It wasn’t until 1972 that building codes were revised to mandate safety glass in doors and other high traffic areas. Until then hundreds of thousands of people suffered major injury including loss of limbs and even their life from an accidental fall into broken glass. We’ve all broken the glass that comes with picture frames. Those shards are deadly sharp. Imagine falling on that. No thanks.
Now we have safety glazing in all doors, side lights, any walking surface,the bathroom tub and shower enclosures, patio furniture and pretty much anywhere people might slip. There are two types of safety glass: Laminated and tempered.
Laminated would be found in your car windshield. It is made by laminating 2 pieces together with a PVB inner layer (polyvinyl butyral). If it is broken, the glass cracks but will stay together. Stores use laminated glass for their windows.
Tempered glass is manufactured by heating glass to 1200 degrees then cooled rapidly. The tension between the interior and exterior of the glass creates a kind of tension that increases the strength of the glass six fold! In the case of tempered glass, when broken, it shatters into small but blunt granules.
Do you know what type of door glass you have?