Most lockout/tagout training covers one worker locking out one machine. Real maintenance rarely looks like that: a press rebuild pulls in millwrights, electricians, and a contractor crew, all with hands in the same equipment at the same time. Group lockout/tagout is OSHA’s answer to that situation — a defined method that gives every worker in the group the same level of protection they would have working alone.
Done correctly, group lockout is straightforward: one authorized employee coordinates the isolation, a group lockbox holds the keys, and every worker applies a personal lock. Done casually — one lock for the whole crew, keys in a supervisor’s pocket — it is one of the fastest routes to a willful citation and a fatality. This guide covers the compliant method end to end.
When group lockout applies
Group lockout applies whenever servicing or maintenance on a machine exposes more than one authorized employee to hazardous energy at the same time — a multi-craft rebuild, a crew clearing a major jam across zones, or a contractor team working alongside your own techs. If two or more people depend on the same isolation, you need a group procedure, not two solo procedures run in parallel.
Your written energy control program must spell out the group method in advance. Improvising coordination on the day — "I’ll hold the keys, you all get to work" — is exactly the failure mode the standard’s group provisions exist to prevent.
The primary authorized employee: the coordinator role
Every group lockout designates one primary authorized employee with overall responsibility for the isolation. This person applies the locks to each energy-isolating device (or supervises their application), verifies zero energy for the group, and controls when the equipment may be re-energized. The role is coordination, not trusteeship of other people’s safety: the primary employee’s verification does not replace any individual’s right to their own lock.
Choose the primary employee for competence with the specific equipment, not seniority alone. They must know every energy source on the machine and the full isolation sequence — because the group’s protection is only as complete as the primary employee’s isolation.
The group lockbox method, step by step
The lockbox (also called a group lock box or lockout station box) is the standard compliant method. The sequence runs:
- The primary authorized employee isolates every energy source per the machine-specific procedure and applies the equipment locks.
- The keys to those equipment locks go inside the group lockbox — never in a pocket, on a hook, or in an office.
- Every authorized employee in the group applies a personal lock (and tag) to the lockbox before starting work. No personal lock, no work — no exceptions for "I’m only helping for five minutes."
- Each worker verifies protection for themselves: confirm their lock is on the box and understand the isolation that protects them.
- Work proceeds. As each worker finishes, only that worker removes their own lock from the box.
- When the last personal lock comes off and the primary employee confirms all personnel and tools are clear, the box is opened, equipment locks are removed by the primary employee, and the machine is returned to service per the restart sequence.
The personal-lock rule is absolute
The single non-negotiable of group lockout: every exposed worker applies and removes only their own lock. A supervisor’s lock does not cover a crew. A contractor foreman’s lock does not cover the contractor’s helpers. Each lock represents one person’s life, and only that person controls it.
Two related rules complete the picture. Locks are never removed by anyone except the employee who applied them, other than through the documented emergency-removal procedure (which requires verifying the employee is off site). And multi-hasp adapters or hasps on the equipment locks let several personal locks share one isolation point when a lockbox is impractical for small jobs — the principle is identical: one lock per person.
Shift changes and personnel turnover mid-job
Long jobs outlast shifts, so the program must define how protection transfers without a gap. The compliant pattern is overlap, never handoff-by-trust: arriving employees apply their personal locks to the box before departing employees remove theirs. At no point is the box — and therefore the equipment — without a lock representing every exposed worker.
Document the exchange: who arrived, who left, and when. For multi-day outages, the primary-employee role itself may rotate; the transfer of that role needs the same explicit, recorded handover as the locks.
The failures inspectors actually find
Group lockout citations follow a depressingly consistent script. Watch for these in your own program:
- One lock for the crew — a supervisor locks out and everyone else works under it with no personal locks.
- Keys outside the box — equipment keys carried by the primary employee or left in the maintenance shop, defeating the entire method.
- Helpers and contractors skipped — "they’re just holding the light" still counts as exposure if they’re inside the hazard zone.
- No designated primary employee — isolation performed ad hoc by whoever arrived first, with nobody accountable for the full sequence.
- Restart before the box is clear — equipment locks removed while a personal lock is still on the box, or while a worker is still in the cell.
- No written group procedure — the method exists as tribal knowledge, so every crew invents its own version.
One lock per person — no exceptions. Follow Tegis on Google for more crew-safety procedures.
Key takeaways
- Group lockout needs a written method before the job, not coordination invented on the day.
- One primary authorized employee owns the isolation sequence for the group.
- Equipment-lock keys go in the group lockbox; every exposed worker adds a personal lock.
- One lock per person, removed only by its owner — no crew coverage, no exceptions for helpers.
- Shift changes transfer protection by overlap: incoming locks on before outgoing locks off.
Frequently asked questions
Can one lock cover an entire crew during servicing?
No. Every authorized employee exposed to the hazard must apply a personal lock — to the equipment, a hasp, or the group lockbox. A single supervisor’s lock covering a crew is one of the most commonly cited group-lockout failures and removes each worker’s individual control over their own protection.
What does the primary authorized employee actually do?
The primary authorized employee coordinates the group isolation: they ensure every energy source is isolated per the machine-specific procedure, verify zero energy, place the equipment-lock keys in the group lockbox, and control the return-to-service sequence. They do not substitute for anyone’s personal lock.
Do contractors join the group lockbox or run their own lockout?
Either method works if it is planned and documented — contractors commonly add personal locks to the host’s group lockbox after the required two-way LOTO briefing under 1910.147(f)(2). What fails audits is the unplanned middle: contractors working in the cell with no locks at all because "the host has it covered."
Hasp or lockbox — which should we use?
Both satisfy the one-lock-per-person rule. A hasp (multi-lock adapter) on the equipment disconnect works for small crews at a single isolation point. A group lockbox scales better: multiple isolation points, large crews, contractors, and multi-shift jobs. Most mature programs standardize on the lockbox and keep hasps for simple two-person jobs.
Can the primary employee also do hands-on work?
Yes. The primary employee coordinates the isolation, but they are also an authorized employee exposed to the hazard — so they apply their own personal lock to the group lockbox like everyone else. Coordination and protection are separate; the primary employee does not get an exception to the personal-lock rule.