairs URL as a reference. -- Heptite (T) (C) (@) 13:37, 22 October 2006 (UTC)

(OR) I've seen a Pyrex dish detonate with extreme force. This was in 1986 or so, too. My own Pyrex casserole dish remains firmly undetonated. Vashti (talk) 11:58, 30 November 2007 (UTC)

A better source is needed, as forums such as the consumer affairs site does not qualify as a reliable source. There has to be a news service someplace that would have picked this up by now. --- Barek (talk • contribs) - 20:39, 14 March 2008 (UTC)

Sounds like YOU work for World Kitchen! This very thing happened to me! I thought - No Way! This shouldn't be possible! - but it did, and its a huge safety risk so STFU! --66.223.168.45 (talk) 01:29, 19 May 2010 (UTC)

Why is this not on the main page? Pyrex shatters. Reports are all over the place. Consumer reports January 2011 issue has the stories. ^[1] I met a elderly woman in an outlet mall who showed me the damage an exploding pyrex dish did to her and decided to look it up. Sure enough, she was telling the truth and yet this was removed from the main page? Just because it didnt happen to someone who has the ability to remove it from the main page doesnt mean it hasnt happened. Please, dont be afraid of the truth people. This needs to be added back to the main page. I will be putting this on my web site and my facebook page. MediaPlex (talk) 17:17, 17 August 2011 (UTC)

It's in the October 2011 issue of Consumer Reports, (page 40, title "Shattered Glass"), it has been reported bt ABC news ( http://abcnews.go.com/GMA/ConsumerNews/holiday-cooking-hazards-glass-bakeware-spontaneously-shatter/story?id=12328800 ) and two makers of Pyrex, have addressed the matter (http://abcnews.go.com/GMA/statement-abc-world-kitchen-maker-pyrex/story?id=12328932), (http://abcnews.go.com/GMA/statement-abc-anchor-hocking/story?id=12328935). Write it up, make sure it's properly referenced, and it stays in the article. --Guy Macon (talk) 22:48, 4 September 2011 (UTC)

The statement that the pyrex cookware is not pyrex is unsupported. The only mention in the "reference" was a line that world kitchen product is soda-lime. This was an legal filing. Lawyers are not accurate sources for technical information. The world kitchen website clearly states that their glass is the same product as pyrex made in the past. The line about how to use pyrex cookware is no support to the notion that pyrex is not pyrex as labware made from borosilicates is subject to similar restrictions except where physical form allows such uses subject to physical inspection and limited lifetime. —Preceding unsigned comment added by 204.255.236.127 (talk • contribs) 12:56, 30 July 2006

Re this statement, I think looking at the sequence of 10-Ks filed is illuminating:

The annual report for 1999 states that Pyrex-Registered Trademark- products are made of borosilicate and tempered soda lime glass and are available in a number of colors, shapes and sizes.

The annual report for 2001 states that Pyrex products are made of tempered soda lime glass and are available in a number of colors, shapes and sizes for a variety of cooking functions.

Finally, the annual report for 2003 states that Pyrex(R) glass products are made of soda lime glass and are available in a number of sizes, shapes and colors for a variety of cooking and storage functions.

The World Kitchen website explains that Pyrex is an old, well-known brand name (which it is), but I see no statement about the current composition of Pyrex cookware. Obviously, given that the cookware is no longer borosilicate glass, WKI has no reason to say so, and one would expect them to evade the point. What I see on the website seems consistent with this. Spacepotato 21:59, 30 July 2006 (UTC)

According to World Kitchen, at least some Pyrex kitchen bakeware produced in the Charleroi, PA facility is tempered soda-lime glass and, indeed, at least some always has been. My impression is that only the lab glassware is and always has been borosilicate glass. My suggestion would be to write World Kitchen customer care and ask; I did. Here's what they said:

We have received your recent email, and would like to correct some

misconceptions about PYREX(r) glass bakeware. PYREX glass bakeware has been made of a soda lime composition in Charleroi, PA since the 1940's, including during the time before 1998 that the Charleroi, PA facility was owned by Corning Incorporated. The product is thermally strengthened to permit it to be used safely in accordance with its safety & usage instructions, and continues to be produced with the high degree of quality and integrity as always. PYREX is a registered trademark of Corning Incorporated used under license by World Kitchen, LLC.

