Full tempred glass is approximately four times stronger than annealed glass of the same thickness and configuration, and residual surface compression must be over 10,000 PSI in accordance to American Standards ASTM C 1048. When broken it wil break into many relatively small fragments, which are less likely to cause serious injury. The typical process to produce tempered glass involves heating the glass to over 1000 degrees, then rapidly cooling to lock the glass surface in a state of compression and the core in state of tension.
Toughened glass is used when strength, thermal resistance, and safety are important considerations.
Automobiles: The most commonly encountered tempered glass is that used for Front and rear windows in automobiles
Buildings and structures: Toughened glass is also used in buildings for unframed assemblies (such as frameless glass doors), structurally loaded applications, and any other application that would become dangerous in the event of human impact.