Emergency lighting is lighting for an emergency situation when the main power supply is cut and any normal illumination fails. The loss of mains electricity could be the result of a fire or a power cut and the normal lighting supplies fail. This may lead to sudden darkness and a possible danger to the 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 now 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: 2011 embraces residential hotels, clubs, hospitals, nursing homes, schools and colleges, licensed premises, offices, museums, shops, multi-storey dwellings, etc. Although this standard recommends the types and durations of emergency lighting systems relating to each category of premises, it should be remembered that the standards are the minimum safe standards for these types of building and that a higher standard may be required for a particular installation.