A Guide to Emergency Lighting Design

A Guide to Emergency Lighting Design

In the event of a failure to the normal power supply, emergency lighting ensures its occupants can either safely evacuate or safely remain in the building until power is restored.

But who is ultimately responsible for emergency lighting? Fire Safety legislation places the duties defined onto the “responsible person” or a “person with duties”. This could be either the employer or the owner, who has control over the premises.

The responsible person is required to conduct a risk assessment to sufficiently identify the risks, which an emergency lighting design proposal must take into account.

Without a risk assessment, it can be difficult to complete an emergency lighting design, when considering the necessity and the right type of emergency lighting for each area. Should we base our calculations on only the minimum requirements, or are we to make the building as safe as possible?

Comprehensive consultation is therefore essential at design stage, which can include;

• The Responsible Person
• Owner/Developer
• Occupier
• Architect
• Installation Contractor
• Enforcing Authority
• Electricity Supplier

The consultation should decide how the building is to be used, and how an emergency lighting system will operate to ensure safety for its occupants.

A detailed building layout should also be submitted at design stage, where the areas that require emergency lighting are identified, and to what specification they should be lit. Details should also be provided relating to the mains lighting and how it is controlled.

The areas to consider include:

- Escape routes

- Potential hazards along escape routes

- Open areas

- High risk areas

- Safety equipment

- Lifts and/or moving stairways and walkways

- Toilets over 8m², facilities less than 8m² without borrowed light and those for use by disabled people

- Motor generator, control, plant and switch rooms

In addition to the above, emergency lighting must be placed near (i.e. within 2m of the below points of emphasis):

- Fire alarm call points and fire-fighting equipment

- First aid posts

- Escape route signs, including emergency exit signs at exit doors, directional escape route signs and all other safety signs

- Changes in level, including stairwells

- Changes in direction

- Each final exit and outside of the building to a place of safety

- Refuges and call points, including two-way communication systems and disabled toilet alarm call positions

- Manual release controls to release electronically locked doors as recommended in BS 7273-4

Types of Emergency Lighting

Escape route lighting is to assist the safe exit for its occupants, whilst ensuring that firefighting and safety equipment can be readily located and used. For escape routes which are up to 2m in width, the illuminance on the floor along the centre line shall not be less than 1 lux.

Safety signs are to provide appropriate visual conditions and direction finding to assist escape routes. Safety signs include escape route direction signs, emergency exit signs and other safety signs specified in the risk assessment.

Open area (anti-panic) lighting reduces the likelihood of panic and enables safe movement of occupants towards escape routes. Open area lighting should be used in any area over 60m², toilets for disabled and areas which form an escape route leading from an enclosed area. 0.5 lux minimum should be achieved at floor level, excluding a 0.5m wide border of the open area.

High risk task area lighting ensures the safety of people involved in a potentially dangerous process or situation and to assist proper shut down procedures to be carried out. Examples could be moving machinery, or the use of flammable materials. High risk areas shall not be less than 15 lux or 10% of the required task illumination, whichever is greater.

Standby lighting is intended to allow occupants to continue to operate the premises normally and should provide the same lighting conditions as those provided by the normal lighting system.

Emergency Lighting Systems: Decisions

Along with design considerations, the type of emergency lighting system must also be determined, in accordance with the requirements of the risk assessment.

Power Supply – An emergency luminaire can either be self-contained or centrally supplied (which can include distributed central battery (LPS), central battery (CPS) and generator/UPS systems). Self-contained luminaires must achieve their rated duration for at least 4 years of normal operation, while centrally supplied luminaires must use batteries with a declared life expectancy of at least 10 years at 20 °C ambient temperature.

Duration - BS EN 1838 defines a minimum duration of 1 hour for escape routes and open areas, however BS 5266 Part 1 expands on this; 1 hour should only be used if the premises are expected to be evacuated immediately upon supply failure and are not to be reoccupied until full battery capacity has been restored. A minimum duration of 3 hours is common practice as it allows for emergency responders and safety checks prior to re-occupancy and restoring mains power.

Testing and Maintenance - Regular maintenance, testing and servicing of the emergency lighting is crucial. The system should have means for simulating failure of the normal power supply for test purposes, either via a manual isolation switch or an automatic test facility. BS 5266-1 recommends both monthly short tests and annual full duration tests to ensure system reliability. Records should be kept of each test and the results logged accordingly.

Monthly (Short Functional Test)

• Simulate a mains power failure by switching off the normal lighting.
• Ensure all emergency lights illuminate correctly and stay on.
• Check for physical damage, obstructions, and cleanliness of fittings.
• Restore power and ensure battery recharging starts.

Annually (Full Duration Test - Required)

• Simulate a real power failure for the full rated duration (e.g., 1 or 3 hours).
• Ensure all emergency lights stay illuminated for their full duration.
• Verify proper battery recovery after power is restored.
• Check all luminaires, signage, and control equipment.
• Record results and address any failures promptly.

Record Keeping & Maintenance

• Logbook Required: All tests must be documented in a maintenance log, including:
  • Date of test
  • Duration of test
  • Issues found & corrective actions taken
• Corrective Action: Any failed lighting units must be repaired or replaced ASAP.

Emergency Lighting for Special Applications

Generally, for applications such as warehouses and offices, an emergency luminaire will emit white light while in operation, or in the case of an emergency exit sign, both white and green. However, in special applications such as laboratories, narrow spectrum light sources are commonly used. Red light is often applied in animal research environments to avoid disruption of the animals’ circadian rhythm. So, in order to preserve their behaviour, a red emergency luminaire may also be required.

BS EN 60598-2 states that to identify safety colours, the minimum CRI of an emergency escape luminaire shall be Ra>40. As red is only one part of the full colour spectrum when calculating CRI, its rating is undefined.

Therefore, narrow spectrum light sources should only be used for emergency lighting under very specific circumstances and must be justified as part of the risk assessment, ensuring that safety is not compromised. Emergency exit signs, safety signs and equipment must remain clear and visible, and the necessary lux levels (as per the design proposal) must still be met to ensure a safe evacuation.

Legislation

• Health and Safety at Work etc Act 1974
• The Workplace (Health, Safety and Welfare) Regulations 1992
• The Regulatory Reform (Fire Safety) Order 2005 for England and Wales, Fire Safety (Scotland) Regulations 2006 for Scotland and The Fire Safety Regulations (Northern Ireland) 2010 for Northern Ireland, Fire Services Act 1981 and 2003 for Ireland
• BS EN 1838:2013 Lighting applications. Emergency lighting
• BS EN 50172 Emergency escape lighting systems
• BS 5266-1 Code of Practice for the Emergency Lighting of Premises “As a code of practice, this part of BS 5266 takes the form of guidance and recommendations. It should not be quoted as if it were a specification, and particular care should be taken to ensure that claims of compliance are not misleading.”
• S. 3217:2013+A1:2017 Code of practice for the emergency lighting of premises
• S. 3218:2013+A1:2019 Fire detection and fire alarm systems for buildings
• BS EN ISO 7010 Graphical symbols
• BS EN 60598-2 Luminaires

Standards can and will change , so please ensure that you use the above as a guide and check for any changes and local differences, prior to putting any of the above into practice.