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 lampshades is covering two ways: chemical tempering and physical tempering.
Chemical temper is simple, after the pressed lampshades formed, immediately put the hot glass lampshdes into a specail liquid water to cool down, then take them out, this lampshades can not break into sharp shades when it fails, safe to skin.
However, the physical templing glass lampshades has four to five times stronger than COMMON glass and does not break into sharp shards when it fails. Tempered glass lampshades is manufactured through a process of extreme heating and rapid cooling, making it harder than normal glass light shades.
According to your situation, please choose right tempering glass covering for your lights!