I own and use several items of PYREX brand cookware, from casserole dishes to measuring cups. I like using it. By extension, I've always respected its manufacturer, Corning Glass. I think it's good to be doing one thing and doing it really well.
What I've just discovered is that Corning switched from making cookware out of its original formulation of glass back in 1998. The original was borosilicate glass, the same type as is used in laboratory equipment. These days, it is tempered soda-lime glass. The tempering process makes this cheaper type of glass stronger, but puts extra stress on the interior. That means that, when the glass is about to break, it breaks more violently.
Corning denies that there's any danger in the new formulation, but there are lawsuits. It also says that some of its PYREX kitchenware was made from the soda-lime glass even before 1998. However, I won't buy any of the newer formulation.
Here's how you tell: prior to 1998, American-made kitchenware had PYREX (R) printed in all-capital letters; after 1998, it used lower-case. Like this:
See the difference in the trademarks?
Also, the rights to use the PYREX trademark in Europe went to the French company, Arc. It continues to make its products from borosilicate glass, and it continues to use capital letters for the PYREX name. You can find its products here: https://icedteapitcher.myshopify.com/.
More about the switch in PYREX glass formulas:
http://nowiknow.com/the-war-against-pyrex/
https://gizmodo.com/the-pyrex-glass-controversy-that-just-wont-die-1833040962?utm_source=quora&utm_medium=referral
