Hands-on maintenance of a drive, conveyor or motor calls for more than stopping its normal operation. OSHA's hazardous-energy standard addresses servicing and maintenance where unexpected energization, startup or release of stored energy could injure employees. An equipment-specific energy-control procedure connects the work being done to the energy sources that must be controlled.
OSHA's hazardous-energy overview identifies electrical, mechanical, hydraulic, pneumatic, chemical and thermal sources, among others. Its examples include a jammed conveyor suddenly releasing, a steam valve turning on during downstream repairs, and internal equipment wiring shorting during maintenance. The conveyor example is especially relevant when clearing a jam appears to be a quick task.
The question is whether energy can reach the person doing the work, including energy left in the equipment after shutdown. Identify that possibility before treating the machine as ready for service. A stopped drive and a drive whose hazardous energy has been isolated and verified are different conditions; the procedure needs to address the latter.
29 CFR 1910.147 defines an energy isolating device as a mechanical device that physically prevents energy transmission or release. Examples include a manually operated electrical circuit breaker and a disconnect switch. Lockout places a device on the isolating device so that it and the controlled equipment cannot be operated until the lockout device is removed.
Tagout places a warning device on an energy isolating device to indicate that operation is prohibited until the tag is removed. OSHA says tags do not provide the physical restraint supplied by a lock. Where the isolating device can be locked out, the employer's program must use lockout unless it demonstrates that a tagout system provides full employee protection under the standard.
After January 2, 1990, new equipment installations and replacement, major repair, renovation or modification of equipment must have energy isolating devices designed to accept a lockout device. This requirement concerns the isolating devices, so checking only whether a warning tag can be attached does not answer the same question.
The sequence in OSHA's energy-control requirements begins before shutdown and ends with verification before servicing starts. Each stage serves a distinct purpose:
Use this sequence to understand the written procedure for the equipment, rather than guessing at isolation points from a general description. Shutdown is one stage in the sequence; it does not replace stored-energy control or verification. The standard also states that each lockout or tagout device is to be removed by the employee who applied it.
The standard lists locks, tags, chains, wedges, key blocks, adapter pins, self-locking fasteners and other hardware provided by the employer to isolate, secure or block equipment from energy sources. It requires devices to be standardized within the facility by at least one of color, shape or size; tagout devices also need standardized print and format.
Lockout devices must be substantial enough to resist removal without excessive force or unusual techniques, such as bolt cutters or other metal cutting tools. A hardware list is only part of the program. The procedure still needs to connect the device to the energy isolating point and to the work that requires isolation.
OSHA requires a periodic inspection of the energy-control procedure at least annually to ensure that the procedure and the standard are followed. This is an inspection of the energy-control procedure, distinct from checking a belt or chain for wear. Keep the two purposes clear when planning maintenance activities.
OSHA's overview also requires worker training in the purpose and function of the program and in safe application, use and removal of energy-control devices. Employees working in areas where the procedures are used need instruction in their purpose and use, especially the prohibition on attempting to restart or reenergize locked-out or tagged-out equipment.
OSHA's preliminary FY2026 top-10 most-cited standards rank lockout/tagout #3, powered industrial trucks #7 and machine guarding #10. These are preliminary ranks, not violation counts or a measure of the conditions at any particular facility.
The maximum penalties OSHA lists for assessments after Jan. 15, 2026 are $16,550 per serious violation and $165,514 per willful or repeated violation. Maximums do not predict a particular assessment. For maintenance planning, the practical focus remains the procedure: identify the energy, isolate it, control what remains stored and verify before work begins.