Signs bearing the word "EXIT" in plain legible letters shall be placed at exits. If the exit or way to reach the exit is not immediately visable to the clients, access to exits shall be marked with readily visible signs indicating the direction of travel. Exit sign letters shall be at least 6 inches in height with the principal strokes of letters not less than 3/4 inch wide. There shall be tactile exit markings if one or more visually impaired clients are served.
55 Pa. Code § 2390.86