Question 1

What is emergency lighting?

Accepted Answer

Emergency lighting is a secondary lighting system that activates automatically when the normal mains electricity supply fails, providing sufficient illumination to allow the safe evacuation of a building and the safe use of escape routes and fire safety equipment. It is designed to operate when normal lighting fails - whether due to a fire cutting the electrical supply, a power cut, or a fault - and must function without any manual intervention. Emergency lighting specified to BS 5266-1 must provide a minimum illuminance on escape route floors of 1 lux at floor level along the centreline of escape routes, and 0.5 lux in open areas used for escape. In addition to general illuminance, emergency lighting must also illuminate safety signs (exit signs, directional signs) and fire safety equipment locations (fire alarm call points, fire extinguishers, manual controls for doors). Emergency lighting units are available as self-contained luminaires (with a built-in rechargeable battery that charges from the mains and switches to battery on mains failure) or as part of a central battery system.

Question 2

What are the BS 5266 emergency lighting categories?

Accepted Answer

BS 5266-1 defines emergency lighting categories based on the duration of emergency operation required. Category M: minimum 1-hour duration - for premises where rapid evacuation is expected (small premises, low-risk). Category 1: 1-hour duration - for most commercial and public buildings where occupants are familiar with the building and rapid evacuation is feasible. Category 2: 2-hour duration - for premises where occupants may not know the building (hotels, hospitals, some public buildings). Category 3: 3-hour duration - for high-risk premises where a longer evacuation time may be required. The category required is specified by the fire risk assessment for the building. Additionally, emergency lighting may be specified as 'maintained' (the luminaire operates all the time, on mains power normally and on battery when the mains fails - used where light levels must not suddenly change, as in theatres) or 'non-maintained' (the luminaire is off during normal operation and only illuminates on mains failure - the more common type for most commercial buildings).

Question 3

When do buildings need emergency lighting under Building Regulations?

Accepted Answer

Building Regulations Approved Document B (Fire Safety) requires emergency escape lighting in specific locations. For non-residential buildings, emergency escape lighting is required on all escape routes and in all areas where people may need to find their way to exits, particularly: internal corridors and stairwells; areas without natural light where people could be trapped; rooms with an occupancy of 60 or more; and rooms that contain potentially dangerous equipment (plant rooms, etc.). For residential buildings (dwellings), Approved Document B does not generally require emergency lighting in individual dwelling units, but it does require emergency lighting in common areas of blocks of flats (corridors, stairwells, and lobbies). The Regulatory Reform (Fire Safety) Order 2005 (which applies to non-domestic premises) also requires emergency lighting where necessary for the safety of relevant persons - this requirement is assessed through the fire risk assessment, making the competent fire risk assessor the key decision-maker for most commercial buildings.

Question 4

How is emergency lighting tested and maintained?

Accepted Answer

Emergency lighting requires regular testing and maintenance to ensure it will function when needed. BS 5266-1 specifies the testing regime: a monthly function test (pressing the test button on each unit to verify the lamp operates - duration typically 5 seconds, just enough to confirm the lamp lights); an annual full duration test (the full rated duration test, typically 1 or 3 hours, to verify the battery can sustain the emergency period - this test will typically discharge the batteries fully and should be planned for a time when the building is unoccupied or evacuation is not reliant on the lighting system). Self-contained units contain rechargeable batteries that must be replaced periodically - typically every 3-4 years for nickel-cadmium batteries and 5-7 years for lithium batteries. A record of all testing must be kept in the building's fire safety log book. Failure to test and maintain emergency lighting is a breach of the Fire Safety Order obligations for the responsible person.

Emergency Lighting

Just so you know...