At 1:24 a.m. a loud crash came from the kitchen area. Nothing was evident – nothing dropped or fell to the floor – a mystery. Later that day, I opened a lower kitchen cupboard and glass fell everywhere, shards and small splinters. My Pyrex 9” x 13” glass baking dish had exploded on the shelf. It was by itself and hadn’t been used in weeks. A more confusing mystery to solve.
If you Google “exploding Pyrex dishes” you will read many frightening reports of this occurrence. Consumer Reports also has a list of stories. Pyrex changed their formula in 1999 and replaced borosilicate with another sand compound. Then the breakage started.
Pyrex explains this with “improper handling” and “temperature variance” with very few instances considering the millions of pieces in use. We are fortunate that our explosion did not occur in the oven, dishwasher, on the counter or while being placed in dishwater.
I did send a report to U.S. Consumer Products Safety Commission. A search for glass bakeware using borosilicate brought me to OXO. They clearly state that they use borosilicate to prevent shattering and breakage. This is what I now use. (I have no connections to OXO.) Please be cautious when using Pyrex and wear sturdy oven mitts.