Why has emergency and exit lighting been ignored?

Emergency and exit lighting seems to be an orphan in the building industry - it's perceived as being neither part of the fire industry nor part of the electrical industry. But it's an essential service that helps save lives in the event of an emergency, so how can we ignore it?

It's quite common for the fire industry to view emergency exit lighting as part of the electrical industry and vice-versa. After all, it's governed by the Building Code of Australia (BCA), which the fire industry is concerned with, but it has to be installed by licensed electricians who are governed by the Wiring Rules, not the BCA. The danger is that both industries believe it belongs to the other industry, with the potential for it to be inadequately carried out, unnecessarily putting building occupants' lives at risk. This was an issue when I worked in the fire industry a few years ago and still seems to be so today.

Building code

Part E4 of BCA 2006 Volume One states that the objective of emergency and exit lighting is: "In an emergency, to safeguard occupants from injury by having adequate lighting, adequate identification of exits and paths to travel to exits and being made aware of the emergency" and that "a building is to be provided with adequate lighting on failure of normal artificial lighting during an emergency and adequate means of warning occupants to escape and to manage the evacuation process and to identify exits and paths to travel to an exit".

To meet these criteria, exit signs and emergency lighting must be installed in buildings according to the code, where the definitions of building types and sizes and the sorts of emergency and exit signage required for them are spelled out, as well as where in these buildings they must be installed. But it refers to AS 2293.1 for the installation of these fittings, mandating compliance to this standard for contractors installing them.

AS 2293.1

AS 2293.1 is the primary electrical standard defining the design, installation and operation of emergency lighting and exit signs, covering system performance, emergency power supply, installation requirements and maintenance; but we'll focus only on installation.

The standard states: "Exit signs shall be mounted not less than 2 m and not more than 2.7 m above floor level, or immediately above the doorway if the doorway is higher than 2.7 m."

But there's a dilemma, according to Michael Duce, Clevertronics national systems manager, chair of Emergency Lighting Working Group (ELWG) and member of LG-007 standards committee that wrote AS 2293.1: "The standard paradoxically acknowledges the known detrimental effects smoke has on the visibility of escape signs and emergency evacuation lighting, suggesting that smoke [which obscures the signs] should be managed by other means, ie, ventilation or other techniques. BCA requires buildings to have fans with sufficient capacity to maintain tenable conditions for not less than 2 m above floor level for specific time periods, depending on building type. That's fine for keeping the smoke levels down so people can breathe, but smoke accumulates at the ceiling and can quickly obscure the emergency lighting and escape signage situated at such a high level."

Here's the dilemma - both standards say to put the signs high enough for them to be seen, but they're quickly obscured by smoke during a fire, the time when they're most needed. That may be okay for say, office workers who have a reasonable idea of where the exits are, but it would be a disaster in a shopping centre or hospital where occupants are transient through the premises.

LG-007 acknowledges this dilemma in the preface to AS 2293.1: "Further to the content of this Standard, the committee will investigate new techniques, new or developing energy sources and illuminants (eg, photoluminescent materials), new approaches such as wayfinding systems and also the effects of smoke on emergency lighting for possible inclusion in future editions of the AS 2293 series."

Stressing the importance of addressing this onerous issue, Duce continues: "BCA's general thrust is to ensure that the visibility of signage is sufficient to enable an evacuation route to be determined and followed, so building occupants can escape in a safe and timely manner. If this can't be done using the current mandated high-level emergency evacuation lighting systems in fire smoke, then alternative low-level lighting systems or supplementary technologies must be considered."

Some of the supplementary technologies Duce refers to include high-tech audible systems that Clevertronics and other companies developed recently that effectively guide occupants out of a building with little or no reliance on sight. I experienced this myself at a very graphic Clevertronics demonstration recently and was astounded how effective it was in guiding me through dense smoke, virtually blind.

Emergency evacuation expert Jim Breaden, a 40-year fire industry veteran and former managing director of Wormald and Stanilite, who currently consult with Clevetronics, adds to this call for action: "It's about time this was said and I hope this article encourages more open discussion on safety because it continually fails to occur. Many people, both in and outside the industry, simply see exit signs as just another light fitting installed every 24 metres. It's become a commodity: 'the green box we fix above doors that's supposed to come on when the mains fail'. When you point out that it's the ONLY method used to show the way out in an emergency and it's probably not designed to work in smoke, people look dumbfounded."

"All the money spent on controlling the spread of smoke isn't much use if you're caught in a building that's becoming smoke logged, obscuring your vision of the high-level exit signs. At stake is your safety and that of the fire brigade officers, whose motto for us is 'get out fast and stay out'."

"Importantly, even in relatively light and highly survivable fire smokes, your eyes will be affected - just the same as getting on the wrong side of a bonfire. Try seeing 24 m then. You're lucky to see 10!"

"The level of meaningful industry research leading to significant advances in safer low-level evacuation lighting or wayfinding products has been almost nil. AS 2293 was first introduced in 1978. The performance fundamentals are basically the same, but today's occupants face greater risks and building complexities than 30 years ago and we have a raft of new technologies that could assist evacuees transiting much faster in life-threatening emergencies."

"A lot has changed in the UK since the introduction of new fire safety rules last October, replacing the out-of-date regime of fire certificates. The updated rules require a 'responsible person' to carry out fire risk assessments that must be designed to keep occupants safe, should fire break out. This person must ensure fire protection measures are maintained. So fire safety engineering has become more important, with newer wayfinding systems appearing such as flashing arrows, running person signs, floor mounted wayfinding strips and low-level stair lighting. Overhead emergency lighting down stairs has always been questionable, particularly if it is an egress route."

Recognising the current shortcomings and disparities in our current emergency and exit lighting standards, professionals involved in this essential building service should endeavour to keep up-to-date with new and emerging technologies to ensure they contribute to the safety of occupants of buildings they provide electrical services into.

Current emergency and exit lighting Australian standards

 

Standard	Title
Building Code of Australia	Volume One Section E - Services and Equipment Part E4
AS 2293.1-2005	Emergency escape lighting and exit signs for buildings - System design, installation and operation