How to Recycle Pyrex/Heat-Resistant Glass
Glass baking dishes, casseroles, measuring cups, and oven-safe cookware. Not recyclable anywhere in container glass, and not made of what most people think it is made of.
Quick answer
Donate it intact, bin it broken. Glass bakeware is rejected by container recycling because it is a different formulation and it is tempered, so it behaves nothing like bottle glass in a furnace. Worth knowing: US Pyrex has not been borosilicate for decades, it is tempered soda-lime, which is exactly why it can shatter from thermal shock when it meets a wet counter.
- Recyclable
- Not curbside
- 1Wash it and check for chips, cracks, and scratches before offering it to anyone
- 2Donate intact pieces to a thrift store, where glass bakeware sells readily
- 3Take off any plastic lids or silicone sleeves and handle those separately
- 4Wrap broken pieces and put them in the trash, never in a recycling bin
- 5Retire any dish with a chip or deep scratch from oven use, since damage concentrates stress
- Thrift stores and donation centers, for intact pieces
- Buy Nothing groups and community swaps
- Regular trash, wrapped, for anything broken or chipped
The history here is widely misreported and worth getting right. Pyrex bakeware was borosilicate when Corning introduced it in 1915, but US consumer bakeware moved to heat-strengthened soda-lime glass decades ago. The Corning Museum of Glass dates the change to Corning itself beginning in the late 1940s, not to World Kitchen in the 1990s as commonly claimed, and Corning stopped making cookware entirely in 1998, with the PYREX name now used mainly for borosilicate laboratory glassware. The European licensee, International Cookware in France, genuinely does make tempered borosilicate, so European pyrex and US Pyrex are different products. Ignore the popular tip that uppercase PYREX means borosilicate and lowercase pyrex means soda-lime: the Corning Museum of Glass says the case change was a late-1970s rebrand and is not a reliable indicator of composition, and more than 150 glass formulations have been used under the brand. None of this changes the disposal answer, since neither type is accepted in container recycling.
Glass bakeware lasts for decades if it is not thermally shocked, so keeping a piece in use, or passing it on, is worth far more than any recycling route, of which there is none. The safety point is the practical one. The Consumer Product Safety Commission concluded that borosilicate is less likely to break under thermal shock while tempered soda-lime is less likely to break on impact, which is the tradeoff US manufacturers took. Consumer Reports lab work reported by the American Ceramic Society in 2012 found soda-lime cookware frequently failed when moved from a 450 degree oven onto a damp countertop, where borosilicate did not. Note that even original borosilicate Pyrex shipped with thermal-shock warnings in the 1930s, so the idea that old Pyrex was indestructible is nostalgia rather than fact.
- Donate intact bakeware, which is consistently in demand secondhand
- Keep using it, since undamaged glass bakeware has no meaningful service limit
- Repurpose measuring cups and casseroles as storage, organizers, or planters
Why can't Pyrex go in the recycling bin?
Because it is not container glass. Glass bakeware is a different formulation and it is heat-strengthened, so it does not melt or behave like bottles and jars in a furnace and shows up as unmelted inclusions or shifts the batch chemistry. A single dish can downgrade a load. Municipal guidance treats it alongside ceramics, porcelain, and dishware, all of which go in the trash when broken and to donation when intact.
Is Pyrex borosilicate glass?
Not in the US, and not for a long time. The Corning Museum of Glass states that US Pyrex bakeware has been made of heat-strengthened soda-lime glass for several decades, with the change beginning at Corning in the late 1940s rather than under World Kitchen in the 1990s. Corning left the cookware business in 1998, and the PYREX name now mostly denotes borosilicate laboratory glassware. The French licensee still makes tempered borosilicate, so European pyrex differs from American Pyrex.
Does uppercase PYREX mean it is the old borosilicate?
No, and this is a persistent myth worth ignoring. The Corning Museum of Glass says the switch from uppercase to lowercase was a rebrand in the late 1970s and is not a conclusive way to tell what glass a piece is made from. Over 150 different formulations have been used under the brand, including borosilicate, aluminosilicate, and tempered soda-lime, so the logo tells you roughly when a piece was sold rather than what it is.
How do I keep glass bakeware from shattering?
Avoid sudden temperature changes, which is what breaks soda-lime bakeware. Never set a hot dish on a wet counter, a damp towel, a metal trivet, or in the sink. Never use it on a stovetop, under a broiler, on a grill, or in a toaster oven. Preheat the oven fully before the dish goes in, and put liquid in the bottom before cooking meat or vegetables. Retire anything chipped or deeply scratched, since damage concentrates stress.
Recycling centers that accept Pyrex/Heat-Resistant Glass
RecycleFind lists recycling centers that accept pyrex/heat-resistant glass. Open a listing for hours, contact info, and directions.