I have not found an exact aisle space but it needs to be adequate to allow easy access and not cause harm to employees. Here is what I use when items are blocked. Also you may want to look into access to emergency equipment.
NFPA 10, Portable Fire Extinguishers, specifies floor clearance and mounting heights, based on the extinguisher weight, as follows:
1. Extinguishers with a gross weight not exceeding 40 LB should be installed so that the top of the extinguisher is not more then 5 ft above the floor.
2. Extinguishers with a gross weight greater than 40 LB, except wheeled types, should be installed so that the top is not more than 3-? ft above the floor.
3. In no case can the clearance between the bottom of the extinguisher and floor be less than 4 inches.
Ensure that the fire extinguishers are in place and maintained. OSHA 29 CFR.1910.157 states: ? The employer shall provide portable fire extinguishers and shall mount, locate and identify them so that they are readily accessible to employees without subjecting the employee to possible injury.
The employer shall ensure that the portable fire extinguishers are maintained in a fully charged and operable condition and kept in their designated places at all times except during use?.
