Fire-rated glass is classified using a performance rating (E, EW, or EI) together with a time rating, such as 15, 30, 60, 90, or 120 minutes. This indicates the minimum period for which the glazing system is designed to provide fire protection under standard fire test conditions.

It is important to understand that fire-rated glass should never be considered as a standalone glass pane. The fire rating applies only to the complete tested system, which includes the glass, the approved framing system (timber, steel, or aluminium), fixings, seals, and installation method. Any modifications to the tested assembly without additional testing or certification may invalidate its fire rating. Always consult the project designer, architect, or local fire authority to determine the correct fire-rated glazing classification for your application.

When selecting fire-rated glass, several environmental and operating conditions should also be taken into account, including UV resistance, exposure to extreme temperatures, and frost conditions. Correct installation methods and the orientation of the glass are essential to ensure both its fire performance and long-term durability.