Sincerely,

Misty

World Kitchen Consumer Care Center

So there you have it. Clear as mud, eh? —Preceding unsigned comment added by 68.53.90.215 (talk) 02:30, 11 June 2008 (UTC)

I think the last entry (which was quickly reverted, not surprisingly) regarding the use of Pyrex to make sexual aids is perfectly legitimate. For one thing, the dildo article itself also makes note of the use of Pyrex. Don't let your delicate sensibilities get the best of you, sexual aids are a huge industry, and the use of Pyrex is quite significant given its durability, ease of cleaning and inherent hypoallergenic nature. If the article can make note of the use of Pyrex for marijuana pipes and guitar slides, then its use in making dildos is perfectly acceptable and noteworthy. I am putting the entry back in the article. Chris 12:47, 10 August 2006 (UTC)

I agree. Good call. PrometheusX303 12:55, 10 August 2006 (UTC)

Aye. If they're actually used for that, which apparantly they are, then I don't see why it shouldn't be added.Gorovich 17:15, 17 August 2006 (UTC)

A poorly inserted sentence in the intro to this page made me look for information about ARC International owning the PYREX brand, which led me to http://www.arc-international-cookware.com/en_Home.html which seems to indicate that they do indeed own it. The FAQ about their ovenware at http://www.arc-international-cookware.com/en_Glass_Ovenware.html says they make it out of Borosilicate (they use the brand PYREX for things other than borosilicate cookware though). ChaosNil 05:25, 18 January 2007 (UTC)

It may be that they just have a license to market borosilicate and other cookware under the pyrex brandname (see the history sidebar on http://www.answers.com/topic/arc-international). ChaosNil 05:42, 18 January 2007 (UTC)

According to the website's legal section (http://www.arc-international-cookware.com/en_Legal_information.html), "Pyrex is a trademark of Corning Incorporated licensed by Arc International Cookware SAS, used by permission." I'm no lawyer, but that sounds like Arc doesn't own Pyrex (Trademark) or Corning (Company). Endasil 21:59, 23 January 2007 (EST)

If you look on the World Kitchen site, it also states that the name is licensed from Corning. Presumably, even though they didn't want to hang on the the company, Corning felt the Pyrex name was too valuable and retained ownership of it. I made a note in the article to reflect this. KarlM 20:17, 28 January 2007 (UTC)

I think the article is too USA-centric and is potentially misleading. I did some work for Newell in the 1990s when they owned Pyrex (bought from Corning). Pyrex are expunged from their history on the web site. Their manufacturing plant is in Sunderland UK. It looks like they sold out to a competitor, Arc who are French, but just about every UK school kid would recognise their school-issue water classes, not sure when. I would assume that either Pyrex is still being manufactured at the Sunderland plant (they also had a plastics plant near Frankfurt) or Arc are manufacturing it. They historically used similar glass. Arc still state that their Pyrex is Borosilicate

Spenny 13:26, 21 June 2007 (UTC)

Seeing as "Pyrex isn't pyrex" now apparently (heh) it would appear to make sense to move the general chemistry info to the generic article and make this more about the brand. Chris Cunningham 12:00, 16 February 2007 (UTC)

Done. Chris Cunningham 10:51, 14 March 2007 (UTC)

There seems to be a contradiction in the article, where the first sentence initially states that "Pyrex is a brand name for heat-resistant glass introduced by Corning Glass Works in 1915.". However, further down the article, we see the following statement: "Pyrex kitchen products produced by World Kitchen are no longer made from borosilicate glass, but from soda-lime glass. Their packaging indicates that they must never be used over a flame, on stove tops, under a broiler, or in a toaster oven.". This seems to contradict the first statement. Additionally, in my chemistry class at school we often use Pyrex brand glass (It has the name on it, of course...) kitchenware over a bunsen burner, and never has one of the piece cracked or broken yet. (Unlike the non-Pyrex kitchenware, which cracks as soon as you put it in the flame - even our science equipment does that, ie. test tubes and boiling tubes.) - Xander T. 01:20, 1 April 2007 (UTC)

"No longer" refers to a 2004 statement. One assumes that your chemistry department is still using Corning Pyrex from before this date. Chris Cunningham 10:30, 1 April 2007 (UTC)

That is not the point I am trying to make. Please read my statement again. Xander T. 05:42, 13 April 2007 (UTC)

I'm not seeing it. "Pyrex is a trademark for heat-resistant glass" is still a true statement. The definition of "heat-resistant" has changed a little with the change in material, but soda-lime glass is still heat-resistant. If I'm missing your point please elaborate. Chris Cunningham 07:38, 13 April 2007 (UTC)

Yes, it does say that, but then it goes on later to say "Their packaging indicates that they must never be used over a flame, on stove tops, under a broiler, or in a toaster oven.". This implies that they are in fact NOT heat resistant, thus contradicting itself. Or, at least, it is not as heat resistant as it used to be. However, heat resistant glasses should not crack when exposed to rapid temperature changes above the normal rate at which plain soda-lime glass breaks - this is not mentioned. Xander T. 10:20, 16 May 2007 (UTC)

