Photoluminescent markings can light a worker's path to safety in the event of a blackout. But, up until now, a lack of standards has made buying these safety markings a guessing game. To help clear up the confusion, the American Society for Testing and Materials has recently published its recommended standards for photoluminescence.
Whether due to a blackout or a natural disaster, companies' electric power systems occasionally shut down. In these cases, even emergency lights can fail to illuminate. The resulting lack of visibility is not only hazardous but it can incite panic as well. Fortunately, there is a lighting system that doesn't rely on electrical power to lead employees to safety: photoluminescent markings. They store up energy while lights are on and emit a yellowish luminescence when cast into darkness.
Most people are familiar with photoluminescence through its non-emergency usage in the design of 'glow in the dark' novelties such as Halloween toys. The luminescence of these items is generally much lower than those required for use as safety markings. Because both types have a similar appearance in light, its difficult for buyers to differentiate. Without an accurate scale of performance, price, rather than assured brightness or longevity, has been the key factor in buying the product. The problem becomes apparent in an actual emergency situation when the low glow luminescent products do not provide the brightness required to illuminate an escape route.
In an attempt to provide a criteria when purchasing photoluminescent markings, the American Society for Testing and Materials (ASTM) has published two new standards to aid buyers--E 2072-00, Standard Specification for Photoluminescent (Phosphorescent) Safety Markings and E 2073-00, Standard Test Method for Photopic Luminance of Photoluminescent (Phosphorescent) Markings. E 2072-00 requires a 4" wide on-site photoluminescent marking to emit at least 15 millicandela per square meter after ten minutes in the dark and 2.8 millicandela per square meter after one hour. According to the ASTM, markings that do not fulfill this minimum requirement are not suitable for safety applications and should be limited to novelty use. E 2073-00 clearly outlines how to test the luminance and record the findings in a report format. In addition, E 2030-99, Guide for Recommended Uses of Photoluminescent Safety Markings, details proper marking installation and provides drawings to highlight typical applications in corridors, staircases and as signage, including escape route plans and ADA-compliant signs.
When a company is buying photoluminescent safety markings, whether it is just one sign or a full escape route system, they should ask their safety equipment supplier for products in compliance with the ASTM's standards. The supplier should have luminance certificates that cite the standards and list the luminance values for each of their products. Companies buying photoluminescent markings should remember that only those markings that meet or exceed the ASTM's requirements are guaranteed to perform properly in the event of a power outage.
Source: Photoluminescent Safety Markings Lead the Way When Lights are Out Rimbach.com, Sept. 2000 http://www.rimbach.com/home/ihnpage/articles/Sept2000/9-00-a3.htm