Canada's
Institute for Research in Construction
CONSTRUCTION INNOVATION Volume 4 Number 4, Fall 1999
Photoluminescent
material holds potential as alternative to emergency lighting, research finds.
Photoluminescent material, which glows in the dark, can be as effective as conventional
emergency lighting in guiding people safely out of burning buildings, a new study by the National Research Council's Institute
for Research in Construction has concluded.
The study, conducted by IRC's Fire Risk Management Program in partnership with Public
Works and Government Services Canada, set out to assess the potential of photoluminescent material in assisting people to
evacuate buildings safely.
This material, which can be used in paints, sticky strips, fabrics, plastics or virtually
any other product, also has other advantages, including low cost and dependability, says study leader Dr. GuylËne Proulx.
"We
found that people could exit very easily and comfortably in the stairwell with the photoluminescent material," Proulx
explains.
"I
can't say whether it should supplement or replace existing types of emergency lighting, but I can say this material is very
promising," Proulx notes. "It offers good visibility in smoke, it won't fail during a fire even if there is a total
power failure, and it is still effective in some buildings where it has been installed for more than 20 years."
Proulx's
field study compared photoluminescent material to emergency lighting in the stairwells of a 13-storey office tower in Ottawa.
In two stairwells, photoluminescent strips containing zinc sulfide pigments were used to illuminate the stair nosings, as
well as the walls near the floor and at one metre above the floor.
One stairwell had the photoluminescent material
alone; another was fully lit by conventional lights. A third had a combination of photoluminescence and emergency lighting,
while the fourth had emergency lighting alone. Emergency lighting, powered by a back-up generator, is typically half to one
third as bright as standard illumination.
During the unannounced fire drill, building occupants descended the staircase lit only by photoluminescence more
slowly than the other three. However, the descent was slowed by bigger crowds, as well as by several firefighters working
their way up the stairs. Once those factors were taken into account, the evacuation speeds were comparable in all four conditions.
Some
people reported on a follow-up questionnaire that they would have liked more way-guidance strips - for example, on the inside
handrail and at each landing. One in three respondents who had exited in the stairwell with photoluminescent material alone
said the material should have been brighter.
Photoluminescent material can circumvent the problems commonly caused by smoke.
Improved
material made of alkaliearth aluminate is already available on the market. This new substance is 20 times brighter and glows
more than four times longer than the product tested in her study.
Unlike regular lights installed at intervals along a ceiling, photoluminescent material
can circumvent the problems commonly caused by smoke. For instance, the material can be attached in unbroken strips leading
outside, so that people don't panic, or get confused or disoriented. It can also be installed close to the floor, where it
is less likely to be obscured by rising smoke.
The photoluminescent material can be attached in unbroken strips leading outside
or it can also be installed close to the floor, where it is less likely to be obscured by rising smoke.
The photoluminescent
strips used by Proulx were installed according to the British standard covering emergency lighting. Indeed, the material has
been popular in Europe for some 20 years, and is mandatory in some places such as English Channel ferries as a way-guidance
system for emergency use. Its use in emergency way-guidance systems is not addressed by the National Building Code of Canada
1995, although it is sometimes used in this country as an additional evacuation measure.
Future NRC research projects could focus
on the effectiveness of the new photoluminescent material now available - which glows longer and brighter - in guiding people
from buildings or underground spaces.
