While toughened glass is tough and long lasting, it does sometimes shatter.
Toughening is done by a process which compresses a thin surface layer of the glass. While this makes the glass item much more resistant to pressure or impact, a small surface chip or scratch weakens this surface layer. The chip or scratch may be small, but this is what can cause the glass item to shatter.
If toughened glass shatters, it frequently does so with a dangerous and frightening bang. Fortunately injuries are rare. The glass usually breaks into small square fragments, which are much less likely to cut than the jagged pieces from other kinds of glass. The fragments are similar to those from a shattered car windscreen. However, any shattered glass can still cut you, so be careful when handling and remember that toughened glass isn't unbreakable.
Using toughened glass safely
Examine items of toughened glassware occasionally, and get rid of any that are chipped or scratched.
Toughened glass may be weakened by thermal shock, so avoid extremes of temperature like putting very hot food on a glass plate that has been in the fridge.
Reporting an issue with toughened glass
If you have a safety problem or concern with toughened glass or glassware, let us know.