Remember too that any scratches etc will weaken the glass and it'll be more prone to break.
We used to do a soil test back in school that involved heating samples in a sand bath to some pretty high temps. We'd always do it in the hood cause that sand would scratch the pyrex over time and every once in a while we'd have a catastrophic failure - think pyrex and sand exploding all over the place. On the bright side it did convince the lab manager to purchase new equipment from time to time...
We used to do a soil test back in school that involved heating samples in a sand bath to some pretty high temps. We'd always do it in the hood cause that sand would scratch the pyrex over time and every once in a while we'd have a catastrophic failure - think pyrex and sand exploding all over the place. On the bright side it did convince the lab manager to purchase new equipment from time to time...