| I think you need to be careful about your words. 1) Pyrex cookware is NOT "likely to crack and split in microwave cooking". These incidents are RARE. 2) The Pyrex name (in the US) includes both soda lime and borosilicate glass. Warning about "Pyrex" is wrong - you should be warning either about soda lime glass, which include many brands besides Pyrex. 3) Thermal shock is much more likely to occur when moving glass from the freezer to the oven, or from the oven to a metal surface, NOT when cooking in the microwave. I went ahead and skimmed the video. Every example was of putting a hot pan into a cold liquid, with warnings about moving a hot pan to a cold metal surface, or using it to cook on a stovetop. There were no examples of shattering due to the microwave turntable, nor warnings thereof. 4) My microwave uses a glass turntable. Why doesn't it shatter? Where does the thermal shock come from between the glass container and the glass turntable? If the thermal shock is between those two, then surely your more worried the glass would shatter if you take it out of the microwave oven and put it on a metal countertop, yes? (I bet my glass turntable is made of soda lime glass.) 5) Glass shatters for other reasons, like dropping it. As I quoted, "the change to soda lime represents a greater net safety benefit", because soda glass is safer than borosilicate when that happens. Don't forget that borosilicate glass also cracks with thermal shock. See also the Wikipedia references, https://www.snopes.com/fact-check/exploding-pyrex/ and https://gizmodo.com/the-pyrex-glass-controversy-that-just-wo... . |
Hardly. Borosilicate glass has a very low thermal expansion coefficient compared to soda lime glass. Which translates into much lower mechanical stress due to temperature gradients.
This is why laboratory glassware is made from borosilicate glass. Such glassware can safely be held in a flame (kitchen: stovetop use), which is not safe with soda lime glass (tempered or not).
Breakage of soda lime glass may happen due to this difference in material properties.
For example: an oven dish 'burns', what do people do: rush it out of the oven (no problem), place it on a towel (no problem), or dump it in the kitchen sink. In the latter case: oven-temperature glass on ambient temperature metal plate. Bonus points if kitchen sink is wet for improved contact.
This "water splashes in sink" (or on kitchen countertop) causes certain areas of the oven dish to go to near-ambient temperature, while rest of the dish remains at near-oven temperatures. This is what causes difference in thermal expansion -> mechanical stress -> breakage. Small puddles of water in sink or kitchen counter are easy to overlook when someone's in a hurry because smoke comes out the oven. :-)
Hence the advice to place oven dish on DRY surface that conducts heat poorly, like towel, wood, or silicone sheet.
Borosilicate glass is much more likely to survive this type of abuse.
Note this says nothing of mechanical abuse like chip damage / scratches, dropping on the floor, hitting other objects, or some combination thereof. Tempered soda lime glass may well have an advantage there (but any object & its material has its limits of course).