The Pyrex *brand name* is now being used on metal bakeware from World Kitchen. It is in World Kitchen's financial best interest (and their obligation to their shareholders) to make the distinction between borosilicate and tempered soda-lime products as wiggly as possible so that they can exploit the brand name to fullest effect. Note that "heat resistant" is pretty ambiguous... Styrene is heat-resistant compared to wax. Watch for Pyrex brand men's briefs in the near future. —Preceding unsigned comment added by 131.215.115.31 (talk) 14:55, 21 April 2011 (UTC)

This is more of an academic question, since I think the picture should stay just because it's informative, but shouldn't this photo be qualified as an editor's own work and thus an invalid entry for the encyclopedia? Especially since, given the context, it takes a side in a two-sided debate. <spetz> —Preceding unsigned comment added by 208.120.85.210 (talk) 20:20, 25 October 2007 (UTC)

For sure. Even the caption "exploded" is misleading. There is a distinction made between "exploding" and "breaking". There is no internal pressure that causes pyrex to break. You might say that it exploded in the same sense as The vase exploded into tiny pieces when it hit the floor. But that's a bit of a stretch. 216.16.228.6 (talk) 16:42, 28 February 2008 (UTC)

Sadly the photo is no longer in the article so we can't see the size and shape of the fragments. Where is the photo ? Does tempered glass usually break into sub-centimetre cubical fragments (like toughened automobile windows) ? My white pyrex plate (Labelled PYREX ENGLAND) shattered into long curved VERY sharp shards. - Rod57 (talk) 18:57, 30 October 2014 (UTC)

In reference (1) in the pyrex article it is stated: "Pyrex(R) glass products are made of soda lime glass and are available in a number of sizes, shapes and colors for a variety of cooking and storage functions." However, I do not believe that the person who wrote this up (what is his/her name actually?) really knows what he is talking about. If bakeware really would be made of soda-lime glass it would shatter quite often during baking or when exposing it to cold air afterwards, and the product would not sell any longer. I would like to propose replacing reference (1) with one in a well reviewed technical book or journal, and correcting the statement in the article accordingly.--Afluegel (talk) 10:07, 26 January 2008 (UTC)

Please email the manufacturer of Pyrex and ask whether their products are made of borosilicate or soda-lime glass. They will tell you that all Pyrex products are made of soda-lime glass. Edit: If this may not be true if chemistry lab equipment is still manufactured under the Pyrex brand name, in which case Pyrex lab equipment is likely still borosilicate. But correspondence with Pyrex confirms that all Pyrex brand kitchen ware is soda-lime.—Preceding unsigned comment added by 70.248.177.202 (talk • contribs) 22:07, 26 January 2008

See Wikipedia:Conflict of interest/Noticeboard, where a company spokesman has expressed his concerns with some of the safety claims in this article. Anyone who has an opinion is welcome to join the COI discussion.

Looking at the article myself, I don't see any reliable sources to back up the Safety Issues paragraph. There is a site called consumeraffairs.com, which apparently publishes complaints sent in by individuals with no further vetting or any attempt to reproduce the described failures. There is also a 10K statement from some company, a legal document that is considered a primary source under our rules, and probably not an adequate source for any negative claims. I believe that the privately-made photograph should also be removed.

If anyone believes that the 'Safety Issues' paragraph should remain in the article, please comment at WP:COIN. Since keeping it in the article could pose legal issues, it has some of the same potential troubles as a violation of Wikipedia:Biography of living persons policy would have, though the target of the negative claim is a company rather than a person. EdJohnston (talk) 16:58, 17 March 2008 (UTC)

Yeah, I agree about the safety section - pending a reliable source, I've removed it. Full link to section is Wikipedia:Conflict of interest/Noticeboard#Pyrex. WLU (talk) 18:36, 17 March 2008 (UTC)

Update: The COIN link has been archived, view archived thread here. --TexasDex ★ 07:36, 24 February 2009 (UTC)

From WP:COIN#Pyrex, possible sources. WLU (talk) 11:18, 20 March 2008 (UTC)

• Safety & Usage Instructions
• STATS.org
• Pyrex, Soda Lime, Borosilicate, and the Environment
• Does Pyrex “Explode” Because the Manufacturer Changed the Mix? CBS Chicago’s Epic Investigation Continues
• Pyrex-O-Mania Continues on CBS Chicago
• CBS Sweeps Week Shocker: Glass Can Break!

