I just did it a minute ago, I was pouring some plastics and my pyrex glass just shattered on me and literally exploded! I got some on my shirt and shorts and shoes, luckily I was quick enough to not get my skin burned too bad, a couple small little blisters from drops of plastic. I am literally baffled on how this could happen, I did not rapidly cool or heat it for a long period, just like usual times 1 min. Microwave and 15 sec. each until pourable. I was pouring and boom the thing exploded! I just wan to know if this has ever happened to anybody Else, or what went wrong?

I looked at the bottom of a pyrex here and it says do not microwave or use on stovetop.  My guess is that the pyrex and plastic heated a differently in the microwave so when you poured the cooler plastic caused the glass the shatter.

I don't know if all pyrex is the same or not... maybe some are and some are not microwave safe.  ?

Glad you are ok though!!  

I am not a pro, but I have gone through about 15 gallons of plastic in the last year and used pyrex almost exclusively with no problems.  However, I have heard of this happening on occasion, especially with Anchor brand cups, which I also use.  Usually it is due to transfering the hot cup to a colder environment.  Ofcourse you said that was not the case.  However if the glass had a small hairline crack in it, it may not have to take much of a temp drop to cause the explosion.  I've had a few small burns myself and it is no fun .  Glad to hear your OK.

TJ

This will happen from time to time. :-X  Water is also a major factor with exploding cups.  Make sure there is no water anywhere near the plastic.  I also use Pyrex and Anchor. I have poured thousands of cups of plastic and have had only two crack on me.  Luckily they did not explode.  I know a couple of guys that were not so lucky and had to make a visit to the hospital.  I always inspect the cups each time before I pour, just in case.