PYREX vs. Pyrex: What's the Difference? | Corning

For many people, Corning is synonymous with PYREX® — and pyrex. Although both products are glassware and share the same spelling, they're distinctly different. To understand how each is unique and how they are used, explore the PYREX vs. pyrex differences.

What Is PYREX?

Corning first introduced an improved glass formula under the PYREX® brand name in 1915. At its core, Pyrex is glassware and cookware that can resist chemicals, electricity, and heat. It is also shock-resistant and can withstand thermal expansion. As a result, it's an appropriate material to make cookware. Pyrex is also well-suited for lab tools, such as beakers, flasks, and test tubes.

During the early days of production, Pyrex labware and cookware was constructed from borosilicate glass. Borosilicate glass is less expensive and more heat resistant than other substances. It can also be tempered to withstand a wide range of temperatures.

PYREX vs pyrex Construction Differences

Corning used borosilicate to produce all Pyrex products. However, the company that purchased the cookware products switched to soda-lime glass, adopting the name pyrex (spelled with all lowercase letters).

Corning continued to make its lab tools with borosilicate, dubbing these products to be PYREX (spelled with all uppercase letters). Borosilicate glassware can sustain the large, sudden temperature changes that frequently occur in labs without shattering. These products are also less likely to react to chemicals.

Corning sold the consumer products or cookware business in 1998. The new owner, known as Borden at the time, later rebranding to World Kitchen in 2000, recognized that the cookware didn't need to be quite as strong, and — to make it accessible to the average customer — it needed to be more affordable. With this in mind, they switched the cookware to soda-lime glass, a less expensive component. Soda-lime glass, now called pyrex, isn't as resistant to thermal shock, but it is durable enough for everyday cooking.

Benefits of PYREX Labware

PYREX labware is designed to meet the rigorous demands of scientific experimentation. In fact, these scientific glassware products were integral in developing penicillin during World War II and the polio vaccine during the 1950s.

Corning laboratory glassware products have long been manufactured to meet the quality and reliability standards created by the American Society for Testing and Materials (ASTM). Corning advanced its quality control for accuracy and precision further by testing its volumetric glassware in an ISO/IEC 17025 accredited laboratory.

PYREX glass is well-suited for lab work because Corning uses borosilicate to produce beakers, flasks, test tubes, and other lab glassware. PYREX lab glassware made with borosilicate can withstand harsh, corrosive chemicals, handle extremely low and high temperatures, and it can survive rapid temperature changes without sustaining damage. PYREX beakers, Erlenmeyer flasks, and round- and flat-bottom boiling flasks can be repeatedly heated up to 230ºC. PYREX volumetric laboratory ware can be brought to 150ºC. Overall, PYREX laboratory glassware has a temperature shock limit — or allowable difference between the temperature of the glass and any medium in contact with the glass (air, liquid, or solid) — of 160ºC.

Always check laboratory glassware for any cracks, scratches, chips, or hazing — these damages can cause the product to break while in use. If properly cleaned and not damaged, PYREX laboratory glassware is reusable.

Unique Cleaning Procedures for PYREX Lab Glassware

Despite being made of a strong, durable material, PYREX lab glassware requires specific care and maintenance. Ignoring the specific cleaning differences of PYREX labware can undermine the glassware's integrity and stability. If handled improperly, these products could shatter when exposed to high temperatures.

Always clean PYREX products with a non-abrasive glassware detergent either by hand or in a dishwasher. Do not exceed temperatures above 110°C during the cleaning process. Do not use abrasive brushes or scrubbing pads that can scratch the glass or its coating. In addition, limit exposure to any aldehydes, ketones, chlorinated solvents, or concentrated acids, because they can damage the glassware.

For over 100 years, Corning has been a trailblazer in creating innovative glassware products that can reliably and repeatedly meet users' needs. These products have accelerated scientific discoveries and enhanced human health.