Toughened or tempered glass is glass that has been processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. Tempered glass is made by processes which create balanced internal stresses which give the glass strength. It will usually shatter into small fragments instead of sharp shards when broken, making it less likely to cause severe injury and deep lacerations. As a result of its safety and strength, tempered glass is used in a variety of demanding applications, including passenger vehicle windows, glass doors and tables, refrigerator trays, as a component of bulletproof glass, for diving masks, and various types of plates and cookware.
Toughened glass is physically and thermally stronger than regular glass and is used when strength, thermal resistance and safety are important considerations. Tempered glass is also used in buildings for unframed assemblies (such as frameless doors), structurally-loaded applications, and any other application that would become dangerous in the event of human impact.