A system of emergency lighting is provided within the escape routes and common parts of the building. This is necessary to provide a minimal light level for evacuation or emergency service operations in the event of a power failure to the normal mains lighting for the area. The system is installed and maintained to BS5266.

A non-maintained system means that the light fittings do not serve another purpose and have an internal charger and battery system that switch to their 'emergency' mode automatically when the supply to the lighting circuit is removed.

The fittings generally have an expected lighting duration of three hours and will require up to 24 hours to recharge if the batteries are exhausted.

It is essential that emergency lights are always connected to the local lighting circuit. Where this is not the case they cannot be relied on to operate correctly.

Emergency lighting should be provided with a test facility that does not disconnect the power supply from the normal mains lighting for the area it services.

Emergency lighting may be used to illuminate fire equipment and wayfinding signage, but where this is the case additional lights may be required for the means of escape.