Exit signs are available in multiple shapes, forms, and materials for architects, engineers, and lighting designers to select from. It is essential to understand local and national codes to guide your specification. Some local codes are unique to the area, such as New York City and Chicago – where additional standards that differ from most national standards apply. (NEC) National Electrical Code and all Building Codes require exit signs in all public structures. Cost, location of use, building construction, design, maintenance, life expectancy, and installation types are all points to review when selecting what kind of exit sign will best meet the code and a final decision when making the specification. Indoor applications for exit signs have the largest selection of exit signs to select from. Among the potential choices will be whether the exit sign is electric or non-electric.
In this review, we examine the photoluminescent exit & egress signs. Photoluminescent signs (aka “glow in the dark signs”) are beneficial technology for creating a safe egress pathway to exit the building and create an area of safety. These exit signs interact with an illuminated light source, causing the signage to glow without applying an electrical load. These exit signs that do not require electricity are increasing in sales and popularity due to their ease of installation, long life, zero operating cast, and simple maintenance requirements. These non-electrical exit signs have life warranties of twenty years. When electricity fails in emergencies like tornadoes, hurricanes, earthquakes, and significant building fires, these egress signage and exit signs help by showing a path of egress for escape through an exit required in cities with tall buildings.
Photoluminescent signs require constant illumination under non-emergency situations. They must be able to illuminate for a long time in the dark when the power fails. Photoluminescent signs must utilize the proper charging light source specified by the manufacturer and the authority designating the sign. Under UL 924 requirements, a photoluminescent sign requires five-foot candles of illumination to charge appropriately. Photoluminescent signs are not allowed if the needed charging lights are off during occupied hours because of timers or occupancy sensors. Also, under UL 924, the photoluminescent signs and egress markers must work for at least 90 minutes when darkness occurs.
The IBC1031.1 code requires photoluminescent exit signs to be located within one hundred feet of any point in an area or within their listed viewing distance from the next closest sign. UL 924 lists photoluminescent signs for 50, 75, 100 or 125ft visual distances. What does this visual distance mean? If using signs with a 50ft view, you are required to have a photoluminescent sign guiding the pathway for those exiting every 50 ft until the exit is visible. To meet the UL 924 surface requirement, luminance needs a minimum of 0.06-foot candles. The Occupational Safety and Health Administration (OSHA) guidelines comply with UL924 guidelines for self-illuminous exit signs.
Here are general guidelines for the installation, monthly inspection, and testing of photoluminescent exit and egress signage.
- When installing a sign, make sure with a light meter that the sign receives no less than 5-footcandles and has a maximum viewing distance its listing requires in the dark.
- Ensure no controls for the sign’s charging light source are accessible to the public.
- Manufacturers and codes require chargeable light sources not controlled by timers, occupancy, or motion detectors. A 30-day monitor recording program is required to confirm that the system is always in working order.
- Follow the manufacturer’s directions and code requirements for surface mounting the egress signage and exit signs.
- Codes state that exit signs are inspected monthly for the operation of the light source, and a 30-second check of the illuminated signs in darkness is performed, which requires record keeping of this inspection.
When installed correctly, photoluminescent signs make excellent egress and exit signs to help occupants exit a building safely in an emergency.
