Emergency lighting is lighting for an emergency situation when the main power supply 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 required to give illumination of a sufficiently high level to enable persons of all ages to evacuate the premises safely.
The British Standard provides the guidelines for emergency lights. British Standard BS 5266: Part 1: 2005. Although this standard recommends the types and durations of emergency lighting systems relating to each category of premise it should be remembered that the standards are minimum safe standards for the types of premises and that a higher standard may be needed for a particular installation.Most emergency lights fall into one of the following categories: