Lockout tagout meaning: what LOTO actually requires at work

Last updated 2026-07-09

What does lockout tagout actually mean?

Lockout tagout, almost always shortened to LOTO, cuts off hazardous energy to a machine before anyone works on it. The name is two physical acts: putting a lock on an energy-isolating device so it can't be turned back on, and hanging a tag that warns everyone the equipment is disabled on purpose.

The "energy" part is broader than most people expect. OSHA's standard covers electrical, mechanical, hydraulic, pneumatic, chemical, and thermal energy. ^[1] A hydraulic press. A conveyor belt holding stored tension. A steam pipe. A capacitor bank that still carries a charge after the power's off. All of it is covered. The worry underneath is plain: machines move, release pressure, or shock people when a worker assumes the power is dead and it isn't.

"Hazardous energy control" is the formal term OSHA uses. LOTO is the usual method. The standard also allows tagout-only programs when equipment can't physically accept a lock, but those carry stricter conditions, because a tag is a lot easier to remove or ignore than a padlock.

Want the wider regulatory picture? Our overview of osha explains how the agency writes and enforces standards like this one.

Which OSHA standard governs lockout tagout?

The main standard is 29 CFR 1910.147, titled "The control of hazardous energy (lockout/tagout)." ^[1] It lives in Part 1910, OSHA's general industry rules. A few related standards matter too:

• 29 CFR 1910.333 covers electrical safe work practices and points back to lockout for electrical work. ^[9]
• 29 CFR 1926.417 is the construction version, and construction sites follow different rules in several spots.
• Process Safety Management facilities (29 CFR 1910.119) layer extra energy-control requirements on top of 1910.147.

The standard says its purpose is "to establish minimum performance requirements for the control of such hazardous energy." ^[1] That word "minimum" earns its place. States running their own OSHA-approved programs (called State Plans) can set stricter rules, and some do. Cal/OSHA in California, for one, has energy-control requirements worth checking if you operate there. ^[10]

If your state has no State Plan, federal 1910.147 is the rule. No substitute document. No equivalent guideline you can follow instead. The written program, the procedures, the training, the inspections all trace back to that single CFR section.

Why does lockout tagout matter, and what are the injury numbers?

OSHA estimates proper LOTO prevents about 120 deaths and 50,000 injuries a year among covered workers. ^[2] The agency also figures that failing to control hazardous energy causes roughly 10 percent of serious accidents in some industries.

Bureau of Labor Statistics data helps size the exposure. The "caught-in or between" category, which captures most machine and energy-control deaths, recorded hundreds of worker fatalities in 2022. ^[3] Not every one is a LOTO failure, but machine guarding and energy control account for a big share.

On enforcement, 1910.147 shows up in OSHA's top ten most-cited general industry standards year after year, usually somewhere in the fifth-through-seventh range. ^[4] In fiscal 2023, OSHA issued 2,554 LOTO citations with proposed penalties over $20 million. ^[4] Smaller infractions draw modest penalties, but a willful violation can hit $156,259 as of the 2024 penalty adjustments. ^[5]

The reason those numbers exist: getting this wrong is fast and catastrophic. A worker pulled into an auger, crushed by a press that cycles without warning, or shocked by equipment assumed dead has almost no chance to fix the mistake. That injury profile is why OSHA treats LOTO as a priority for inspectors.

For the full procedural walkthrough, see lockout tagout once the foundational meaning here makes sense.

What types of energy does lockout tagout cover?

