Pyrex has changed it's cookware glass and people are finding out to
injury that Pyrex will explode.
I suggest people visit the link on Consumer Affairs to read the accounts
as having glass explode in one's eyes is not something anyone wants.
Pyrex seems highly unstable after being heated as one report showed a
measuring cup exploded after being washed and setting at room
temperature all night.
Advice is simple. Throw that crap out and warn your family to search
through their cookware as Pyrex with "soda lime glass" will explode as
it is not the old Pyrex which would simply crack when uneven heated.
http://www.consumeraffairs.com/homeowners/pyrex.html
The personal stories on the site are quite interesting reading in how
dangerous Pyrex has been for families.