valerie has painful memories of last time she used pyrex. >> i removed my dish, closed the oven, turned, started to walk towards the consider, and boom, exploded. >> reporter: she was browning chicken under the broiler, something the instructions say not to do. her friend, carla fadden, however, was simply baking tomales when this? >> boom, i opened the oven, and to my great surprise, there was a moltedden melted mass. >> reporter: prompted by stories like valerie and carla, consumer reports conducted a one-year investigation of glass bake wear. it found reports of 163 shattering incidents, with 442 reports of injuries. it also prepared american-made pyrex and anchor hawking glass bake wear, made of soda lime glass to more expensive european pyrex made of a different material. testers put dry sand in the bake wear, which gets hotter than food, and put the dishes in an oven for 80 minutes at 450 degrees. then, straight from the oven, the dishes were placed on a wet granite counter. something else the product tells you not to do. 10 out of 10 times, the american-made bake wear broke. the european bake wear stayed intact at the same temperature. it finally broke at 500 degrees