Exit sign requirements (OSHA and NFPA 101)
Where exit signs go, how big and bright they must be, and how they are tested under OSHA and the Life Safety Code.
OSHA exit sign requirements
For workplaces, OSHA's exit route standard (29 CFR 1910.37) requires that each exit be clearly visible and marked by a sign reading "Exit". Key points:
- Exit signs must be illuminated to a surface value of at least five foot-candles by a reliable light source and be distinctive in color.
- The word "Exit" must be in plainly legible letters at least six inches high, with principal letter strokes at least three-fourths of an inch wide. Self-luminous or electroluminescent signs with a minimum luminance of .06 footlamberts are also permitted.
- Doors or passages that could be mistaken for an exit must be marked "Not an Exit" or with their actual use.
- Where the direction to the nearest exit is not immediately apparent, signs must indicate the direction of travel.
NFPA 101 exit sign requirements
The Life Safety Code adds detail on marking the means of egress:
- Exits must be marked by approved, readily visible signs, and the path to them marked where the way to reach an exit is not apparent.
- Signs are generally placed so no point in an exit access corridor is more than 100 feet (or the listed viewing distance of the sign) from the nearest visible sign.
- Internally illuminated signs must be listed (in practice, to UL 924).
- Signs required to be illuminated must stay illuminated during a power failure for at least 90 minutes, which is why exit signs carry battery backup.
- Illuminated exit signs are tested on the same 30-day and annual schedule as emergency lighting.
Exit sign placement in practice
- Over every exit door serving the space.
- At every change of direction in a corridor, with arrows.
- Along long corridors so a sign is always within view, typically within 100 feet.
- Visible from the path of travel, not blocked by doors, displays or signage.
Color
Federal rules do not mandate red or green. Most jurisdictions accept either; some local codes specify one. See red vs green exit signs.
Testing
Battery-backed exit signs need a 30-second test every 30 days and a 90-minute test every year. See how to test exit signs.
Frequently asked questions
What size do exit sign letters have to be?
Under OSHA, at least six inches high with principal strokes at least three-fourths of an inch wide.
Do exit signs need battery backup?
Illuminated exit signs must stay lit for at least 90 minutes during a power failure. Unless the building has an emergency generator or central battery system serving them, that means a built-in battery.
How far apart should exit signs be?
Generally close enough that no point in an exit access corridor is more than 100 feet, or the sign's listed viewing distance, from the nearest visible sign. Confirm with your AHJ.