OSHA defines an exit route as a continuous, unobstructed path from any place in a workplace to a safe location and exit . An exit consists of an exit access, the exit itself and the exit discharge. Exit access is the part of the exit route that leads to the exit. The exit is the portion of the exit route away from other parts of the building that offers a protected path to the exit discharge. The exit discharge is defined as the final part of the exit route that leads to the outside or other safe area.
OSHA requires workplaces to have a minimum of two emergency exit routes. However, large workplaces or buildings with a large number of employees are required to have additional exits. OSHA requires that exit routes form a permanent part of the building and that the exit discharge be large enough to accommodate the number of people in the building. Stairs that are part of an exit route are required to have doors or a partition that indicates the direction of the path to the exit discharge. Exit route doors are required to remain unlocked from the inside and any device attached to the door cannot interfere with the use of the door if it fails.
Doors to rooms designed to hold fire hazards or more than 50 people built along the exit route are required to use side-mounted hinges that open with the path of travel toward the exit. OSHA also requires that parts of a building designated as an exit route be large enough for the maximum load of occupants on that floor. Exit routes are required to have ceiling heights that measure at least seven feet six inches high and access points to the exit route must have a uniform width of at least 28 inches.
Outdoor exit routes are required to maintain the same requirements for size and continuity that regulate indoor exit routes. In addition to the usual requirements, outdoor exit routes must provide guard rails if there is a falling hazard along the route and provide a covering to prevent the accumulation of snow and ice. Outdoor exit routes are required to have straight, solid, smooth paths; any dead ends along the route can extend no longer than 20 feet.
OSHA specifically requires the separation of fire exits from the workplace using fire-resistant materials. Exits in buildings of less than three stories must use materials rated for one hour of fire resistance. Exits in larger buildings must use materials rated for at least two hours of fire resistance. Exits are only allowed to have the openings necessary to provide the building's occupants with access to the exit from the workplace. OSHA also requires employers to cover emergency exits with a self-closing fire door that either remains closed or closes automatically in the event of an emergency.