soda lime glass can be manufactured as tempered glass, and the pyrex website says as much, so added references to the webpage. I also removed the implication that the change from borosilicate to tempered glass is related to the corporate change. This may be so, but it certainly requires a citation, so I edited the sentence (and others that have words like 'still' that refer to this change in glass composition). The issue of when Pyrex kitchenware changed composition is certainly an interesting one, and deserves further research.Jerry guru (talk) 04:30, 24 May 2008 (UTC)

In this edit, I removed some material added in late December for which the only citation is consumeraffairs.com. See the discussion above at #Pyrex is being discussed at the Wikipedia:Conflict of interest/Noticeboard for the problems with believing this web site. If the claims about Pyrex no longer being tempered glass are true, they are very important and interesting. But they should come from a reliable source, such as a newspaper or magazine. It is not the role of Wikipedia to provide an audience for everyone who has an axe to grind, so we need to satisfy our WP:Verifiability policy. EdJohnston (talk) 04:44, 28 December 2008 (UTC)

• I removed the controversy section - it's actually what Charlie Brooker calls a "nontroversy" - a manufactured controversy whipped up by the media. Pyrex is glass, if you abuse it you can break it. Who knew? Pyrex has been manufactured for nearly a century and is used in extremely demanding applications, including in every chem lab I have ever seen and I would wager that most Western kitchens contain at least one Pyrex or equivalent product, there are literally hundreds of millions of examples of Pyrex ware out there. In that context, "someone broke one once" type scares are well into WP:UNDUE territory. Guy (Help!) 15:51, 28 December 2010 (UTC)

• If it's something in the media, then to call it a nontroversy without a source is POV. It's true that chem lab glass is made under the label of Pyrex, but even if the article didn't already tell you that it was made out of completely different materials, I would still assume that there's no connection between the quality of materials made for chem labs and for home kitchens, any more then the mainframes IBM sells are related to the PCs they sell. Whether we mention it should have to do with the notability of the campaign, not whether or not we agree with it.--Prosfilaes (talk) 06:34, 5 January 2011 (UTC)

This "controversy" requires determined abuse of a product which is in widespread use without meaningful incidence in the wild. See http://www.snopes.com/food/warnings/pyrex.asp Guy (Help!) 13:10, 7 January 2011 (UTC)

The controversy is that they changed it to an inferior material and under circumstances where the previous material, for which Pyrex is known, would know usually break, it may not need to be called "controversy" but removing with POV statements like "Oh glass can break" is absolutely not grounds for removal. Revrant (talk) 21:17, 7 January 2011 (UTC)

There's nothing determined about most of these incidents, and many of the people had followed the instructions that came with their glassware. And you're misstating WP:UNDUE. It says nothing about "someone broke one once"; it talks about "If a viewpoint is held by a significant minority, then it should be easy to name prominent adherents". I think Consumer Reports is a prominent adherent, and Jan Schakowsky and Dick Durbin are not completely unnotable, and the Snopes page you linked is further evidence that this is not an opinion "held by an extremely small (or vastly limited) minority".--Prosfilaes (talk) 21:46, 7 January 2011 (UTC)

The composition changed in the 1940s because tempered soda lime glass is significantly more resistant to breakage when dropped. Virtually all glass bakeware sold in the US is made of tempered soda lime glass for exactly this reason. Pyrex is using exactly the same type of glass as its competitors.

• Exploding the "exploding Pyrex" myth, stats.org
• Have you heard rumors about Pyrex® Glassware breaking?, Pyrex
• manufacturing history, Pyrex
• Exploding Pyrex, Snopes, was at one point on Top 25 urban legends

CPSC considers the product safe. The experts CBS talked to also consider the product safe. Their only comment was that the safety instructions could be clearer.

CPSC records under 300 ER visits due to glass bakeware injuries between 1998 and 2007. In this period Pyrex alone sold over 300 million domestic glass bakeware products, and the CPSC data does not distinguish between injuries due to thermal shock failure and those due to dropping.

As the testers acknowledge, the test of heating to 450 degrees and then placing on a cold surface with water to ensure good thermal conductivity is abuse, not normal use, and is in direct contravention of the safety instructions supplied with the product.

The emails circulated about the "conroversy" claim that World Kitchen is not a US company, and make reference to China. This is false. World Kitchen is part of WKI group, headquartered in Rosemont, IL.

In other words, what we have here is a bog standard conspiracy theory based on the idea that evil squirrels changed to a less safe composition when the Corning sold the manufacturing plant to the Chinese. The truth is that the composition changed over sixty years ago, the same type of glass is used by all US glass bakeware manufacturers, the change was made as a tradeoff between an unlikely failure mode (abuse due to thermal shock) and the most likely failure mode (dropping, which is the dominant cause of glass bakeware breakage, and which the tempered soda lime glass is substantially more able to resist), and the product was and still is made in the US by a US company.

I don't think a sixty-year-old change to make the product more resistant to breakage when dropped constitutes a "controversy" in the usual sense of the word. Neither doe Snopes or stats.org. Guy (Help!) 13:18, 8 January 2011 (UTC)

Do you have any source on it being that old? I'm quite certain it was not soda lime glass that my grandmother has, the other sources point to the change being far more recent. Hang on, are you stating that cooking something for 80 minutes at 450 degrees and then placing it on a wet countertop is abuse? I must admit that I do not follow your logic in that regard, sir, please elaborate further. Revrant (talk) 19:56, 8 January 2011 (UTC)

The changeover to soda-lime glass may have started in the 1940s, but according to a quote at snopes.com and Consumer Reports, some consumer Pyrex was made out of borosilicate glass as late as 1998. Also, if you examine the 10-K filings for WKI Holding Co., Inc., you will see that the 1999 filing says that Pyrex-Registered Trademark- products are made of borosilicate and tempered soda lime glass and are available in a number of colors, shapes and sizes, but by 2001 the word borosilicate was absent. So, the complete disappearance of borosilicate glass from consumer Pyrex may be quite recent. Spacepotato (talk) 00:21, 9 January 2011 (UTC)

No, I'm not saying that placing Pyrex at 450 degrees on a cold wet countertop is abuse, that is stated by the person that conducted the test. The report freely acknowledges that this was done in the knowledge that it was likely to break the product and was against the safety instructions supplied with the product. The fact that you can break glass bakeware through thermal shock is not a secret, never has been. You can do it with borosilicate glass as well. You can also break it by dropping it, which is how glass bakeware usually meets its end. Neither of these is unique to either the manufacturer or the type of glass. Guy (Help!) 14:03, 9 January 2011 (UTC)

Guy, a Wikipedia talk page is not for discussion about the product. It's for discussion of the encyclopedia page according to the rules of Wikipedia: WP:RS and WP:NPOV. All you're doing is giving your opinion of the truth; but that's not how Wikipedia works. "If a viewpoint is held by a significant minority, then it should be easy to name prominent adherents". Stop arguing that the "controversy" is absurd; please start arguing that it's not notable.--Prosfilaes (talk) 03:08, 9 January 2011 (UTC)

It's not my version of the truth, it's the version from the company backed by independent sources such as stats.com. What is indisputably true is that Pyrex has been using tempered soda lime glass for over half a century, that every other manufacturer of domestic glass bakeware also uses tempered soda lime glass, that tempered soda lime glass is much less vulnerable to breakage when dropped, that breakage from dropping is the major source of breakage of domestic glass bakeware, and that this glass is apparently specific to the US market. This is now in the article, as it's factual and well sourced. The obvious inference is that the use of tempered soda lime glass is a response to the US tendency to sue people if glass breaks when it's dropped, but there's no way I'd put that kind of synthetic argument in an article. As to what proportion of their products were made of noe or other type of glass for what proportion of the company's history, we have no proper sources for that. All we can say is that use started in the 1940s and is now universal in the domestic products, as it is for all manufacturers of glass bakeware. There is no evidence that CPSC considers the product dangerous, and there is no evidence that the change was to reduce manufacturing costs (they still make the product from borosilicate glass in the EU, which is no less price sensitive than the US). If anyone can find reliable sources for the rationale I'd be most interested to see them.

We also don't know to what extent the consumer bakeware was made of borosilicate glass in 1998, when the consumer division was divested. We do know that laboratory glassware is still made of borosilicate glass. It may be that the difference is primarily down to the laboratory and consumer divisions being separated. I don't know, the sources don't say.

You will note that I have integrated treatment of the material used into the body of the article, which is as it should be. We know that "controversy" or "criticism" sections are less desirable than discussing things in context (which is why we have the {{Criticism section}} template, apart from anything else). It is pretty clear to me that the way the article was previously laid out was designed to lead the reader to a certain conclusion, one whihc is not supported by independent review of the facts. There is a world of difference between "The company was taken over by the Cinese in 1998, the glass changed to something cheaper to make, it explodes" and "The glass changed to one that is more mechanically robust and cheaper to make, over a period of 60 years, all competitors also use the same glass, it can be made to break with determined abuse but is less likely to break when dropped". There's nothing wrong with noting the fact of the "exploding Pyrex" myth, as it's obviously a notable myth, but a myth is what it is. Guy (Help!) 14:00, 9 January 2011 (UTC)

