Lockout/Tagout (LOTO) Practice Test: 18 Questions with Answers

1. What does OSHA’s lockout/tagout standard, 1910.147, actually cover?

Answer: General industry — it explicitly excludes construction, agriculture and maritime, which have their own rules

Construction, agriculture and maritime employment are excluded from 1910.147 by its own scope section — they are covered by other standards. It also does not apply to cord-and-plug equipment unplugged under the exclusive control of the employee doing the work, or to certain hot-tap operations.

Source: OSHA 29 CFR 1910.147(a)(1)(ii), (a)(2)

2. What is an "energy-isolating device" under the standard?

Answer: A mechanical device that physically prevents the transmission or release of energy — a circuit breaker, disconnect switch, line valve or similar block

The device has to physically block energy, not just interrupt a control circuit. A control-circuit device, like a push-button that stops a motor, is specifically not an energy-isolating device.

Source: OSHA 29 CFR 1910.147(b) — definitions

3. Which best describes an "authorized employee" under 1910.147?

Answer: The person who locks out or tags out a machine to perform the servicing or maintenance

An authorized employee is the one performing the service or maintenance and applying the lockout/tagout device. An "affected employee" is someone whose job requires operating the equipment, or working in an area where the servicing is being done — they do not do the locking out themselves.

Source: OSHA 29 CFR 1910.147(b) — definitions

4. After the energy-isolating devices are located and operated to isolate the machine, what must happen before work begins?

Answer: Any hazardous stored or residual energy (springs, capacitors, elevated parts, pressure) must be relieved, disconnected, restrained or otherwise rendered safe

Isolating the source does not get rid of energy already stored in the system. A spring under tension or a raised component still needs to be blocked or bled off before anyone works on the machine.

Source: OSHA 29 CFR 1910.147(d)(5)

5. Right before starting work, how must the authorized employee verify the machine is actually isolated?

Answer: Operate the normal operating controls, or otherwise test the machine, to make sure it will not run — after confirming no one is exposed — then return controls to neutral

A lock proves a device is in place, not that the energy is actually gone. Verification means attempting to operate the equipment (safely, with no one exposed) and confirming nothing happens.

Source: OSHA 29 CFR 1910.147(d)(6)

6. How often must the energy control procedure itself be inspected, and by whom?

Answer: At least annually, by an authorized employee other than the one(s) using the procedure being inspected

The periodic inspection checks that the written procedure is actually being followed and corrects any deviations. It has to be done by someone other than the employee who normally uses that particular procedure, and the employer must certify the inspection — machine, date, employees involved, inspector.

Source: OSHA 29 CFR 1910.147(c)(6)

7. What training do "affected employees" — who do not do the lockout themselves — need under 1910.147?

Answer: Instruction in the purpose and use of the energy control procedure, and the prohibition on trying to restart or re-energize locked-out equipment

Affected employees need to understand why the machine is locked out and that they must never attempt to start it. Authorized employees get the deeper training — recognizing hazardous energy sources, their type and magnitude, and the methods to isolate and control them.

Source: OSHA 29 CFR 1910.147(c)(7)(ii)

8. Which of these would trigger retraining under the standard?

Answer: The employee’s job assignment changes, a new hazard is introduced, or a periodic inspection turns up a deviation from the procedure

Retraining is event-driven, not purely calendar-driven: a change in job duties or machines, a newly introduced hazard, or evidence that the procedure is not being followed correctly all require it.

Source: OSHA 29 CFR 1910.147(c)(7)(iii)

9. Why does OSHA treat a tag, by itself, as weaker protection than a lock?

Answer: A tag is a warning device only — it has no physical ability to restrain anyone from operating the equipment

Training must cover the limitations of tags: they can be removed without authorization, defeated, or simply not seen. A lock physically prevents operation; a tag only warns.

Source: OSHA 29 CFR 1910.147(c)(7)(ii) — tagout system limitations

10. The authorized employee who locked out a machine has already gone home without removing the lock. What must happen before anyone else removes it?

