Emergency Lighting is designed to come on when the mains fail. It is usually provided for safety reasons and to enable uninterrupted occupation of a building in times of breakdown of the main lighting. It also provides lighting for escape routes in the case evacuation at a building is necessary.

The most widely used and economical systems are stored energy systems using secondary batteries specifically designed for long term stand – by use.

Design Criteria
When designing emergency lighting, the following points must be considered:
Purpose of the emergency lighting
[ a ] Directional Escape Signage
[ b ] Standby Lighting Luminaire

Basic Requirements of Emergency Luminaire
The basic requirements of emergency lighting are:
i ] To indicate clearly and unambiguously, usually with the use of exit signs, the escape routes;
ii ] To provide illumination along the escape routes using luminaires spaced at the appropriate distances;
iii ] To provide, where required, standby lighting to permit normal and safe occupation of the building; iv ] To provide, where required, security lighting to prevent injury or thereats to persons