There are videos of them exploding the material, it is not a myth, in the course of using bakeware what it is used for the most is, well, baking, and to call placing a hot piece of bakeware on a wet countertop "abuse" seems utterly ridiculous. Suggesting that it has been improved is also ridiculous, this is entirely your opinion as both have apparent pros and cons, the article reads better now but this information should be shunned simply because you don't like it, and I can hardly call stats.com a reliable source. Revrant (talk) 02:24, 12 January 2011 (UTC)

There is absolutely no credible evidence to suggest that Pyrex is more likely to break than any other brand, and absolutely no credible evidence that the material was changed for any reason other than that stated by the company, and no evidence at all that it is considered by the relevant professional community to be an unusual source of risk. Guy (Help!) 16:33, 21 January 2011 (UTC)

So a organization that has existed for 70 years to report on consumer issues is not relevant at all.--Prosfilaes (talk) 19:42, 21 January 2011 (UTC)

Uninvolved editor here. I came across this article when I was trying to replace an old Pyrex D-handle measuring cup that I dropped on the kitchen floor. No ax to grind, although I have fond memories of using Pyrex labware in my science classes.

Consumer Reports is undeniably a WP:RS. Their article reports a few rare but sometimes very harmful incidents of exploding heat-resistant glass, from Pyrex and others. In some incidents, they were using the cookware improperly, but in some incidents they were following instructions. Nothing in the Snopes or other cited sources (which should also be cited) contradicts the Consumer Reports article.

There are many arguments here, but the only relevant one is: What is the Wikipedia procedure for dealing with controversial claims like this?

I think the answer is clearly to include an accurate summary of the Consumer Reports article, with any WP:RS rebuttal that any editors think is important, including the company's statements.

WP:NPOV requires us to give all sides of a controversy that is supported by WP:RS, and this is. Consumer Reports, and a congressman, give enough weight to the issue to justify its inclusion.

Furthermore, WP:CONSENSUS doesn't require unanimous agreement, and doesn't allow a single editor to veto the inclusion of a section in an article. If it did, then one employee or fan of a company could eliminate all criticism of that company.

Furthermore, as the talk page says in the header, "This is not a forum for general discussion of the article's subject." Guy's argument above doesn't address the only important issue, which is whether Consumer Reports is a WP:RS and whether the exploding glass is important enough under WP:WEIGHT to belong in the article. Prosfilaes has argued that they do, and his argument is unrebutted.

Whether Consumer Reports' tests were done correctly, whether the consumers were using the glassware properly, whether the change in formula makes a difference, are all questions that we don't resolve in the talk page, although we can address them in the article with WP:RS.

I would point out that if anyone here were working for World Kitchen, and they were removing references to the Consumer Reports article, the next time somebody sues them for injuries, their lawyer would use this Wikipedia article as evidence that World Kitchen tried to hide the dangers from consumers. They will send a subpoena to World Kitchen as part of their usual discovery demanding the names of all employees, contractors, agents, or anyone else under World Kitchen's control or knowledge who may have edited Wikipedia articles about World Kitchen products.

So these deletions (if you'll excuse the expression) would blow up in your face. --Nbauman (talk) 14:53, 22 March 2011 (UTC)

I just created the entry for Reagent bottle. If you have more useful and knowledgeable information, please do add it. Radical Mallard (talk) 16:56, 6 July 2010 (UTC)

The article doesn't really explain why Corning started using soda-lime glass in the US and not elsewhere. The explanation for the US adoption is said to be greater resistance to accidental breakage, but any such advantage would seem to be very marginal to me. Presumably either borosilicate or soda-lime is best for bakeware overall. If so, why isn't one or the other used universally? --Ef80 (talk) 12:30, 21 June 2011 (UTC)

Thats because it was wrong - see discussion here http://www.metafilter.com/98412/American-Pyrex-Less-Resistant-to-Thermal-Shock#3415910 Paraphrased (talk) 11:19, 22 July 2011 (UTC)

That's an interesting link, but even if it's completely correct (it's only a forum after all) the WP article still doesn't cover this borosilicate / soda lime split well, even in a US context. It seems to have been bogged down by 'exploding Pyrex' stories which I hadn't heard of before coming here (I don't think this has ever been an issue in the UK). We need an expert editor to sort this out. I'm neither an expert nor a collector, and have never had glass bakeware of any type shatter through heat stress. --Ef80 (talk) 12:17, 5 August 2011 (UTC)

In the "Consumer Uses" section there are two links to a shopping website I won't even name, since that will only drive up his search ranking. Do I even need to ask permission to erase the links when I see something like this? Company has generic name- Chronicles is part of it-- this site is a shopping cart augmented with a bunch of stolen editorial content. If you erase the shopping cart links feel free to erase this comment. If I don't see it I will know I should have just zapped the camouflaged advertisement the minute I saw it. Paul Rako (talk) 01:20, 24 June 2011 (UTC)

