| Purpose of lockout/tagout | The standard protects employees from the unexpected energization, start-up, or release of stored energy during servicing and maintenance. | Keeps the controlling keys and personal locks organized and prevents unauthorized re-energization. | Use a documented energy-control procedure before work begins. | 29 CFR 1910.147(a)(1)(i) |
| Who applies locks | Authorized employees who perform servicing or maintenance must apply lockout or tagout controls. | Provides a central location for personal locks, group lock devices, and control keys. | Assign each authorized employee a uniquely identifiable personal lock. | 29 CFR 1910.147(b), (d) |
| Group maintenance work | When a group performs servicing, each authorized employee must receive equivalent protection through a group lockout or tagout procedure. | Allows multiple workers to attach personal locks while one group device controls the energy-isolating mechanism. | No employee removes their lock until their work is complete and they are clear of the hazard. | 29 CFR 1910.147(f)(3) |
| Energy sources | Hazardous energy may include electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or gravitational energy. | Helps store the locks, tags, hasps, and blocking devices needed for different energy-isolation points. | Identify every energy source and release, restrain, or dissipate stored energy before work. | 29 CFR 1910.147(d)(3) |
| Verification before work | After isolation and lockout, the authorized employee must verify that isolation and de-energization have been accomplished before starting work. | Makes verification tools and required documentation easier to keep together and access. | Test the equipment using an appropriate method, then return controls to the off or neutral position. | 29 CFR 1910.147(d)(6) |
| Lock removal | Each lockout or tagout device must generally be removed by the employee who applied it, subject to a documented employer procedure for exceptional cases. | Reduces the risk of misplaced locks and provides a controlled location for identifying the responsible employee. | Confirm the employee is unavailable, make reasonable efforts to contact them, and inform them before returning to work. | 29 CFR 1910.147(e)(3) |
| Training categories | Authorized, affected, and other employees require training appropriate to their role in the energy-control process. | Supports a consistent system in which workers understand who may apply, remove, or work around locks. | Train authorized employees on energy sources, hazards, procedures, and limitations of tags. | 29 CFR 1910.147(c)(7) |
| Annual inspection | Each energy-control procedure must be inspected at least annually to verify that it is followed and remains adequate. | Provides a practical place to keep inspection records, corrective actions, and procedure-review materials. | Use an authorized employee who is not the employee using the procedure being inspected. | 29 CFR 1910.147(c)(6) |
| Tags versus locks | A tag is a warning device and does not provide the same physical restraint as a lock. Tagout-only systems require additional protective measures where permitted. | Encourages the use of physical locks and controlled group devices instead of relying solely on warning labels. | Use lockout whenever the energy-isolating device can be locked out, unless an exception under the standard applies. | 29 CFR 1910.147(c)(2) |
| Preventable fatality risk | Industry safety materials commonly cite approximately 120 fatalities and many thousands of injuries each year as preventable outcomes associated with hazardous energy. This figure is an estimate used in safety communications, not a single OSHA annual count. | Creates visible accountability and reduces the chance that a worker’s lock or group-control step is skipped. | Treat every unexpected start-up or energy release as a potentially fatal event and stop work when controls are incomplete. | OSHA: Control of Hazardous Energy |