June 22, 2026 Updated June 22, 2026 Steven Eaton

Lockout vs Tagout: What's the Difference? OSHA 1910.147 — Complete Guide for Maintenance and Safety Managers | WC Safety

What is the difference between lockout and tagout?

Short answer: Lockout vs tagout comes down to physical restraint: lockout places a lock on an energy-isolating device so it cannot be operated until the lock is removed, while tagout places only a warning tag with no physical hold. OSHA 29 CFR 1910.147 considers lockout the more reliable method and requires it whenever a device can be locked out, unless the employer can demonstrate that tagout provides full employee protection equivalent to lockout. Tagout always demands an additional means of protection.

Lockout vs tagout: what's the difference? OSHA 1910.147 explained (2026 Guide)

Under OSHA 29 CFR 1910.147, The Control of Hazardous Energy, every lockout/tagout program rests on one distinction: a lockout device is a physical restraint, and a tagout device is only a warning. Lockout means a lockout padlock or comparable device is affixed to an energy-isolating device — a breaker, valve, or disconnect — so it physically cannot be moved until the lock is removed. Tagout means a durable warning tag is attached in the same place, telling workers not to operate the device, but nothing physically prevents operation. OSHA treats lockout as the method that provides full employee protection, and tagout as the exception.

That difference drives the entire rule. When an energy-isolating device is capable of being locked out, 1910.147 requires the employer to use lockout unless they can demonstrate that tagout provides protection equivalent to lockout. This guide explains the lockout vs tagout difference precisely, decodes both device families, covers the rule on when each is allowed, and walks the standard six-step procedure step by step.

Why this matters.
The lockout vs tagout choice is not a labeling preference — it decides whether a worker is physically protected from an unexpected startup or only warned about one. A tag can be ignored, removed, or never seen, which is why OSHA, in 29 CFR 1910.147, requires lockout whenever a device is capable of accepting a lock and permits tagout alone only with an additional means of protection. The control of hazardous energy is consistently among OSHA's most-cited standards, and incidents tied to it — crushing, electrocution, amputation — are frequently fatal.

Part 1 — Lockout vs tagout: the core difference

Lockout and tagout are the two methods OSHA recognizes for isolating hazardous energy during servicing and maintenance. They share the same goal — keeping equipment from starting up or releasing stored energy while someone is exposed — but they protect in fundamentally different ways. The distinction between a physical restraint and a warning is the single most important concept in 1910.147.

What lockout is

Lockout is the placement of a lockout device on an energy-isolating device, holding it in a safe (de-energized) position. The device is typically a keyed safety padlock applied directly or through a hasp. Because the lock physically blocks operation and only the employee who applied it holds the key, lockout is a positive, physical restraint — OSHA's standard for full employee protection.

What tagout is

Tagout is the placement of a tagout device — a prominent, durable warning tag — on the energy-isolating device. The tag warns that the equipment must not be operated, but it provides no physical restraint. Anyone could still move the switch or valve. Tagout communicates a hazard; it does not prevent re-energization on its own.

Why the difference matters

A lock cannot be defeated by inattention; a tag can. That is why OSHA ranks lockout above tagout and treats tagout-only as a method that must be supplemented. The rest of 1910.147 — when each is allowed, what extra steps tagout demands — flows from this physical-restraint-versus-warning distinction.

Part 2 — Which one does OSHA require?

OSHA does not leave the lockout vs tagout choice to preference. 1910.147 establishes a clear hierarchy keyed to whether the energy-isolating device can accept a lock.

The capable-of-being-locked-out rule

When an energy-isolating device is capable of being locked out, the employer must use lockout — unless they can demonstrate that a tagout program will provide full employee protection equivalent to lockout. The burden is on the employer to prove that equivalence, which is difficult, so lockout is the default for any lockable device.

When tagout alone is permitted

When a device is not capable of being locked out, tagout may be used, but the employer must comply fully with all tagout provisions of the standard and train employees on the limitations of tags. Tagout is the fallback for older or non-lockable equipment, not a general substitute for lockout.

The 1990 retrofit requirement

To shrink the population of non-lockable equipment, 1910.147 requires that after January 2, 1990, whenever major replacement, repair, renovation, or modification of equipment occurs, or new machines are installed, energy-isolating devices must be designed to accept a lockout device. Over time, that pushes nearly all equipment toward lockout capability.

Attribute	Lockout	Tagout
Device	Lock (padlock) on an energy-isolating device, often via a hasp	Warning tag attached to the energy-isolating device
Protection type	Physical restraint — operation is blocked	Warning only — no physical restraint
OSHA reliability	Preferred; provides full employee protection	Lesser; a tag can be ignored or removed
When allowed	Required whenever a device is capable of being locked out	Only when a device cannot be locked out, or if proven equivalent to lockout
Extra measures required	None beyond proper application and verification	An additional means of isolation plus training on tag limits
Who removes it	Only the authorized employee who applied the lock	Only the authorized employee who applied the tag

Source: OSHA 29 CFR 1910.147, The Control of Hazardous Energy. Lockout is OSHA's method for full employee protection.

