There is three type marking for fire proof glass classification.
The available periods are 30, 45, 60, 90, 120 minutes.
| Class | Resistant |
| E (time) | Flame resistant |
| EW (time) | Flame resistant and avoiding limited radiation |
| EI (time) | Flame resistant and keeping heat |
The thickness of fire proof glasses varies according to exterior or interior applications. If a fire proof glass is used for double glazing unit,it is obligatory that fire proof glass has to replaced against possible fire danger.
