What is pyrex dish

And borosilicate glass is more expensive to manufacture than tempered or soda-lime glass. So if something, such as a crack or flaw, disrupts the compressed outer layer and reaches the tensile zone, that throws off the balance, and the entire piece crumbles into tiny cube-shaped pieces unlike untreated soda-lime glass, which breaks into shards. Surface damage can result from any rough treatment of glass, such as repeatedly scratching it, dropping it, or banging it against another item in the dishwasher.

This damage can weaken the glass without fully breaking it. If you want to get really nerdy, scientists in fracture mechanics call this kind of damage subcritical crack growth. It sounds counterintuitive, but LaCourse also said that although tempered glass is more durable than untreated soda-lime, it actually scratches more easily because the tempering process makes it less dense. Handling tempered wares or any glassware with care is of the utmost importance. Thermal stress is another factor that can cause glass to break spontaneously.

If one part is expanding or contracting more or less than the other, at the region in between [is] where the stress happens. Manufacturing flaws are imperfections in the glass that develop when the piece is made. These include:. Some publications such as ConsumerAffairs have cited this weakening as one possible reason for spontaneous fracture. To me, what we have to worry about are the flaws in the glass surface.

When it comes to bakeware, most reports of exploding cookware—such as this article by Gizmodo or various local news reports —are largely focused on Pyrex.

This is partly because the brand is so popular in the US, but also partly because its bakeware used to be less prone to breaking from thermal shock. Pyrex pieces used to be made of borosilicate glass , which is more resistant to breakage when subjected to extreme shifts in temperature.

And notably, when it does break, it does so suddenly and somewhat violently, shattering into many small pieces. But the percentage of glass cookware shattering unexpectedly is very small, according to Patty Davis, deputy director of communications and press secretary for the Consumer Product Safety Commission.

To be clear, the reported injuries include glass bakeware from all manufacturers, not specifically Pyrex. According to Davis, the CPSC is unable to release information about specific companies without following a public disclosure process.

Currently, Pyrex is made of soda-lime glass , presumably as a cost-cutting measure, as soda-lime glass is very inexpensive. Also, Pyrex is no longer made by the original manufacturer, and is essentially a brand name, rather than a material.

The Pyrex website makes no mention of a change in materials, and does not specify what type of glass is used in their products. Since Pyrex is no longer made of the same special thermal shock resistant glass, one should take extra care when using it.

Do not place Pyrex on your stove top. Do not change its temperature rapidly, regardless of what the website says. Pyrex, in its current incarnation, should be treated more like any other piece of glass. Last updated: January 30, An oft-cited Consumer Affairs investigation from showed some pretty gnarly accounts of people doing simple things like putting a hot Pyrex pan in the oven only to have it explode in their hands, sending scalding shards of glass into their appendages.

There are photos of the injuries, too, so be careful clicking through to the report. Other companies also make cookware out of soda-lime glass , which would make those pans and cups more susceptible to shattering or cracking as well. Pyrex parent company Corelle Brand—again, this is the company formerly known as World Kitchen—said as much, when we asked about the exploding cookware controversy.

Corelle Brands also confirmed that some of its cookware has been made of soda-lime glass since the s. However, when Consumer Reports conducted an investigation into the issue of shattering cookware in , a Corning spokesperson told the magazine that several of its factories were producing Pyrex out of both borosilicate and soda-lime glass up until Corning licensed the brand to World Kitchen in In an email, the CPSC specified that it has received reports of shattering or exploding in the past seven years.

But still, exploding Pyrex incidents do happen, and they keep happening. Following more reports of exploding and shattering Pyrex containers, Popular Science replicated an explosion incident in , showing in a video how small amounts of stress can lead to dramatic breakage incidents due to thermal shock.

After that study was published, Pyrex parent company World Kitchen sued the publisher of the article as well as its authors in the United States District Court for the Northern District of Illinois. The company claimed that the scientific research made false and disparaging claims about Pyrex cookware—specifically its resistance to thermal breakage—and asked the court to have the paper suppressed.

World Kitchen ultimately lost the lawsuit on all counts. Several Pyrex customers who say they experienced exploding glass incidents themselves filed a class action lawsuit in June alleging that Corelle Brands inadequately warns consumers of the thermal breakage issue and then hides behind warnings and warranties when incidents occur.

The court filing details the arguments at length and also contains some troubling images. In December , Corelle Brands filed a motion to have the case dismissed. When we asked about the class action lawsuit, Corelle Brands said it does not comment on ongoing litigation. Yet, the explosions continue. Around the same time the class action suit was filed, one Gizmodo employee experienced an explosion herself after microwaving some refrigerated black beans in a Pyrex container for a few seconds.

The container exploded, though the glass shards were contained in the microwave. To the best of her knowledge, she followed all of the safety instructions, but the situation does bear resemblance to the defect in Pyrex products others have pointed out. Even slight changes in temperature can cause the glass to shatter or explode, and when that happens, the consequences can be dangerous.

According to many consumers, however, the risks are poorly communicated, and the explosion can be unpredictable and dangerous.

What does seem crystal clear on a scientific level is that borosilicate glass is less prone to thermal shock that soda lime glass. And according to experts, the Pyrex glass can explode into small pieces. Uncommon as these explosions may be, they sound bad. But following the rules it could mean the difference between a delicious cooked casserole in an intact Pyrex pan and an oven full of glass shards and food bits.