Emergency lighting is lighting for an emergency situation when the main power supply is cut and normal electrical illumination fails.

The loss of mains electricity could be the result of a fire or a power cut. Without emergency lighting this could lead to sudden darkness and possible danger to occupants, either through physical danger or panic.

Emergency lighting is normally required to operate fully automatically and give illumination of a sufficiently high level to enable all occupants to evacuate the premises safely. Most new buildings have emergency lighting installed during construction; the design and type of equipment being specified by the architect in accordance with current Building Regulations and any local authority requirements.
The British Standard provides the emergency lighting designer with clear guidelines to work to. BS 5266-1 relates not only to hotels, clubs, hospitals, nursing homes, schools and colleges, licensed premises, offices, museums, shops but also multi-storey dwellings. Although the standard recommends the types and backup durations for each category of premises, it should be remembered that standards define a minimum requirement and that a higher specification may be required for a particular application.

What is emergency lighting? 
Lighting that automatically comes on when the power supply to the normal lighting provision fails.

Emergency lighting is a general term and is sub-divided into emergency escape lighting and standby lighting.

Emergency escape lighting – that part of an emergency lighting system that provides illumination for the safety of people leaving a location or attempting to terminate a potentially dangerous process beforehand. It is part of the fire safety provision of a building and a requirement of The Regulatory Reform (Fire Safety) Order 2005.

Standby lighting – that part of an emergency lighting system provided to enable normal activities to continue substantially unchanged. This guide does not include standby lighting as it is not a legal requirement and is a facility that may or may not be needed, depending on the use and occupancy of the premises.

Emergency escape lighting is itself sub-divided into escape route lighting, open area lighting and high risk task area lighting.

Escape route lighting – identifies the escape route and keeps it sufficiently lit. This includes illuminated fire exit signs but also emergency lighting such as emergency lighting bulkheads.