Pyrex

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For the programming language, see Pyrex (programming language).

Pyrex is a brand name for heat-resistant glass introduced by Corning Glass Works in 1915.

Pyrex was originally borosilicate glass. Though borosilicates had been produced before, the name Pyrex is widely used as a genericised trademark for the material. Corning spun off its kitchenware division in 1998 as World Kitchen, Inc. However, Corning retained the Pyrex brand name, licensing it to World Kitchen and other companies that produce Pyrex-branded cookware.

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.^[1]

1 Safety issues
2 Famous examples of usage
3 References
4 See also
5 External links

[edit] Safety issues

Recent reports suggest that due to the change in manufacturing,^[1] notwithstanding the claims made for Pyrex, the glassware can shatter violently and unexpectedly, even when used in accordance with manufacturers instructions.^[2] Claims have been made of severe personal injury during these events. The tendency to break into large pieces, rather than shatter like normal glass, can produce large cutting edges capable of causing serious injury. 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.

[edit] Famous examples of usage

Caltech's famous 200-inch telescope mirror at Mount Palomar Observatory was cast by Corning during 1934 – 1936 out of Pyrex, which expands and contracts less than ordinary glass. Modern, commercially built reflector telescopes use Pyrex glass for the primary and secondary mirrors.