Part 3 — The extra protection tagout-only requires

Because a tag offers no physical hold, OSHA does not accept a tag by itself as equivalent to a lock. A compliant tagout-only program must add a second means to bring it up to the level of protection a lock provides.

Additional means of isolation

Acceptable additional measures include removing an isolating circuit element, blocking a controlling switch, opening an extra disconnecting device, or removing a valve handle to reduce the likelihood of inadvertent energization. The point is to make accidental operation physically harder, compensating for the missing lock.

Training on tag limitations

Employees in a tagout system must be trained that tags are warning devices only, must not be removed without authorization, must never be bypassed or ignored, and must be legible and understandable to everyone in the area. This training is a specific 1910.147 requirement, not an optional add-on.

Part 4 — The devices behind each method

The hardware makes the lockout vs tagout difference concrete. Lockout relies on physical devices that hold an isolation point; tagout relies on tags; most real programs combine both ("lock and tag").

Lockout hardware

Core lockout devices include keyed safety padlocks such as the Master Lock 410GRN lockout padlock or the American Lock A1107R safety padlock, lockout hasps that let several workers lock one isolation point at once, cable lockouts like the Qwork QS8899 steel cable locks for awkward or multiple points, plug lockouts for cord-and-plug equipment, and valve and breaker lockouts. A group lockout box lets a crew control a shared isolation under one key set.

Tags and stations

Tagout devices are standardized warning tags rated for the environment and attached so they cannot be removed accidentally. A lockout station or shadow board keeps the locks, hasps, and tags organized and visible at the point of use, which supports both compliance and quick application.

Part 5 — One lock per person

A foundational rule ties the hardware to the people: each authorized employee who works on the equipment applies their own lock and their own tag to the isolation point, and only that person removes their lock. If three people service one machine, three locks go on — usually through a hasp — and the equipment cannot be re-energized until the last person removes the last lock. This is why keyed-different lock sets such as the TRADESAFE TS1KD10R 10-pack of keyed-different locks and the ABUS 74/40 keyed-different padlock set exist, and why a lock is never removed by a substitute except under a strict, documented exception procedure. A compact personal kit like the Brady 123143 personal lockout/tagout kit gives each worker a self-contained set of devices.

Part 6 — Common lockout vs tagout mistakes

Most citations come from a few recurring errors: using tagout on equipment that is capable of being locked out, treating a tag as equivalent to a lock without the required additional means, failing to verify a zero-energy state before work begins, sharing or substituting locks between employees, and omitting the release of stored energy (springs, hydraulic pressure, capacitors, gravity). Each of these collapses the difference between warning and restraint that the standard is built to preserve.

Part 7 — Worked example: the six-step LOTO procedure on a conveyor

Here is how the lockout vs tagout difference plays out as the standard six-step procedure for taking a jammed conveyor out of service for maintenance, using devices stocked on this site:

Prepare for shutdown. Identify every energy source feeding the conveyor — electrical, plus any stored mechanical or gravitational energy — and confirm the correct isolation points. Stage your locks and tags from a wall-mounted lockout station so the right devices are on hand at the point of use.
Notify affected employees. Tell everyone who operates or works near the conveyor that it is being shut down for servicing and will be locked out, so no one attempts to start it.
Shut down the equipment. Stop the conveyor using its normal stopping procedure — controlled shutdown reduces the risk that comes from an abrupt stop.
Isolate the energy sources. Operate each energy-isolating device (the disconnect, breaker, or valve) to physically cut the equipment off from its energy. This is the step that lockout makes permanent until work is done.
Apply lockout (and tagout) devices. Each authorized employee applies their own padlock — for example a Brady SafeKey aluminum padlock — to the isolation point, using a hasp so multiple workers can lock one point, and attaches a warning tag. The lock is the physical restraint; the tag is the warning. For cord-and-plug equipment, a plug lockout secures the plug instead.
Verify zero energy (release stored energy and try out). Release or restrain any stored energy, then try the normal start controls to confirm the equipment will not operate — and return controls to off. Only after this verified zero-energy state does servicing begin.

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Reverse the sequence to restore power: clear tools and people, then have each employee remove only their own lock and tag. Build the program from keyed-different padlocks and hasps such as the TRADESAFE TSKAU10YL yellow lock set, and pair it with our reference on what lockout/tagout (LOTO) is to train the crew.

Frequently asked questions

What is the main difference between lockout and tagout?

