So in my previous post, we covered the SIZE of the EXIT signs and in this post, I want to cover the “illumination” requirements of these EXIT signs. Simply stated, OSHA and the IBC require the face of the sign to be illuminated to at least 5-foot candles or 54 Lux at ALL TIMES. Which is NOT a lot of light. Of course, when the area has its normal lights on, meeting this illumination requirement is usually very easy. But at night time inside a building when the lights go out, we will be far less than 5-foot candles or 54 Lux. So the question I always get is “when do I need self-illuminating signs?”
Here is the answer…
If you’d like a visual on what the foot-candles and LUX brightnesses are, here is what I like to refer people to: https://lightpolesplus.com/foot-candle-reference-guide/
This is NOT an endorsement of these products – I just like their visual display showing the different light levels that most of us can relate to.
First and foremost you do NOT need to use self-illuminated EXIT signs to comply with OSHA. You MAY NEED this type of sign to comply with your local building and fire codes which are usually MUCH MORE up-to-date than OSHA’s Egress standards.
It is perfectly acceptable to have EXTERNAL emergency lighting that will illuminate the face of your EXIT signs to at least 5-foot candles or 54 Lux. But we MUST ensure these emergency lights maintain their directional illumination, meaning that each month when we do our inspections, part of the inspection is that the lights are properly positioned in order to light up the EXIT signs.
| 1910.37(b)(6) 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 footlamberts (0.21 cd/m2) are permitted. |
Building Codes (some may differ slightly) will require the following: (emphasis by me)
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1013.3 Illumination Exit signs shall be internally or externally illuminated. Exception: Tactile signs required by Section 1013.4 need not be provided with illumination. … 1013.5 INTERNALLY Illuminated Exit Signs Electrically powered, self-luminous and photoluminescent exit signs shall be listed and labeled in accordance with UL 924 and shall be installed in accordance with the manufacturer’s instructions and Chapter 27. Exit signs shall be illuminated at all times. … 1013.6 EXTERNALLY Illuminated Exit Signs Externally illuminated exit signs shall comply with Sections 1013.6.1 through 1013.6.3. 1013.6.1 Graphics Every exit sign and directional exit sign shall have plainly legible letters not less than 6 inches (152 mm) high with the principal strokes of the letters not less than 3/4 inch (19.1 mm) wide. The word “EXIT” shall have letters having a width not less than 2 inches (51 mm) wide, except the letter “I,” and the minimum spacing between letters shall be not less than 3/8 inch (9.5 mm). Signs larger than the minimum established in this section shall have letter widths, strokes and spacing in proportion to their height. The word “EXIT” shall be in high contrast with the background and shall be clearly discernible when the means of exit sign illumination is or is not energized. If a chevron directional indicator is provided as part of the exit sign, the construction shall be such that the direction of the chevron directional indicator cannot be readily changed. 1013.6.2 Exit Sign Illumination The face of an exit sign illuminated from an EXTERNAL SOURCE shall have an intensity of NOT LESS THAN 5 footcandles (54 lux). 1013.6.3 Power Source Exit signs shall be illuminated at ALL TIMES. To ensure continued illumination for a duration of not less than 90 MINUTES in case of primary power loss, the sign illumination means shall be connected to an emergency power system provided from storage batteries, unit equipment or an on-site generator. The installation of the emergency power system shall be in accordance with Chapter 27. Exceptions:
NOTE: I-2 is “Institutional” occupancies, such as hospitals and care facilities. |