Tempered glass is one of two kinds of safety glass regularly used in applications in which standard glass could pose a potential danger. Tempered glass is 4 to 5 times stronger than standard glass and does not break into sharp shards when it fails. Tempered glass is manufactured through a process of extreme heating and rapid cooling, making it far harder than normal glass.
In the rare case of breakage, the special processing of tempered glass causes it to shatter into small oval-shaped pebbles when broken. This eliminates the danger of sharp edges. Because of this property, and its strength, tempered glass is often referred to as safety glass.
The thermal process that cures tempered glass also makes it heat resistant. Tempered glass is used to make carafes in automatic coffee makers and the windows in ovens. Computer screens, skylights, door windows, tub enclosures and shower doors are more examples of places you will find tempered glass. Building codes also require the windows of many public structures to be made of tempered glass.