I just removed the entire section as unsourced trivia. In the future, I wouldn't worry too much about removing that sort of thing, it's pretty much just advertising. WLU (t) (c) Wikipedia's rules:^simple/_complex 00:51, 28 June 2011 (UTC)

It's confusing to see the compositions of the two different types of pyrex given in different ways. One lists the elements with oxygen given separately, the other gives a list of oxides making it impossible to compare them directly. Could someone 'normalise' the data and make them comparable? I could have a go, but I fear introducing a mistake because of my rusty chemistry... Stub Mandrel (talk) 17:38, 7 November 2014 (UTC)

The sentence, " World Kitchen documents show that its—and Corning's, since the 1940s—Pyrex kitchenware has been made with tempered soda-lime glass all along, although Corning's imported Pyrex kitchenware was, indeed, made with borosilicate glass." borders on unintelligible and is confusing at best. It should be revised. Grammatically it's a bit of a run-on mixed with a comma-splice? Separating the concepts in the statement out into separate sentences would go a long ways to improve its readability. For instance, the bit referring to "Corning imported Pyrex kitchenware" being manufactured of borosilicate and not soda-lime glass does not belong in that sentence. How the sentence is split-up is probably an issue of grammatical style or preference. JameOxford (talk) 06:48, 18 September 2016 (UTC)

At what temperature does Pyrex melt?

User:PaulFini, I accede to your apparent knowledge about Schott 8830 vs 8330 glass, but must point out that the article's Wikipedia reference says otherwise. If the discrepancy is due to a typographic error in the referred source, it should be explained in an auxiliary reference note (see Template:refn). Also, it would be helpful if other additional references could be added, attesting to the correct numbering. Reify-tech (talk) 16:25, 8 April 2016 (UTC)

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Here is the database of reports to the Consumer Products Safety Commission for Pyrex.

http://www.saferproducts.gov/Search/Result.aspx?dm=0&q=pyrex&srt=0

It's not a WP:RS but it might address some claims made in the Talk page.

It has 407 results. They do explode. There were some injuries, some minor, some leading to emergency room treatment.

For example:

http://www.saferproducts.gov/ViewIncident/1606829

I prepared stuffed peppers and put them in the baking dish. I used the " America's Test Kitchen Healthy Family Cookbook" recipe. I placed the prepared dish into a preheated 350 degree oven for 30 minutes. As I put my hand on the oven door to remove the peppers I heard a loud BOOM. I looked through the window on the oven door and saw glass & stuffed peppers all over. It took FIVE HOURS to clean this mess.

--Nbauman (talk) 04:56, 16 December 2016 (UTC)

As per the edit made by KTC and per the source they and I presumably heard about it from (this video here), the Pyrex company source used on the statement Both trademarks, PYREX (all uppercase) and pyrex (all lowercase, introduced in 1975), were used interchangeably in the marketing of kitchenware products made of both borosilicate and soda lime glass fails verification. Does anyone have an alternative reliable source to back up this claim or should the statement be removed? Silverseren^C 17:58, 21 July 2023 (UTC)

Pinging @Jtfolden since I believe they added the material. Closhund (talk) 04:14, 22 July 2023 (UTC)

For what it's worth, I would agree with removing that sentence until a source can be found. The user who added it isn't very active. Though I would be surprised if the pyrex/PYREX branding were an accurate determiner of glass-type, I've never heard evidence to the contrary, and I can't find a source for it. Closhund (talk) 03:50, 27 July 2023 (UTC)

I would be surprised as well, but especially because of the recent prominence and discussion of the claim, it really needs to be properly sourced before we're stating it here as fact. So I've gone ahead and removed it for now. Silverseren^C 04:04, 27 July 2023 (UTC)

I don't have a reference off hand but I will look. In the meantime, here's some info that may help if someone wants to go digging before I do or has an idea how to solve the issue. As noted and sourced in the page: 1) The lowercase logo wasn't introduced until 1975, but... 2) Corning began using their Charleroi, PA plant in the 1930s to produce Pyrex opal ware bowls and bakeware made of tempered soda–lime glass. This is the most common type of Pyrex coveted by collectors and it does indeed use the all uppercase logo even though it's soda lime glass. Jtfolden (talk) 19:10, 29 July 2023 (UTC)

I've added a new edit on this topic. It doesn't suggest the logos were used interchangeably but it does point out that Corning began using Soda-lime glass for Pyrex approx 30 years prior to the all lowercase logo being introduced. Jtfolden (talk) 21:35, 26 August 2023 (UTC)

Hi All @Silver seren @Closhund @Jtfolden

Sorry to revive this two years after the fact, I have just done some digging on this to get to the bottom of it.

