The standard covers all employers except construction, agriculture, maritime, electrical utilities, and gas/oil well drilling, whose needs are addressed within specific sections of the OSHA regulations.

The need for the standard is apparent when considering some facts surrounding one documented OSHA case of an office worker who experienced a jam in an office shredding machine. The worker traced the shredder's power cord to an electrical outlet in an adjacent room, unplugged it, and returned to clear the jammed shredder. While the worker was in the process of clearing the jam, another worker happened by, noticed the plug out of the outlet, and promptly reinserted it. The shredder started up and severed the fingers of the office worker's hand.

A common interpretation of the standard considers it only within the context of electrical energy. The standard does include electrical equipment, but also includes any other equipment or devices which can accidentally or unexpectedly release energy while the equipment or device is being serviced or repaired. Any machine or device that can store residual energy, such as electrical, mechanical, hydraulic, pneumatic, chemical or thermal, is a candidate for lockout/tagout if sudden and unexpected release of that energy could constitute a hazard to workers.

Consider a situation where the automatic door opener for an overhead garage door is malfunctioning and is being replaced. The door is open, in the overhead position, and spring loaded to go down as well as to assist in opening manually. The tension on the spring is mechanical energy that could cause the door to close unexpectedly and, consequently, must be locked out to prevent accidental closing. Actually, gravity alone in this case, without benefit of the spring under tension, would constitute a hazard and be covered under the Lockout/Tagout Standard.