Answer: The employer must verify the employee is not at the facility, make a reasonable effort to contact them about the removal, and make sure they are informed before resuming work at that location

This is the specific exception procedure for removing a device applied by someone else. It has to be a documented procedure that gives equivalent protection to having that employee remove their own lock — not an informal judgment call.

Source: OSHA 29 CFR 1910.147(e)(3)

11. Several authorized employees are servicing the same machine at once. What must a group lockout procedure provide?

Answer: Protection equivalent to an individual lock — typically a lock box or hasp where each worker applies and removes their own personal lock

Group procedures must give each worker the same level of protection a personal lock would. A common method: one authorized employee has primary responsibility, and every crew member still applies their own lock to a group lock box, removing it only when they personally stop working.

Source: OSHA 29 CFR 1910.147(f)(3)

12. A locked-out job carries across a shift change. What does OSHA require to maintain continuity of protection?

Answer: A documented procedure for the orderly transfer of lockout/tagout protection between the off-going and on-going employees, so the equipment is never left unprotected

Shift and personnel changes are a known weak point — the equipment should never sit unlocked between crews. The standard requires a procedure for handing off protection, not an informal gap.

Source: OSHA 29 CFR 1910.147(f)(4)

13. Before removing lockout/tagout devices and re-energizing the machine, what must the authorized employee check first?

Answer: That nonessential items are removed, guards and other safety devices are reinstalled, and employees are safely positioned and notified before re-energizing

This is the "release from lockout/tagout" step: a visual check of the work area, confirming components are operationally intact, and notifying affected employees that the machine is about to be re-energized — before anyone removes a device.

Source: OSHA 29 CFR 1910.147(e)(1)–(2)

14. A machine needs to be briefly re-energized to test or reposition it during the job. What does OSHA require?

Answer: Remove nonessential items, re-energize only as needed for the test or positioning, then de-energize and reapply the lockout/tagout devices before work continues

Testing or positioning is the one scenario where temporary removal of the devices is built into the standard — but it is a defined sequence, not an informal shortcut, and the machine goes back under lockout afterward.

Source: OSHA 29 CFR 1910.147(f)(1)

15. An outside contractor’s crew will work on equipment normally covered by your plant’s lockout program. What does OSHA require?

Answer: The on-site employer and the outside employer must inform each other of their respective energy control procedures, and every employee must comply with the restrictions of whichever procedure applies

Both employers have to exchange procedures so nobody is working under rules they do not know about. This is the same information-sharing principle construction’s confined-space standard uses for multi-employer sites.

Source: OSHA 29 CFR 1910.147(f)(2)

16. Which of these is actually exempt from the full lockout/tagout procedure under 1910.147?

Answer: Unplugging cord-and-plug-connected equipment, as long as the plug stays under the exclusive control of the employee doing the work

The cord-and-plug exception only works because the plug itself — in that one employee’s physical control — is the energy-isolating device. Horsepower and job duration have nothing to do with whether lockout applies.

Source: OSHA 29 CFR 1910.147(a)(2)(ii)

17. Equipment installed or substantially modified after January 1, 1990, and capable of being locked out, must be designed so that it:

Answer: Can accept a lockout device

Newer equipment that is capable of accepting a lockout device must be used with lockout, not tagout alone, whenever the employer has that choice. Tagout-only programs are for equipment that genuinely cannot accept a lock.

Source: OSHA 29 CFR 1910.147(c)(2)(ii)

18. A tool change on a production line is "minor servicing" that may skip the full lockout procedure only when it is:

Answer: Routine, repetitive, and integral to the production process, and alternative measures provide effective protection

The minor-servicing exception is narrow and specific — routine, repetitive, part of normal production, and backed by alternative protective measures (like guards or a point-of-operation device). "It is quick" or "the worker is experienced" are not the test.

Source: OSHA 29 CFR 1910.147(a)(2)(iii)