In combination with the source for the 1975 introduction, which has already been added to the article (https://cmog.primo.exlibrisgroup.com/discovery/fulldisplay?context=L&vid=01CORNING_INST:01CORNING_INST&search_scope=MyInstitution&tab=ALWAYS_DISPLAY&docid=alma991233953504126), the following sources clear up the situation:

https://libanswers.cmog.org/faq/398431

Which states: "The short answer is that the change from upper to lower case signified a re-branding of the trademark Pyrex®  in the late 1970s but is not a conclusive way to determine, historically, what type of glass formulation the product is made from."

And additionally: "At some point, Corning, Inc. began to experiment with creating transparent ovenware with tempered soda-lime glass. Likely this change began after Corning started producing its popular opalware in the 1940s, which is made from a soda-lime formulation.

Some manufacturing plants switched to tempered soda-lime formulations, while others continued to produce borosilicate Pyrex® products. According to Herb Dann, a designer at Corning, Inc.  from 1961 until the 1990s, by the time the consumer products division sold, Corning had mostly switched to tempered soda lime glass for almost all of its tableware products."

The Smithsonian Magazine also notes the following here (https://www.smithsonianmag.com/innovation/how-pyrex-reinvented-glass-new-age-180955513/)

"Around the '50s, Corning began making Pyrex out of thermally tempered soda-lime glass, which is less expensive to produce, instead of borosilicate glass."

Additionally, the American Ceramic Society here (https://ceramics.org/ceramic-tech-today/hells-kitchen-thermal-stress-and-glass-cookware-that-shatters/), interestingly, writes the following:

"World Kitchens’ Pyrex-labeled cookware is composed of a soda lime silicate glass. (World Kitchen correctly notes that Corning, itself, changed the composition from original Pyrex to a soda lime glass before it got out of the business)."

Archived at Internet archive here: (https://web.archive.org/web/20111026114654/http://www.pyrexware.com/index.asp?pageId=30), where they claim "Corning Incorporated began making Pyrex glass bakeware from borosilicate glass in 1915 and in the 1940s began making Pyrex glass bakeware from soda lime."

Also, Corning also notes World Kitchen were known as Borden at the time. (https://www.corning.com/au/en/products/life-sciences/resources/stories/in-the-field/pyrex-vs-pyrex-whats-the-difference.html)

So, combining all these tidbits, we can confidently say from sometime in the 1940s/50s Corning gradually phased out their US Pyrex from borosilicate to soda-lime by the time World Kitchen (Borden) took over, and from 1998 all US Pyrex was soda-lime.

This leaves a roughly 20-year window from 1975 to 1998 where lowercase Pyrex could have been produced with borosilicate glass.

Complicating things further, this ad from 1983 shows the uppercase logo on the measuring cups while the graphic on the ad itself has switched to lowercase. (https://web.archive.org/web/20160923011527/http://pyrex.cmog.org/content/pyrex-80s)

Also, another interesting thing I found was that production in France started in 1922, and the factory was relocated in 1970 to Châteauroux which is still in use today. (https://pyrex.co.uk/pages/history)

Hope this is helpful for the article :) I am having issues at the moment using https://iabot.wmcloud.org/index.php?page=runbotsingle and cannot add archives to links; I have raised it as an issue. If anyone else can give it a try on these important links, it would be appreciated. DiamondIIIXX (talk) 07:32, 28 September 2025 (UTC)

@Silver seren Wondering if you saw my info here, do you think it can be incorporated into the article? DiamondIIIXX (talk) 00:20, 8 November 2025 (UTC)

I did miss your response, yeah. That all sounds like you've got ever possible angle of the question covered with those sources, so feel free to add in however you think we should word this to be as clear as possible on the confusing issue. Silverseren^C 00:44, 8 November 2025 (UTC)

@Silver seren @Closhund I've added some new information to the article, trying to synthesise the info I found above. I'm not totally happy with it due to the fragmented nature of Pyrex production meaning there are multiple subheadings to organise the US Pre 1998, US Post 1998, UK and France production as well as distribution. I'm not really sure where to start to clean it up whilst retaining all the intricate details about the production, stamping and distribution. DiamondIIIXX (talk) 21:11, 20 February 2026 (UTC)

Even so, I think you did a great job, DiamondIIIXX. It still reads better and more clear now than it did before and any improvement is a good change. Silverseren^C 02:44, 21 February 2026 (UTC)

Agreed closhund/talk/ 04:34, 7 March 2026 (UTC)