OSHA regulates hallway width to keep exit routes clear and usable in case of an emergency. Since this is the motive behind the OSHA regulations, documentation often refers to the hallway as an exit access. Hallway width requirements include a 28-inch minimum, adjustment for occupancy, allowance for objects in the hallway, override of other mandates and subjection to mandates from other agencies.
OSHA standard 1910.36 says that a hallway that is used to access an exit must be at least 28 inches wide at all points.
Adjustment for Occupancy
After setting the 28-inch minimum, standard 1910.36 later says that the exit route width must take into account the maximum number of people who might need to use the hallway at once. This number is based on the maximum occupancy allowed on each floor served by the hallway.
Allowance for Objects
Hallways must be wider than 28 inches if they contain furniture or equipment. If any items are housed in the hallway (or project into the hallway from another room), they must not diminish the width at any point to less than 28 inches.
Other OSHA Mandates
OSHA hallway width requirements override some other OSHA mandates, even within the same subpart. Standard 1910.24 states that stairways must be at least 22 inches wide, but standard 1910.36 overrides that requirement when stairways are part of the hallway that is an exit route. Exit hallway stairs must also be 28 inches wide.
Other Agency Mandates
OSHA requirements can be overridden by stricter mandates from other agencies. The Americans with Disabilities Act (ADA) mandates a 44-inch hallway width for wheelchair access.