PYREX vs. pyrex: What's the Difference? Many people associate Corning with both "PYREX®" and "pyrex" glassware, but these two terms refer to distinct products with different compositions and uses. What Is PYREX? History: Corning introduced PYREX® in 1915 with an improved glass formula. Material: Originally made from borosilicate glass, which is resistant to chemicals, electricity, heat, and thermal shock. Uses: Suitable for both cookware and laboratory glassware like beakers, flasks, and test tubes. Properties: Shock-resistant and can withstand thermal expansion. Borosilicate glass is heat-resistant and less expensive than alternatives. Construction Differences Between PYREX and pyrex PYREX (uppercase): Corning continues to produce this brand of laboratory glassware using borosilicate glass. Can endure rapid, large temperature changes typical in labs without shattering. Chemically resistant and durable. pyrex (lowercase): Consumer cookware originally produced by Corning but later sold (in 1998) to another company. Cookware production switched to soda-lime glass, a less expensive but less heat-shock resistant material. Soda-lime glass cookware is durable for everyday cooking but not suitable for extreme temperature changes. Benefits of PYREX Labware Used in key scientific milestones (e.g., development of penicillin and the polio vaccine). Manufactured to meet ASTM quality and reliability standards. Volumetric glassware tested in ISO/IEC 17025 accredited labs. Withstands harsh chemicals, extreme temperatures, and rapid temperature variations. Temperature capabilities: Beakers, Erlenmeyer flasks, boiling flasks: repeatedly heated up to 230ºC. Volumetric labware: heated up to 150ºC. Temperature shock resistance up to 160ºC difference. Glassware is reusable if properly maintained and free of cracks or damage. Cleaning and Care for PYREX Lab Glassware Requires specific cleaning to maintain integrity. Use non-abrasive glassware detergents by hand or in dishwasher. Avoid exceeding 110ºC during cleaning. Do not use abrasive brushes or scrubbing pads. Limit exposure to aldehydes, ketones, chlorinated solvents, and concentrated acids. Proper care prevents shattering and ensures durability. Additional Resources PYREX labware products PYREX glassware education and safety webinars. New Lab Startup Program offering kits and resources for trying PYREX products. --- Corning has been innovating glassware for over 100 years, providing reliable products that accelerate scientific discovery and improve health. The key difference between PYREX and pyrex lies in their glass composition and intended use — PYREX for high-quality labware using borosilicate glass, and pyrex for consumer cookware made from soda-lime glass.