chemistry

Pyrex

Pyrex is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Pyrex rather than just read about it. In short: Pyrex (trademarked as PYREX and pyrex) is a type of borosilicate glass developed by Corning Incorporated in 1908. Pyrex was first introduced to the public in 1915, as a brand of clear, low-thermal-expansion glassware products, whose resistance to chemicals, electricity, and heat made it ideal for laboratory glassware and kitchenware.

Key takeaways

Pyrex belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pyrex to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pyrex from memory before moving on to harder problems.

Reference excerpt

Pyrex (trademarked as PYREX and pyrex) is a type of borosilicate glass developed by Corning Incorporated in 1908. Pyrex was first introduced to the public in 1915, as a brand of clear, low-thermal-expansion glassware products, whose resistance to chemicals, electricity, and heat made it ideal for laboratory glassware and kitchenware. In the 1930s, Corning expanded the brand to include kitchen products made of soda–lime glass and other materials. In 1998, Corning Incorporated spun off its kitchenware division, including Pyrex cookware. Currently, Pyrex dishes are manufactured by Corelle Brands in the United States and International Cookware in Europe. Corning Incorporated continues to manufacture Pyrex scientific glassware.

History

Corning Glass Works

Borosilicate glass was first made by German chemist and glass technologist Otto Schott, founder of Schott AG in 1893. Eugene Sullivan, director of research at Corning Glass Works, had learned about Schott's borosilicate glass while studying as a doctoral student in Leipzig, Germany. In 1908, Sullivan, along with Corning scientists William Churchill and George Hollister, developed a low-expansion glass, able to withstand dramatic temperature changes, for use in railroad signal lanterns and other industrial products such as battery jars. The called it Nonex - short for "non-expanding".

Following this breakthrough, Corning was seeking additional markets for this glass. Jesse Littleton, another scientist at Corning, discovered the cooking potential of borosilicate glass by giving his wife Bessie Littleton a cut-down Nonex battery jar to test out as a casserole dish after her ceramic one shattered in the oven; it proved very successful. Corning removed the lead from Nonex and developed its first consumer product, a pie plate. Pyrex made its public debut in 1915 during World War I and was positioned as an American-made alternative to the German-made Duran.

The material was initially marketed for pie pans and advertised as "Pie Right" or "Py-Right", but the name was eventually changed to Pyrex to rhyme with Nonex. A Corning executive gave the following account of the etymology of the name "Pyrex":The word PYREX is probably a purely arbitrary word which was devised in 1915 as a trade-mark for products manufactured and sold by Corning Glass Works. While some people have thought that it was made up from the Greek pyr and the Latin rex, we have always taken the position that no graduate of Harvard would be guilty of such a classical hybrid. Actually, we had a number of prior trade-marks ending in the letters ex. One of the first commercial products to be sold under the new mark was a pie plate, and in the interests of euphonism the letter r was inserted between pie and ex and the whole thing condensed to PYREX.Corning purchased the Macbeth-Evans Glass Company in 1936 and their Charleroi, Pennsylvania plant was used to produce Pyrex opal ware bowls and bakeware made of tempered soda–lime glass. In 1958 an internal design department was started by John B. Ward. He redesigned the Pyrex ovenware and Flameware. Over the years, designers such as Penny Sparke, Betty Baugh, Smart Design, TEAMS Design, and others have contributed to the design of the line.

Corelle Brands In 1998 Corning Incorporated divested itself of its consumer products division, which was renamed World Kitchen in 2000, and Corelle Brands in 2018. Corelle took over production of Pyrex and other Corningware products in the United States. In 2019 Corelle Brands merged with Instant Brands, the makers of the Instant Pot. The combined company filed for Chapter 11 bankruptcy in 2023 after high interest rates and waning access to credit hit its cash position and made its debts unsustainable. The company emerged from bankruptcy after the appliance portion (Instant Brands) and the housewares portion (Corelle Brands) of the business were separately purchased by private equity firm Centre Lane Partners, one of the largest stockholders in Pyrex rival Anchor Hocking. After the purchase was finalized in early 2024, Centre Lane transferred ownership of Corelle to Anchor Hocking. This arrangement came into public awareness later in the year after Anchor Hocking announced that they planned to close Pyrex's 132-year old factory in Charleroi, Pennsylvania, and relocate production to Anchor Hocking's factory in Lancaster, Ohio. Senators Bob Casey Jr. and John Fetterman each criticized the move and demanded an explanation for how the merger of two major competitors was able to proceed without Federal Trade Commission oversight. A lawsuit by the State of Pennsylvania against Centre Lane Partners that attempted to halt the factory closure was dismissed by a federal judge. After months of uncertainty and multiple temporary closures, Anchor Hocking permanently closed the Charleroi factory in April 2025.

European history After Corning Incorporated divested itself of its consumer products division in 1998, Newell Cookware Europe retained its license to produce Pyrex in Europe, Africa, and the Middle East. France-based cookware maker Arc International acquired Newell's European business in early 2006 to own rights to the brand in Europe, the Middle East and Africa. In 2007, Arc closed the Pyrex soda–lime factory in Sunderland, UK moving all European production to France. The Sunderland factory had first started making Pyrex in 1922. Arc International sold off its Arc International Cookware division including Pyrex business in 2014, and the division was subsequently renamed the International Cookware group. London-based private equity firm Kartesia purchased International Cookware in 2020. In 2021, International Cookware acquired Pyrex rival Duralex for €3.5 million (US$4.2m).

Trademark

Pyrex remains a trademark of Corning Incorporated, but is licensed by two dinnerware manufacturers. Corning Incorporated continues to manufacture PYREX (all uppercase) laboratory glassware for international markets. The pyrex (all lowercase, introduced in 1975) trademark is now used for kitchenware sold in the United States, South America, Asia, and Australia. In Europe, Africa, and the Middle East, a variation of the PYREX (all uppercase) trademark is licensed by International Cookware.

Composition

… excerpt ends here. Continue reading the full article.

Illustrations

Pyrex logo as used by Corelle

Worked examples

Example 1 — a first encounter with Pyrex

Start with the simplest possible case. Write down what Pyrex claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pyrex before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pyrex ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pyrex

In research: Pyrex appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pyrex in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pyrex is common in secondary-school and first-year university syllabi. It links to neighbouring topics American brands, Boron compounds, Companies that filed for Chapter 11 bankruptcy in 2023, so understanding it makes those chapters shorter.
In everyday life: Look for Pyrex outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Pyrex in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pyrex means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pyrex out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pyrex in simple terms?

Why does Pyrex matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pyrex?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pyrex.