The article doesn’t say, but it emphasized to me why it is prohibited to use an electrical room for storage. Obviously storage impinges on working space, but additionally it creates foot traffic from people who have no business being in there.
2018 IFC
315.3.3 Equipment rooms. Combustible material shall
not be stored in boiler rooms, mechanical rooms, electrical
equipment rooms or in fire command centers as specified
in Section 508.1.5.
Unfortunately avoiding or not being attune to the rules occur. Electrical room mean electrical equipment only. (A room or space in a building dedicated to electrical equipment)
Section 1910.303(g)(1)(ii) elaborates on the clear spaces requirement for such working spaces. Additionally, the working space clearances required by this subpart may not be used for storage. This access and working space shall be kept clear at all times for operation and maintenance personnel and may not be used for intermittent/incidental storage of nonpermanent equipment or furniture, which could interfere with ready access to the electric equipment in the event of an emergency.
NFPA 70, the space required for an electrical room must be ‘equal to the width and depth of the equipment’, extending from the floor to a height of 1.8 m (6 ft) above the equipment or to the structural ceiling, whichever is lower.