The intricacies of EXIT signs
An “Exit” sign works to visually identify a doorway or passage along an exit access that leads to an exit. Similarly, a sign that reads “Not an Exit” is used to identify a doorway or passage along an exit access that could be mistaken for an exit. Along with other details surrounding color and lettering, it’s important to read further into the regulations to understand what OSHA requires.
Location
Location
You’ll want to place an exit sign wherever it is appropriate along the exit access. As defined in 1910.34, the “exit access” means that portion of an exit route that leads to an exit. An example of an exit access is a corridor on the fifth floor of an office building that leads to a two-hour fire resistance-rated enclosed stairway.
Identifying exits along an exit access does not necessarily mean that every door along a corridor or hallway should be identified as an exit if it is in fact not an exit. As stated in 1910.37(b)(5), OSHA further explains that 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).
Color
There has been some confusion over the years as to whether EXIT signs must be a particular color, for instance red or green. In a September 1972 letter of interpretation, OSHA clarified that any color, or color combination, that is readily visible or distinctive in appearance is acceptable. Keep in mind that local building codes may require a certain color, but OSHA standards do not.
Lettering
As stated in 1910.37(b)(7), OSHA requires exit signs to be not less than six inches high, with the principal strokes of the letters in the word “Exit” not less than three-fourths of an inch. There is, however, an exception to this rule, as per a July 1986 letter of interpretation. It states that, for any existing externally illuminated exit signs, having the word “Exit” in plainly visible letters not less than 4 ½ inches high in existing buildings, other than in places of assembly, may be continued in use.
Before you spend money on “Exit” and “Not an exit” signage, remember that these regulations leave open some subjectivity for interpretation. Be sure to review your facility emergency action plan, look at your designated evacuation routes, and take a walk along all routes that lead to an exit, to see what signs currently exist. Not every door or passage will be along an exit access, and not every door or passage will have the potential to be mistaken for an exit.