Imagine a full blackout caused by a power outage in a facility whose back-up generators have failed.

Even in familiar surroundings, it is easy to feel trapped and panic is likely to strike.

In the World Trade Centre bombing of 1993, elevators and stairwells became pitch-black. Thick smoke blocked emergency lighting in areas powered by back-up generators, then water sprinklers flooded the generators causing total darkness.

“In these situations, photoluminescent safety markings come to the rescue as non-electrical emergency lighting. The markings absorb daylight or artificial light and emit a yellow luminance in full darkness,” says Marina Batzke, general manager, American PERMALIGHT Inc., Torrance, Calif., and chairperson of ASTM Subcommittee E12.13 on Photoluminescent Safety Markings.

“You may be well familiar with ‘glow in the dark’ Halloween items or toys for your kids,” explains Batzke. “The daytime colour of these gimmicks is similar to ‘photoluminescent safety markings,’ whereas the darkness-performance is severely lower.

Up to now, in numerous cases buyers were simply judging the daytime colour and accidentally bought cheap toy-type glow products for use in safety applications. Price rather than reliable, bright, long lasting performance was the decision-making factor.

In an actual emergency, such ‘glow in the dark’ low-glow products would not perform as needed and would not provide the necessary brightness to illuminate your escape route.”

Due to a lack of standards, it has been extremely difficult to judge whether true photoluminescent safety products or “glow in the dark” gimmick materials were installed as escape route markings.

To aid buyers of these products, ASTM published two new standards in 2000:

“These documents allow a clear distinction between ‘photoluminescent safety markings’ and ‘glow in the dark’ gimmick qualities,” states Batzke.

On site, a 100-mm [4 in.] wide safety marking has to emit minimum 15 mcd/m2 10 minutes after activation has ceased, and 2.2 mcd/m2 after 60 minutes.

This is identical with international standards, such as German DIN 67510 and IMO Resolution A.752(18).

In the ASTM specification, markings that do not fulfil these minimum luminance requirements are non-suitable for safety applications. Their use should be limited to Halloween, gimmick, and toy use.

“These new standards will avoid any future confusion among manufacturers, architects, code officials, and the ultimate users regarding sufficient luminance intensity and duration, proper installation and suitability for safety purposes,” says Batzke.

She initiated the standard-writing activity in 1995 with subcommittee members who represent code-writing organizations, users, producers, and general interest.

Additionally, E 2030, Guide for Recommended Uses of Photoluminescent Safety Markings, describes installation possibilities and provides drawings to highlight typical applications in corridors, staircases, and as signage (including escape route plans and ADA-compliant signs).

Copyright 2000, ASTM