What "tempered glass" actually means and why it matters for safety

Short answer: tempered glass is heat-treated to be roughly four times stronger than regular glass, and when it does break, it shatters into small, blunt pieces instead of sharp shards — which is why it's required near doors, floors, and wet areas.

How it's made

The glass is heated to a high temperature and then rapidly cooled, creating internal stress that makes the outer surfaces compress and the interior stay in tension — this is what gives it both extra strength and its safe-breaking pattern.

Why it matters for your project

Anywhere a person could fall into or through glass, tempered (or laminated) glass is required by code precisely because the failure mode is so much safer than standard annealed glass.