The process of tempering glass makes the glass stronger and causes it  (when you break it) to shatter into small pieces instead of breaking into jagged pieces like annealed (non-tempered) glass. These smaller pieces are less likely to cause injury when broken.

• Approximately 5x stronger than annealed glass. 
• Suitable as safety glass (in doors, hazardous locations such as showers and <18" from ground)
• Increases wind load