Emergency Lighting

by Steve on June 1, 2010

Emergency lighting systems are normally required to operate fully automatically in the event of a power failure.  Their main function is to illuminate escape routes and fire exit signs and to enable people to evacuate a building safely when the power supply to the normal lighting fails.
The following article describes the different types of emergency lighting systems.

Emergency Lighting Systems

Types of System

Emergency lighting schemes are usually one of two types:

Non–maintained — where emergency lamps light up independently of the main power supply and come into operation only if the main system fails.

Maintained — where emergency lamps are illuminated at all times using the same lamp for both normal and emergency operation.  The lamp is operated from a battery which is charged from the mains lighting system.

Maintained lighting systems are normally used where low levels of light are permanently required.  Some examples would be  public places such as  cinemas, theatres and anywhere alcohol is served.

Sustained is a combination of the above and includes two sets of lamps. One operating on mains 240V AC supply, and the other from the battery supply in the event of mains failure, in short, a non–maintained system which can also be operated with mains lamps whenever the premises are occupied.

The type of system is identified by abbreviations signifying type and duration:

M3 : Maintained System, emergency duration 3 hours.

NM2 : Non–maintained System, emergency duration 2 hours.

S1 : Sustained System, emergency duration 1 hour.

Building Regulations also state that all kinds of emergency lighting systems must comply with the British Standard BS 5266–1, and IEE wiring regulations.

These guidelines apply to:

residential hotels; clubs; hospitals; nursing homes; schools and colleges; licensed premises; offices; museums; shops; multi–storey dwellings etc.

Minimum safety standards are recommended for types and durations of emergency lighting systems depending upon the category of premise. Therefore a higher standard may be required for certain installations.

Siting of luminaire’s/signs

Lighting units and signs should be sited so as to clearly show the exit routes leading to the final exits from the premises.

Where the exit route or final exit is not readily identifiable a sign should be utilized rather than a lighting unit.

Particular attention should be paid to individual stairways, changes in level, corridor intersections, changes in direction, the outside of each final exit, control/plant rooms, lifts, toilet areas over 8m2 (although in some peoples opinion all toilets of public access and especially those for the disabled should have emergency lighting).

Access to fire alarm call points, fire fighting equipment, should be clearly illuminated.

In general, if common sense is used when siting the luminaire and signs to cover these areas, then the completed scheme will meet most requirements.

Areas to be covered

There are British and European standards which require emergency lighting to be installed.  An emergency escape lighting system should normally cover the following ares:

•Each exit door;

•Escape routes;

•Intersections of corridors;

•Outside each final exit and on external escape routes;

•Emergency escape signs;

•Stairways so that each flight receives adequate light;

•Changes in floor level;

•Windowless rooms and toilet accommodation exceeding 8m2;

•Firefighting equipment;

•Fire alarm call points;

•Equipment that would need to be shut down in an emergency;

•Lifts and areas in premises greater than 60m2.

It is not necessary to provide individual lights (luminaire) for each item above, but there should be a sufficient overall level of light to allow them to be visible and usable.

How much lightBS5266 recommends the provision of a horizontal illumination at floor level on the centre line of a defined escape route (permanently unobstructed) not less than 0.2 lux and 0.5 lux minimum for anti panic areas to exclude 0.5 metre border around the room.

In addition, for escape routes of up to 2m wide, 50% of the route width should be lit to a minimum of 0.1 lux.

Wider escape routes can be treated as a number of 2m wide bands. The actual degree of illumination should be closely related to the nature of both the premises and its occupants with special consideration being given to old person’s homes, hospitals, crowded areas such as pubs, discos and supermarkets, and to whether or not the premises are residential.

