The Lighting Council of Australia has raised concerns via a statement following the introduction of photoluminescent exit signs by the National Construction Code of Australia (NCC).
On May 1 2014, the NCC Volumes One, Two and Three will be adopted by all Australian states and will include a change which sees provisions for photoluminescent (PL) signs introduced as an alternative option to internally illuminated exit signs.
Photoluminescent, or glow in the dark, signs can absorb UV daylight and re-emit light once the source has been removed. In a draft statement last year, the Australian Building Codes Board detailed significant advantages of what they described as an innovative alternative for exit signs. They stated that photoluminescent exit signs offered “low installation and maintenance costs, little reliance on back-up electricity supply, a high level of redundancy and low ongoing running costs.”
Russell Loane, chairman of Lighting Council Australia, the peak body for Australia’s lighting industry, however, forecasts confusion and cost concerns following the introduction of PL signs.
“One of the major concerns is the confusion amongst electricians, building owners and building managers, as to how PL exit signs may be used,” he said. “If installed in accordance with the NCC amendment, PL signs will cost considerably more to install and maintain than the current electrically powered LED exit signs.”
“The installation of a PL exit sign typically requires the installation of two additional luminaires. Firstly, the NCC amendment requires that a PL exit sign must have a dedicated, uninterrupted light source continuously illuminating 100 lux onto the face of the sign. Secondly, the NCC already requires, via AS/NZS 2293.1, that an emergency luminaire must be installed within two metres of an exit door or typically where exit signs are located (AS2293-1 clause 5.4.1).”
Loane said such emergency lights are not necessary with electrically-powered exit signs, given that those signs give off enough light to serve as emergency lights. He noted that the addition of emergency lights created additional costs.
He added that PL signs would actually be more expensive to install and operate than conventionally-lit signs.
“The expected supply and install cost of a standard LED exit sign is in the order of $250, with ongoing energy costs of $3.16 per year. The supply and install cost of a PL exit sign and accompanying emergency light and separate luminating light source is in the order of $550, with ongoing energy costs of $21.56 per year,” he said.
He said potential non-compliance with emergency lighting regulations could create a huge safety risk for building occupants.
“It is therefore surprising the number of people who are not aware of their exposure to significant penalties for non-compliance with regulations regarding exit signs and emergency lighting,” he said.
Loane also detailed extensive penalties imposed for non-compliance with maximum penalties of $3 million dollars $3 million dollars for a corporation and significant financial penalty and up to five years imprisonment for individuals. In Victoria and Western Australia, maximum penalties for a corporation are $1.3 million dollars and $625,000 respectively along with significant financial penalties and possible imprisonment.
Loane also details common safety issues associated with the use of PL exit signs despite installing them correctly with the required additional luminaries.
“Even with the additional luminaries that must be installed with PL signs, there is a strong consensus view across a number of industry bodies, experts and academics that the use of PL signs significantly compromises safety,” he said.
“Exit signs have over 30 years of test and empirical data supporting the worldwide view that the safety of an exit sign is determined by its luminance level, and that the appropriate luminance level to ensure safe egress in an evacuation scenario (irrespective of the type of sign emitting it) is between 8cd/m² (candela per square metre) and 15cd/m². The amendment to the NCC provides for a luminance level for PL exit signs of 30mcd/m² (millicandela). One candela is 1000 times brighter than one millicandela.”
He said the 30mcd/m² figure was not nearly as bright as electrically powered signs – roughly 1/250th as bright as such signs must be. That, he said, could be especially dangerous in case of emergency, a claim backed by emergency personnel.
“When firefighters are in a smoke affected environment, the visibility of exit signs is an important safety aid, which will be compromised by the lower level of brightness of PL exit signs,” read a submission from the Metropolitan Fire Brigade, Building Code and Audits Division in Melbourne.
“It will be difficult to evaluate the compliance of a PL sign during essential services audits, and Fire Brigade Fire Safety Inspections,” Loane said. “I foresee issues with inspection and enforcement regarding the requirement for 100lx of illumination onto the face of these PL exits and as to whether the signs provide the requisite minimum light output. It is not difficult to envisage situations where a much cheaper, stick on, glow in the dark exit sign will be used in a non-compliant way. Essential life safety devices should not be put in a situation where they can be compromised in this way.”