OSHA and the National Fire Protection Association (NFPA) give the general requirements for means of egress. 29 CFR 1910.35 defines a means of egress in this way: “A means of egress is a continuous and unobstructed way of exit travel from any point in a building or structure to a public way and consists of three separate and distinct parts.” They are:
Exit access—that portion which leads to the entrance of an exit.
Exit—that portion which is separated from all other spaces of a building or structure by construction or equipment to provide a protected way of travel to the exit discharge.
Exit discharge—that portion between the termination of an exit and a public way.
OSHA requires that “each exit route be adequately lighted so that an employee with normal vision can see along the exit route”. 1910.37(b)(1).
OSHA also requires that “each exit must be clearly visible and marked by a sign reading “Exit”. 1910.37(b)(2). “Each exit route door must be free of decorations or signs that obscure the visibility of the exit route door.” 1910.37(b)(3). “Each doorway or passage along an exit access that could be mistaken for an exit must be marked “Not An ” or similar designation, or be identifed by a sign indicating its actual use (e.g., closet).” 1910.37(b)(5).
Exit Sign Requirements
Every sign must have the word “Exit” in plainly legible letters not less than six inches high, with the principal stroke of the letter .75 inches wide (29 CFR 1910.37(b)(7)). (See NFPA 101 7.10 for further specifications.) Where the direction of travel to the nearest exit is not immediately apparent, an exit sign or similar designation with an arrow indicating the direction to the exit is required (29 CFR 1910.37(b)(4)).
Infographic provided by emedco, see more here: http://www.emedco.com
OSHA Exit information can be found by downloading this informative PDF file