Review on 6/7 Cup Fuchsia Pyrex (2) 7402-PC, 4 Cup Purple Pyrex (3) 7201-PC, 2 Cup Lawn Green Pyrex (2) 7200-PC, 1 Cup Red Pyrex (2) 7202-PC Replacement Food Storage Lids by Ryan Lawson

I love Pyrex cookware myself, but the quality of their plastic lids is NOT as it used to be at all temperatures. My old pyrex plates have cases that last for years even with hot food. These new shapes quickly and permanently deform and change shape if you make the mistake of covering hot food or leaving it, even loosely, on top of food while it's being heated in the microwave. Once they deform, externally or internally, the case will no longer fit securely or at all. Pyrex, what has changed in the chemistry of your coating that has made it less reliable?