Exit And Emergency Lighting
Numerous regulatory agencies and codes govern emergency lighting and exit sign requirements. Aside from being code compliant, employers must also follow the requirements of their local authority having jurisdiction (AHJ). Chicago has their unique codes and requirements for exit signs and emergency lighting. Reach out to your local fire marshal or inspector to see what the codes are regarding local emergency exit requirements.
Under 29 Code of Federal Regulation (CFR) 1910.34(c) OSHA defines “exit route” as, “a continuous and unobstructed path of exit travel from any point within a workplace to a place of safety (including refuge areas).” An exit route includes all vertical and horizontal areas along the route and consists of the following three parts:
Exit Access−means that a portion of an exit route that leads to an exit. An example of exit access is a corridor on the fifth floor of an office building that leads to a two-hour fire-resistance-rated enclosed stairway (the Exit).
Exit means that portion of an exit route that is generally separated from other areas to provide a protected way of travel to the exit discharge. An example of an exit is a two-hour fire-resistance-rated enclosed stairway that leads from the fifth floor of an office building to the outside of the building.
Exit Discharge−means the part of the exit route that leads directly outside or to a street, walkway, refuge area, public way, or open space with access to the outside. An example of an exit discharge is a door at the bottom of a two-hour fire-resistance-rated enclosed stairway that discharges to a place of safety outside the building.
OSHA’s requirements for lighting and marking exit routes are covered under 1910.37(b). It states that each exit route must be adequately lighted so that an employee with normal vision can see along the exit route and each exit must be visible and marked by a sign reading “Exit.” Additional requirements include the following:
Each exit route door must be free of decorations or signs that obscure the visibility of the exit route door.
If the direction of travel to the exit or exit discharge is not immediately visable, signs must be posted along the exit access indicating the direction of travel to the nearest exit and exit discharge. Additionally, the line-of-sight to an exit sign must be visible at all times.
Each doorway or passage along an exit access that could be mistaken for an exit must be marked “Not an Exit” or similar designation, or be identified by a sign indicating its actual use (e.g., closet).
Each exit sign must be illuminated to a surface value of at least five-foot candles (54 lux) by a reliable light source and be distinctive in color. Self-luminous or electroluminescent signs that have a minimum luminance surface value of at least .06-foot-lamberts are permitted.
Each exit sign must have the word “Exit” in plainly legible letters not less than six inches (15.2 centimeters (cm)) high, with the principal strokes of the letters in the word “Exit” not less than 3/4- inch (1.9 cm) wide.
OSHA references its acceptance of the NFPA’s emergency exit requirements under 1910.35, where it states that employers who are following the exit-route provisions of NFPA 101, Life Safety Code, meet OSHA’s requirements. OSHA also acknowledges that those following the International Code Council’s, International Fire Code, satisfy OSHA’s compliance requirements.
NFPA‘s Exit Sign Requirements
Within the 2015 edition of NFPA 101, Life Safety Code, section 7.10. It contains details regarding the placement, visibility, and acceptable forms of illumination for exit signs. NFPA states that any new exit signs must be located so that no point in an exit access corridor is more than the sign’s rated viewing distance or 100-feet, whichever is less, from the nearest sign. Exit signs with directional indicators must be placed in every location where the direction of travel to reach the nearest exit is not apparent.
The NFPA states that every sign must be readily visible and must contrast with the background where it’s placed. “No decorations, furnishings, or equipment that impairs visibility of a sign shall be permitted. No brightly illuminated sign (for other than exit purposes), display, or object in or near the line of vision of the required exit sign that could distract attention from the exit sign shall be permitted.”
Under section 18.104.22.168 of the Life Safety Code, it declares that all exit signs must be illuminated by a reliable light source and must be legible in both normal and emergency exit lighting modes. Section 7.10 breaks illumination into two broad categories: externally illuminated and internally illuminated. Externally illuminated refers to a source of illumination that comes from outside the exit sign while internally illuminated exit signs possess the illumination source inside the sign.
For externally illuminated signs, the Life Safety Code section 22.214.171.124 requires a level of illumination of not less than five-foot candles (54 lux) at the illuminated surface and a contrast ratio of not less than five-tenths.
Internally illuminated signs must be listed under the American National Standards Institute (ANSI)/Underwriters Laboratory (UL) 924, Standard for Emergency Lighting and Power Equipment. The Life Safety Code does allow for three exceptions to this for certain approved existing exit signs (section 126.96.36.199). The exceptions are:
They are approved existing signs.
They are existing signs having the required wording in legible letters not less than four inches (100 millimeters (mm)) high.
They are signs that are under Exit Door Tactile Signage (188.8.131.52) and Floor Proximity Exit Signs (184.108.40.206).
Also under internally illuminated, the Life Safety Code section 220.127.116.11 details the illumination requirements for photoluminescent signs. Photoluminescent is defined as “having the ability to store incident electromagnetic radiation typically from ambient light sources, and release it in the form of visible light.” Photoluminescent signs must be continually illuminated while the building is occupied; the charging illumination must be a reliable light source as determined by the AHJ.
Emergency Lighting Requirements
Also referred to as egress lighting, emergency lighting is designed to illuminate and identify hallways, stairwells, and exits to facilitate a safe and orderly evacuation from a facility. Emergency lighting is generally required in all commercial, industrial, educational, religious, institutional, public housing, medical, and many other facilities whether for-profit or non-profit.
Within the Life Safety Code, the NFPA’s requirements for emergency lighting are referenced under section 7.9. Emergency illumination (when required) must be provided for a minimum of 1.5-hours in the event of failure of normal lighting. The emergency lighting must be positioned to provide initial illumination of not less than an average of one footcandle (10.8-lux) and a minimum at any point of 0.1-footcandle (1.1-lux) measured along the path of egress at floor level. These levels can decline to a minimum of 0.6-footcandle (6.5-lux) average and 0.06-foot-candle (0.65-lux) at any one point at the end of emergency lighting time (1.5-hours). The maximum illumination at any one point can be no more than 40 times the minimum illumination at any one point to prevent excessively bright and dark spots (section 18.104.22.168.3). The emergency lighting system must be positioned to provide illumination automatically in the event of any interruption of normal lighting (section 22.214.171.124).
Testing Requirements for Emergency Lighting
Section 7.9.3, of the Life Safety Code, addresses the NFPA’s requirements for testing of emergency lights. The section acknowledges three different categories of emergency lights: traditional, self-testing/self-diagnostic, and computer-based self-testing/self-diagnostic. It essentially requires both a monthly activation test, where the lights remain illuminated for a minimum of 30-seconds and an annual test where the lights are activated for 1.5-hours to simulate a long-term emergency event.