Lockout uses a physical lock on an energy-isolating device so it cannot be operated, while tagout uses only a warning tag with no physical restraint. Under OSHA 29 CFR 1910.147, lockout provides full employee protection and is preferred; tagout merely warns. Most programs combine both, applying a lock and a tag together — for example a Brady SafeKey aluminum padlock with a durable warning tag.

Does OSHA require lockout or tagout?

OSHA requires lockout whenever an energy-isolating device is capable of being locked out, unless the employer can demonstrate that tagout provides protection equivalent to lockout. Tagout alone is permitted only when a device cannot accept a lock. Because proving equivalence is hard, lockout is the practical default for any lockable device under 1910.147.

Is tagout ever allowed by itself?

Yes, but narrowly. Tagout alone is allowed when an energy-isolating device is not capable of being locked out, and even then the employer must add an additional means of isolation and comply with all tagout provisions. A tag by itself, with no supplemental protection, is not accepted as equivalent to a lock.

Why is lockout considered more reliable than tagout?

A lock is a physical restraint that cannot be defeated by inattention — only by removing the lock with its key. A tag is a warning that can be ignored, removed, or unseen. OSHA 1910.147 explicitly treats lockout as the method providing full employee protection, which is why it ranks above tagout.

What extra steps does a tagout-only program require?

A tagout-only program must add a means to provide protection equivalent to lockout — for example removing an isolating circuit element, blocking a controlling switch, opening an extra disconnect, or removing a valve handle. It also requires specific training that tags are warnings only and must never be bypassed.

What is an energy-isolating device?

It is a mechanical device that physically prevents the transmission or release of energy — such as a manually operated electrical disconnect, a circuit breaker, a line valve, or a blank. Push buttons, selector switches, and other control-circuit devices are not energy-isolating devices. Lockout and tagout are applied to the energy-isolating device, not the control.

Can a lock and a tag be used together?

Yes, and they usually are. The common practice is "lock and tag": the lock supplies the physical restraint and the tag supplies the warning and identifies who applied it and why. You can build a combined program by pairing keyed-different safety padlocks with durable warning tags rated for the work environment.

Who is allowed to remove a lockout or tagout device?

Only the authorized employee who applied the device may remove it. If that person is unavailable, the device may be removed only under a specific, documented exception procedure that includes verifying the employee is not at the facility and making a reasonable effort to inform them. Substituting or sharing locks is prohibited.

What are the six steps of lockout/tagout?

Prepare for shutdown, notify affected employees, shut down the equipment, isolate the energy sources, apply lockout/tagout devices, and verify a zero-energy state by releasing stored energy and trying the start controls. Restoring power reverses the sequence. The worked example above walks each step on a conveyor, and the procedure mirrors OSHA 1910.147 Appendix A.

What is a group lockout and when is it used?

Group lockout is used when a crew services equipment together. Each authorized employee applies their own lock — often through a multi-hole hasp or a group lockout box — so the machine cannot be re-energized until the last worker removes the last lock. A keyed-different lock set gives each crew member a unique key, preserving the one-lock-per-person rule for shared work.

Why does each worker need their own lock?

So that no individual's protection depends on someone else. With one lock per person, the equipment stays isolated as long as any worker still has a lock on it, and each person controls their own exposure. This is why keyed-different lock sets and multi-lock hasps are standard in a compliant program.

Does 1910.147 require equipment to accept a lock?

For newer equipment, yes. After January 2, 1990, whenever major replacement, repair, renovation, or modification occurs, or new machines are installed, energy-isolating devices must be designed to accept a lockout device. This requirement steadily reduces the pool of equipment for which tagout-only is even permitted.

What does verifying a zero-energy state mean?

After isolating and locking the energy sources, you must release or restrain any stored energy — springs, hydraulic or pneumatic pressure, capacitors, gravity — and then try the normal start controls to confirm the equipment will not operate, returning controls to off. Only then is it safe to begin servicing. Skipping verification is a frequent and serious violation.

What is the difference between affected and authorized employees?

An authorized employee performs the lockout/tagout and the servicing, applying and removing the devices. An affected employee operates the equipment or works in the area and must be notified when it is locked out, but does not apply locks. The distinction determines who may place a lock and who simply needs to be informed.

Does lockout/tagout apply to electrical work only?

No. 1910.147 covers all hazardous energy — electrical, mechanical, hydraulic, pneumatic, chemical, thermal, and gravitational. A separate standard, OSHA 1910.333, adds lockout requirements for working on electrical circuits specifically, but energy control under 1910.147 spans every energy type a machine can store or transmit.

What products do I need to start a lockout/tagout program?

At minimum, keyed-different padlocks such as the Brady SafeKey aluminum padlock, a long-shackle lock like the ABUS 2ALHB for hasps, warning tags, and device-specific lockouts for the equipment you isolate. A lockout station keeps it all organized at the point of use, and a cable lock set such as the TRADESAFE steel cable lockout set covers valves and multi-point isolations.