What Lockout/Tagout Is

Control of hazardous energy under OSHA 29 CFR 1910.147 means isolating machines from energy sources and securing those isolation points so they cannot be re-energized while someone is exposed. Energy is not only electrical — hydraulic pressure, compressed air, gravity, springs, heat, and chemicals all count when they can do work.

Lockout uses a lock that physically prevents an energy-isolating device from being moved to the unsafe position. Tagout uses a warning tag that forbids operation but does not by itself provide the same physical restraint. Use the interactive LOTO Safety Checklist as you walk a job, and read Lockout vs Tagout when you need the feasibility distinction.

The Six Standard LOTO Steps

1. Notify affected employees — tell operators and nearby workers that LOTO is starting, why, and how long it should last.
2. Shut down — stop the equipment with the normal orderly shutdown sequence.
3. Isolate energy sources — open disconnects, close valves, block mechanical motion, and address every source on the machine-specific procedure (electrical, mechanical, hydraulic, pneumatic, thermal, chemical).
4. Apply lockout/tagout devices — company-issued locks and danger tags at each isolation point; group lockout when more than one authorized employee is exposed.
5. Relieve or restrain stored energy — bleed pressure, discharge capacitors, block gravity loads, cool hot surfaces, drain process lines as required.
6. Verify zero energy — try to operate the equipment (tryout) and use required meters so you prove the machine will not start before you begin work.

When LOTO Is Required

LOTO applies when employees perform servicing or maintenance where unexpected energization, startup, or release of stored energy could cause injury. Typical shop triggers: changing tooling on a press brake, clearing a jam on a conveyor, repairing a plasma table drive, working inside a compressor cabinet, or opening a hydraulic power unit.

Normal production operations that are routine, repetitive, and integral to production may use alternative measures under the standard’s exceptions — but “we do this every day” is not an automatic free pass. If your body is exposed to hazardous energy during the task, treat LOTO as required until a competent person and written program say otherwise.

Who Is Authorized to Perform LOTO

• Authorized employee — trained to lock out or tag out machines in order to perform servicing or maintenance. Only authorized employees apply and remove their locks/tags (except under documented group or shift-transfer procedures).
• Affected employee — operates or uses a machine that is locked/tagged out, or works in an area where LOTO is performed. Affected employees must be notified but do not apply LOTO devices unless they are also authorized.
• Other employees — anyone who may be in the area; they must understand not to restart or remove devices.

Training, periodic inspections, and machine-specific procedures are program requirements — not paperwork theater. Pair LOTO with process PPE from the PPE Selection Guide and hot-work controls from the Hot Work Permit Checklist when welding or cutting is part of the repair.

Frequently Asked Questions

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