There are three main aspects of emergency escape lighting: 1) escape route lighting; 2) open area / anti-panic area lighting; 3) high risk task area lighting.
Escape route lighting is the part of an emergency lighting system provided to enable the swift and safe evacuation of a building by illuminating its escape routes, such as corridors and stairways, and also the location of fire-fighting equipment, e.g. fire extinguishers and safety / security equipment such as keyboxes holding emergency keys to exit doors. As such, escape route lighting can be seen to be a fundamental requirement of fire safety provision in all non-domestic premises and public areas of HMOs, whatever their use or occupancy levels.
Large public buildings such as shopping malls, museums and exhibition halls, etc., attract significant numbers of visitors who will not be familiar with the layout of the premises. Panic may therefore ensue should emergency evacuation be triggered by the sounding of the fire alarm. Open area / anti-panic lighting is relevant in such situations to aid in the identification of escape routes and exits and the guidance of people towards them.
High risk task lighting is a specific type of emergency lighting provided to ensure the safety of people involved in a potentially dangerous process or situation. It must be sufficient to enable the requisite shut-down procedures to be implemented. This type of lighting will only apply across a limited range of scenarios.
The above distinctions serve to emphasise the role of emergency escape lighting in fire safety and how it is adapted and applied, on a case by case basis, according to the specific use and occupancy levels of a particular building and / or areas within it.
What are emergency lighting luminaires?
There are two main types of luminaire, the relevant standard for which is BS EN 60598-2-22: self-contained and centrally supplied.
The self-contained luminaire, as it name suggests, contains all the essential components (i.e. battery, charger, control unit, lamp, diffuser and any test or monitoring facility) for it to function as an independent emergency light. As noted in the Fire Protection Association (FPA) Emergency Lighting Handbook (2012), this is the most common form of emergency lighting and is usually designed to be fitted to a wall or ceiling to illuminate a certain area or building feature. A typical example is the surface-mounted, rectangular bulkhead luminaire, although a wide range of self-contained luminaires is available including square, round and recessed / inset models.
Centrally supplied luminaires, also known as ‘slaves’ because they cannot function independently, are defined by BS EN 60598-2-22 as follows: “luminaire for maintained or non-maintained operation which is energized from a central emergency power system that is not contained within the luminaire”. Slave fittings contain the lamp and some of the control gear but the charger, battery and often the changeover device are located remotely and provide the supply to a number of luminaires. Again, the luminaires themselves come in a range of shapes and styles.