Ever since the first Neanderthal used light from a burning torch to check that a cave was empty before venturing inside, it’s true to say that lighting and security have become almost inseparable. It’s also true to say that security staff will – for the most part – have to rely on good lighting to see what people are up to on any given premises (infrared cameras notwithstanding). We also need light, of course, so that we can see where we’re going.
Consequently, when a building’s internal lighting is extinguished through a mains failure, or visibility is obscured by smoke from a fire, there are two immediate security risks.
If such a scenario develops in a retail environment, for instance, it presents an ideal opportunity for the less-honest customers to fill their pockets while the building is being evacuated.
More importantly, in a multi-level office building there’s a very real danger that people will not be able to find their way out.
That’s the main reason, of course, why non-domestic buildings are required to have emergency lighting and illuminated exit signs that ‘kick-in’ in the event of a mains failure, or when there’s a fire.
So that security guards can target shoplifters, the emergency lighting levels need to be relatively high. For other types of building or installation, they need only be good enough to allow staff to find their way to the designated exits. In some cases, the latter will only need to last until the back-up power supply comes on stream. In other situations, emergency lighting will need to remain on long enough such that a safe evacuation – and subsequent checking – of the building may take place.
Emergency lighting regulations
Whatever the specific requirements of your particular building/buildings, there are a couple of changes to the regulations relating to emergency lighting of which end users need to be aware (if only to check that their contracted installers are meeting the required specifications).
One of the most far-reaching of these changes is the recent implementation of ‘BS EN 1838: Lighting applications – emergency lighting’, a standard that applies the best practice principles long-encouraged and promoted by the UK’s own Industry Committee for Emergency Lighting (ICEL).
Possibly the most significant change that this standard introduces relates directly to the required levels of illuminance (ie lighting levels under emergency conditions at floor level), those levels being measured in lux. BS EN 1838 also introduces an additional area type category – plainly defined as ‘high risk task areas’ – intended to encompass any location where the safety of occupants is placed at risk by a dangerous process or situation if the ‘normal’ building lighting should fail.
Without going into too much technical detail, BS EN 1838 increases the amount of light that’s required on emergency escape routes from 0.2 lux to 1.0 lux. It also requires that a minimum of 50% of that ‘lighting value’ should be achieved over not less than half of the width of any given emergency escape route.
However, a special exception has been built-in to the standard for UK installations, otherwise known as an ‘A-deviation’. Effectively, this permits the former lux levels of 0.2 on the centre line and 0.1 lux minimum over the width to remain acceptable – as long as the escape route is permanently unobstructed.
In practice, of course, it’s virtually impossible to guarantee that an escape route will never be prey to obstructions – a temporarily-resident cleaner’s trolley would count as an obstruction for the time that it was there. Consequently, the majority of escape routes will have to be lit to the new standard of 1.0 lux, especially as any changes of level or direction (stairs, corridor intersections and exit doors, etc) must have a minimum lighting level of 1.0 lux in any case.
Security managers should note that this five-fold increase in light levels doesn’t necessarily mean using five times as many emergency lighting fittings (or luminaires). Emergency lighting luminaires and the light sources (or lamps) they use have improved dramatically in the last decade or so, and it will usually be possible to comply with the new UK standards by installing only a few extra fittings.
For ‘open’ areas, BS EN 1838 requires not less than 0.5 lux at the floor level of the core area, excluding a 0.5 m border area around the perimeter of the area. An open area is defined as one of more than 60 m2 where there is no fixed escape route, where there may be obstacles and where there are many ways around these obstacles to reach an identifiable escape route.
The new category concerning high risk task areas requires much higher light levels, defined as a minimum of 10% of the required maintained illuminance for the task – or 15 lux. Whichever is the greater. For example, if a given task requires light levels of 500 lux ‘on the working plane’ (ie at desk level), the emergency lighting installation must provide a level of at least 50 lux.
Fire precaution risk assessments
Another important change has followed on from the implementation of the Fire Precautions (Workplace) Regulations 1997, and the subsequent deregulation of some premises previously covered by fire certificates.
What this effectively means is that the owners or occupiers of premises where people are employed must now carry out fire precaution risk assessments (unless the premises have a current fire certificate, or are presently being assessed for a fire certificate).
In terms of emergency lighting, the risk assessment must include assessing the means of escape and reducing the escape times (if necessary).
Clearly, one of the factors affecting the speed of evacuation of a building is the emergency lighting – and how well it is designed, installed and maintained. The type of emergency lighting required is determined by the risk assessment, but in any workplace that has electric (or ‘artificial’) lighting there will always be a requirement for some form of emergency lighting provision.
Furthermore, for those workplaces in which five or more people are employed there is a legal requirement under the Health and Safety at Work Act to document significant findings of the risk assessment – and the measures proposed to deal with them. All staff and/or their representatives must be told about risk assessment findings.
In practice, it will normally make sense to bring in an outside contractor to physically carry out the risk assessment procedures, though in-house staff can perform the task if properly trained (a guide to the requirements of the risk assessment, along with a checklist of the necessary tasks, can be found in the ICEL document ‘ICEL 1008: Emergency lighting risk assessment guide’).
Safety and performance
In every aspect of emergency lighting, there is little point in carefully designing and assessing the system if the luminaires don’t perform as they should do. There have been many reported cases of fittings not living up to the standards claimed by their manufacturer – which, in fact, was the underlying reason behind the formation of ICEL and the ICEL 1001 registration scheme that provides independent verification of manufacturer claims.
Indeed, ICEL 1001 actually goes further than the relevant standards relating to the performance of emergency lighting luminaires – namely EN 60598-2-22, EN 60924 and EN 60925. These standards address the main points of safety and performance, but there are several important criteria not addressed (including such issues as flammability, photometric data, life expectancy and battery performance). These are covered by ICEL 1001.
In specifying ICEL-certificated emergency lighting luminaires, the end user can have complete confidence that they will perform as they are supposed to, with all member company lighting suppliers having been registered to ISO 9000. Then, as long as the system has been correctly designed, installed and maintained, the security/facilities team can be assured of legislatory compliance.
Bernard Pratley is technical manager at the Industry Committee for Emergency Lighting (ICEL)
