Short answer. On US construction sites, lockout and tagging of electrical circuits is covered by OSHA 29 CFR 1926.417, and NFPA 70E-2024 Article 120 describes how to establish an electrically safe work condition. OSHA 1910.147 is the general-industry lockout/tagout standard.
Definition. Lockout/tagout (LOTO) is the set of practices that control hazardous energy: workers isolate energy sources and place locks and tags on energy-isolating devices so the equipment cannot be energized while people work on it.
Which rules apply where
| Rule | Where it applies | What it covers, in plain words |
|---|---|---|
| OSHA 29 CFR 1926.417 | Construction (Subpart K) | Lockout and tagging of electrical circuits that are deactivated for work. |
| OSHA 29 CFR 1910.147 | General industry | Control of hazardous energy during servicing and maintenance. Its scope excludes construction, and electrical work on or near conductors in utilization installations is covered by Subpart S (1910.331–1910.335). |
| OSHA 29 CFR 1910.333 | General industry electrical work | Electrical safety work practices, including lockout and tagging of circuits (1910.333(b)(2)). |
| NFPA 70E-2024, Article 120 | Consensus standard used by employers | How to establish and verify an electrically safe work condition. |
Establishing an electrically safe work condition (NFPA 70E-2024, 120.6)
In plain English, the process is:
- Find all possible sources of electrical supply, using up-to-date drawings, diagrams and labels.
- Interrupt the load current, then open the disconnecting devices for each source.
- Where possible, visually verify that all blades of the disconnects are fully open or that drawout breakers are withdrawn.
- Release stored electrical energy.
- Release or block stored non-electrical energy.
- Apply locks and tags under a documented, established procedure.
- Test for absence of voltage at each point of work, with a properly rated meter checked on a known source before and after the test.
- Where there is a possibility of induced voltage or stored energy, ground the phase conductors or circuit parts as required.
Roles: qualified, authorized and affected people
- Qualified person. Has the skills, knowledge and safety training for the equipment and its hazards.
- Authorized person. Applies the locks and tags and is responsible for the lockout on the equipment (OSHA: “authorized employee”).
- Affected workers. Work in the area or on the equipment, and must know that it is locked out and must not be re-energized.
Group lockout and the group lockbox
When several workers share the same isolation, many programs use a group lockout. The authorized person locks out the isolation points and places the keys in a group lockbox. Each worker then attaches a personal lock to the group lockbox. Nothing can be re-energized until the last personal lock comes off. When one worker’s lock is used directly on a single device by several people, the device is a lockout hasp (multi-lock hasp).
Abandoned personal locks. A personal lock can be left on a group lockbox after its owner has left the site (for example, they quit, were let go or were injured). That lock blocks re-energization for everyone else, and it must be removed only under your energy-control program’s removal procedure, never by cutting it off informally.
Shift changes
Lockout protection must carry over from one shift to the next without a gap. Your program should say how locks are transferred between outgoing and incoming workers, and how the handover is recorded.
Paper and electronic LOTO records
Whatever the format, a LOTO record should show who applied each lock, which lock, at which isolation point, when, the verification-of-zero-energy result, and who removed it and when. Paper records are simple and need no device. Electronic records can add time stamps, photos of each lock and tag, and a fixed step order, and they can be reviewed at HQ after sync. Either can be done well or badly; the program and the people matter most.
Where ICARUS Ops fits
The ICARUS Ops Error Elimination System (EES) includes electronic lockout/tagout. Each isolation point appears in a fixed order, crews take a photo of each lock and tag, a required step records verification of zero energy, and the authorized person signs off before work continues. EES runs in the native Android and iOS apps with no signal, with an integrated abandoned lock protocol for personal locks left on a group lockbox. See electronic LOTO.
EES supports, and does not replace, your OSHA 1910.147, 29 CFR 1926.417 and NFPA 70E energy-control program.
See a sample ICARUS Ops EES procedure
See a sample ICARUS Ops EES procedure
Demos are for teams actively evaluating software for deployment.
Frequently asked questions
Does OSHA 1910.147 apply to construction?
OSHA 29 CFR 1910.147 is the general-industry lockout/tagout standard, and its scope excludes construction work. On US construction sites, lockout and tagging of electrical circuits is covered by 29 CFR 1926.417.
Does electronic LOTO replace physical locks?
No. Crews still apply physical locks and tags under the energy-control program. An electronic LOTO procedure guides the steps and keeps the record: who applied which lock, at which point, when, and the verification result.
What is verification of zero energy?
It is the step where a qualified person confirms that the equipment is de-energized before work starts, for example by testing for absence of voltage with a meter checked on a known source before and after the test.
What is a group lockbox?
In a group lockout, the authorized person locks out the isolation points and places the keys in a group lockbox. Each worker then puts a personal lock on the box, so the equipment cannot be re-energized until the last worker removes their lock.