Chemical Tempered Glass Chemical Tempered Glass is a type of glass that has been strengthened by a chemical process. This process involves immersing the glass in a bath of molten salt, which causes the surface of the glass to be in compression, while the interior is in tension. This creates a stronger glass that is more resistant to breakage than annealed glass. Chemically toughened glass, chemically hardened glass is not as strong as tempered glass, but it is more affordable and easier to process. It is also a safer option than tempered glass, as it does not shatter into small, sharp pieces when it breaks.