Emergency Lighting Testing and Inspection Regulatory Fire Safety Order 2005 ARTICLE 17 – Requires a suitable maintenance regime to ensure relevant equipment is kept in an efficient state.   An emergency lighting system (other than those in cinemas and certain other specified premises used for entertainment) should comply with BS 5266-1:2005. BS5266 requires a systematic schedule of inspections and tests to be carried out at the following intervals: Function test (at least once a month) Check all emergency lights for of damage or disrepair.  Test to ensure that they operate in the event of mains electricity supply failure by breaking the supply to them to check that they operate satisfactorily. The supply must then be restored and the charging indicators must be seen to be operating correctly. This test must be performed at least once per month and the results logged. Discharge test (at least once a year) The emergency lights must be tested for damage and for operation of their full rated duration period (usually 1 or 3 hours). The supply must then be restored, the charging indicators rechecked and the results logged Note: BS 5266-1: 1999 allows a one hour test to be performed as an alternative every six months for the first 3 years of the system, but the guidance document to the Fire Precaution Regulations calls for the annual test at all stages of equipment life. To test an emergency lighting system you need to simulate a mains power failure on the normal lighting circuit or circuits or individual luminaire’s. This will force the emergency lighting system to operate and use the battery supply. Usually a single test switch is used for the whole building or a separate switch is used for each circuit. This means when you simulate the mains failure you have to walk the whole system to check all emergency lights are operating correctly. When you restore the mains supply you have to walk it again to check that they are recharging. After the tests the performance of the system should be recorded using a Log Book or other means. Testing and inspections must be kept up to date and an annual inspection should include the completion and issue of a test certificate. Risk during testing emergency lighting-  Because of the possibility of failure of the supply to the normal lighting occurring shortly after a period of testing, all tests should be undertaken at times of minimum risk.  Alternatively, suitable temporary arrangements should be made until the batteries are recharged. Emergency Lighting Risk Assessment ICEL 1008: EMERGENCY LIGHTING – Risk Assessment Guide Guidance on Emergency Lighting from the ECA Emergency Lighting Test Certificate Sample Read more about Sustained Emergency lighting and T5 Lamps used for Emergency Fittings Forums comments regarding types ofemergency fittings.


{ 9 comments… read them below or add one }

John Advent November 5, 2017 at 09:35

Lots of information on emergency lighting thanks very much for the post.

Chris Holder February 12, 2013 at 15:54

BS5266-1:2011 states that facilities used by disabled people, multiple closet facilities without borrowed light should have emergency illumination from at least one luminaire.

dave February 9, 2013 at 08:35

Is there any Legal Jargon for Emergecy Lighting in Disabled Toilets in a College/School envoiroment?The law staes that Escape routes/Exits should be clearly illuminated or show illuminated Sign,s,but what about the main area(w/c)

Chris Holder September 5, 2011 at 08:12

Barry, there is often confusion between maintained Exit Signs and maintained Emergency Lighting. The word mantained is used in both definitions, but has different meanings.

Maintained Exit Signs are specified in the BS for any building where the users are unfamiliar with the building layout and the escape routes. This means they have to be permanently illuminated at all times. So a building open to the public needs maintained Exit Signs.

A maintained light fitting is one where the same lamp is used for normal (mains) operation and emergency (battery) usage. A typical example is a 600 x 600 recessed modular fitting which has three or four lamps. All are switched by the mains, but one lamp is “maintained” – it operates in both mains and emergency conditions. That fitting could be switched off at any time, but is still classified as maintained, and doesn’t need to be permanently illuminated at all times.

I hope this helps.
Chris Holder
Lighting Systems Product Manager
Thorlux Lighting

Steve September 3, 2011 at 15:23

Hi Barry
Might be worth submitting this question to the forums at
You should get some interesting replies!

Barry Jenkins September 2, 2011 at 11:53

Can someone clarify that when a public building is occupied, in this case a court, do the emergency exit lights have to be illuminated, i.e. maintained!

Chris Holder September 20, 2010 at 15:38

A good overview of what is a complex subject.

If I might clarify one point: you quote BS5266:1 1999 which did allow for a six-monthly test of 1/3rd of normal duration (1 hour for 3 hour-rated luminaires), but this has been superceded by the 2005 edition, which drops the option of the six-month test. This updated standard calls for a monthly function test, basically to check the lamp will strike in emergency mode, and an annual full duration test, starting 1 year after installation.

However, many clients still haven’t caught up and will often specify the six-monthly test.

Steve July 14, 2010 at 20:39

Is it a legal requirement to have emergency lighting
in public toilet cubicles that are totally enclosed?

RB Grant June 20, 2010 at 21:06

Great post , excellent information on emergency lighting

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