Why Tempered Glass Is Safer — And How to Tell If Yours Is Real

Every panel we ship is tempered — but “tempered” is a word a lot of suppliers use loosely. Here is what the process actually does to the glass, why it matters for a guard, and the one permanent marking that proves a panel is the real thing.

What is tempered glass?

Tempered glass is glass that has gone through a controlled heat treatment that leaves it 4 to 5 times stronger than standard annealed glass of the same thickness.

How it is made

The glass is heated past 1,150 °F (620 °C), then cooled fast with jets of air. That thermal shock locks the surface into compression and the core into tension — and it is those built-in stresses that make the panel strong.

Benefit #1: it carries the code loads

A 12 mm tempered panel meets the guard requirements for a 200 lb concentrated load and 50 lb per linear foot (IBC/IRC), and it shrugs off impacts that would take out standard glass.

Benefit #2: it breaks safely

If a panel does break — it takes a violent, concentrated impact — it crumbles into small blunt-edged cubes instead of long cutting shards. That single property is what drops the injury risk so sharply, and it is why tempered glass is the right material for a glass pool fence.

Benefit #3: thermal resistance

Tempered glass takes temperature swings of roughly 360 °F (200 °C) without failing — which matters on a south-facing deck, and matters more in a climate that goes from −22 °F to +95 °F in the same year.

How to check that a panel is genuinely tempered

Every tempered panel must carry a permanent etched mark in one corner — the “bug stamp”. It names the fabricator and the standard the glass was certified to. No bug stamp, no certified tempered glass. Check it on delivery, before anything gets installed.

Our commitment

All Groupe ENO glass is tempered and certified to CAN/CGSB 12, bug-stamped, and backed by a 10-year warranty. Browse our frameless glass railing systems, or get an instant price with the free 2D configurator.