Qualified persons only. This page is general education, not a procedure. Work on electrical or mechanical equipment only if you are trained, authorized and qualified for that equipment. Follow your employer's written energy-control program under OSHA 29 CFR 1910.147, the electrical safe-work practices in NFPA 70E, and the equipment manufacturer's manual. If you are unsure, stop and ask a qualified person.
What the standard covers
OSHA's standard for the control of hazardous energy (29 CFR 1910.147) covers servicing and maintenance of machines and equipment where unexpected startup or release of stored energy could injure workers. Hazardous energy can be electrical, mechanical, hydraulic, pneumatic, chemical, thermal or other (OSHA).
What employers must have (summary)
- A written energy control program with equipment-specific procedures.
- Training: workers authorized to lock out must know the hazardous energy sources, their type and magnitude, and how to isolate and control them. Everyone working in the area must know not to restart locked or tagged equipment.
- Specific rules and limits for tagout where tags are used instead of locks.
- Retraining when procedures change or proficiency slips.
Summarized from OSHA's Control of Hazardous Energy page. Read the full standard for exact requirements, including periodic inspections.
The typical sequence (general)
- Prepare: know the energy sources from the equipment procedure.
- Notify affected workers.
- Shut down using normal stopping.
- Isolate every energy source.
- Apply your own lock and tag.
- Release or restrain stored energy (capacitors, springs, pressure, gravity).
- Verify isolation: try to start, and test for absence of voltage with a rated meter.
- Do the work. Restore only by the procedure, with everyone clear.
This is a general outline for orientation. Your employer's written procedure for that machine governs.
Free tools that already exist
- HazComFast LOTO procedure generator (third party, free). Review any generated procedure with your safety program.
Sources: 29 CFR 1910.147 (eCFR, verified to sit in Part 1910 Subpart J via the eCFR API on 2026-10-16); OSHA Control of Hazardous Energy; NFPA 70E for electrical safe work practices.