The Occupational Safety and Health Association (OSHA) outlines requirements for safe workplaces to protect employees. OSHA is part of the U.S. Department of Labor. Aisles are highly trafficked walking areas and important safety escape routes, and the OSHA aisle requirements help keep them free of obstruction and require employers to mark them adequately.
TL;DR (Too Long; Didn't Read)
If the aisle is an emergency exit route, it must be at least 28 inches wide and 7 feet, 6 inches high.
Clean and Clear
To ensure safe walking space, the OSHA requires that all floors be kept clean and free from holes, nails, splinters and loose boards on the ground. This rule includes passageway floors, including aisles. Aisles should be free of obstructions and should have safe clearances so that people can easily get through them for everyday use and in case of emergency evacuations. If an aisle is an emergency exit route, you cannot have any obstruction blocking it, nor anything attached to the ceiling that comes to a point less than six feet eight inches from the ground.
Width and Height
Specific aisle requirements are made for industrial aisles. In terms of width, industrial aisles should be at least 4 feet and at least 3 feet wider than the largest equipment that has to pass through them. In offices, minimum height and width requirements apply to emergency exit aisles. As a general rule, you'll need aisles of sufficient width to allow the safe evacuation of all the people who work on the floor served by the aisle. The minimum requirement is 28 inches wide and 7 feet, 6 inches high.
OSHA suggests that permanent aisles and passageways have markings to show where aisle space is. Aisles in industrial operations should have markings in the form of lines that define the aisle space. The lines can be any clearly visible color and should be between 2 and 6 inches wide. Employers do not have to use continuous lines; they can also use dotted lines or strip lines as long as they are easily visible.
Grocery Warehousing Aisles
Grocery warehouse aisles need large enough widths for employees to carry items off their shelves safely. If aisles are too narrow, employees may try to carry heavier loads and take longer alternate aisle routes to avoid congestion in an area. Heavy loads can pose a health risk for employees, such as back problems. Therefore, the OSHA suggests making aisles extra wide in highly trafficked areas.
According to OSHA safety guidelines, any wall openings, including wall openings in aisles, that lead to a drop of more than 4 feet should have a rail, picket fence, roller, half door or similar barrier. Employers need to make sure to have manhole covers over all unattended manholes, hinged floor coverings over chutes and hatchways, rails or attendants near temporary floor openings, railings near stairway floor openings and floor covers over trapdoor openings. OSHA requires covers over or guardrails near open pits, tanks, vats, ditches and other similar hazards. This rule applies to aisles near these hazards.