Today, the UL924 requirement code is now the standard for exit signs and emergency egress lighting. In the past, the majority of exit sign lettering used to be red, however, green lettering has become the present standard. While the specific coloring of exit sign lettering may be included in the local codes of a city or state, the new UL 924 standard listing for egress signage has no specific code requirements. As it pertains to photoluminescent exit signs and the color used by this type of marker, the lettering is code compliant and in accordance with the UL924 code.
There are several other UL924 requirements with which photoluminescent exit signs are compliant. The following will list those regulations that photoluminescent exit signs satisfy.
• Exit sign letters must be at least six inches high. The width of the stroke needs to be three-quarters of an inch, and the space between those letters must be three-eighths of an inch. If is business owner or building owner chooses a larger exit sign to use, the egress marker must increase proportionally in size to assure that the emergency exit marker is legible from a distance.
• UL 924 requirements have specified a minimum luminance of 0.06 feet lamberts. The original testing was based on the viewing distance of exit signs are based on a viewing distance of one hundred feet. There are two different variations of testing involved regarding the measurement of luminance. The first is the UL analytical luminance visibility test, which is done with a photometer at the required distance of one hundred feet for an accurate observation visibility test. However, there is an exception to the rule. This exception allows manufacturers to request for a testing distance of fifty feet, seventy-five feet, or one hundred feet. Once this test is completed, UL924 requirements mandate that these emergency egress signs be marked with the legible viewing distance.
• Self-Luminous egress markings such as photoluminescent exit signs are continuously powered by a self-contained source of energy. UL924 requires a date of replacement to be legible on the exit sign. Photoluminescent exit signs need exposure to ambient light to properly charge. These emergency markers are required to have a constant source of ambient light and are UL924 listed. UL924 requirements recommend floor proximity and egress markings for safety. These pathway marking systems are set to be installed in low level locations, including floors, walls, and low level areas.
UL924 approved for the materials used to develop photoluminescent exit signs to be examined for their suitability. UL924 requirements have been put into place to ensure your safety and the safety of others. GloBrite stands by, and is in full compliance with UL924 requirements. Please call GloBrite if you need any clarification with UL924 requirements and standards.