29 CFR 1910.147 defines "energy source" as "any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other energy." ^[1] Here's what each type looks like on the floor:

Energy Type	Common Examples	Why It's Dangerous Even After Apparent Shutoff
Electrical	Motors, control panels, capacitors	Capacitors store charge; residual voltage can persist
Mechanical	Springs, flywheels, counterweights	Stored tension or kinetic energy causes unexpected movement
Hydraulic	Presses, lifts, injection molding	Pressurized fluid remains after the pump is off
Pneumatic	Air cylinders, nail guns, compressors	Air pressure stays in lines; cylinders can actuate
Chemical	Process piping, reactors	Pressure and reactive materials persist in systems
Thermal	Steam lines, ovens, heated rollers	Surfaces and fluids stay dangerously hot; steam lines hold pressure
Gravitational	Suspended loads, raised vehicle lifts	Gravity acts continuously; anything elevated can fall

Gravitational energy isn't spelled out in the energy-type list, but it's built into the standard's rules on blocking and restraining parts before work starts. A vehicle on a lift is the classic case. The lift itself might be locked out, but the vehicle has to be supported independently, because the lift could fail.

Residual energy is the concept that trips up most employers. Cutting power or closing a valve is step one, not the last step. The standard requires workers to release, restrain, or otherwise render safe any residual or stored energy before work begins. ^[1] That's why real LOTO procedures include bleeding hydraulic lines, discharging capacitors, and blocking suspended parts.

What are the key definitions in the LOTO standard?

The definitions section, 1910.147(b), sets the terms that decide who does what. These aren't word games. Getting a definition wrong opens a compliance gap that walks straight into a citation.

Authorized employee: The person who locks or tags out the machine and does the service or maintenance. Gets detailed training on the specific energy sources for the machines they touch.

Affected employee: Anyone whose job means operating a machine that's about to be locked out, or working in an area where lockout is in effect. They don't apply locks. They do have to know why the equipment is locked and that they can't restart it.

Other employees: Everyone else who works where LOTO procedures might be used. Basic awareness training so they understand what a lock and tag mean.

Energy-isolating device: A mechanical device that physically blocks the transmission of energy. Manually operated circuit breakers, disconnect switches, line valves, and blocks all qualify. ^[1] A push button or selector switch does not.

Lockout device: Usually a uniquely keyed padlock that holds an energy-isolating device in the safe position.

Tagout device: A warning tag with an attachment, fastened securely to an energy-isolating device, telling everyone the equipment can't be energized until the tag comes off.

The split between authorized and affected employees drives your whole training program. Authorized people need procedure-specific training. Affected people need to understand the hazard well enough to leave the equipment alone.

What must a lockout tagout written program include?

29 CFR 1910.147(c)(1) requires a written energy control program. ^[1] The standard spells out what it has to cover:

• The scope, purpose, and rules for using energy control procedures
• Specific procedures for shutting down, isolating, blocking, and securing machines
• Requirements for releasing stored or residual energy
• Steps for placing, removing, and transferring lockout or tagout devices
• Testing and positioning to verify isolation
• Requirements for outside contractors
• Periodic inspections of the procedures

A program that just says "employees must follow LOTO" fails. OSHA compliance officers look for machine-specific procedures, not a generic policy statement. Service ten different machines and you may need ten separate written procedures.

Each machine-specific procedure lists the shutdown steps, the location and type of every energy-isolating device, the type and magnitude of energy present, and the methods to control it. ^[1] For a shop with dozens of machines, building that library is the heaviest documentation lift in the whole program.

This is where a tool like SafetyFolio actually helps. The safety program generator walks you through the required written elements in about 15 minutes, so you start from a compliant framework instead of a blank page. You'll still have to add your machine-specific procedure details, which take on-site knowledge no software can supply.

What is the step-by-step lockout tagout procedure?

The standard never says "eight steps," but trainers and compliance officers commonly organize the required actions that way. Here's how the sequence maps to 1910.147(d) and (e):

1. Prepare for shutdown. Identify every energy source, its type and magnitude. Gather the right locks, tags, and blocking gear.

2. Notify affected employees. Tell the people who run or work near the equipment that it's going down and why.

3. Shut down the equipment. Use the normal stopping procedure.

4. Isolate the energy source. Operate every energy-isolating device so the machine is cut off from its energy source(s). ^[1]

5. Apply the lockout or tagout device. The authorized employee puts their own lock (or tag, if a lock isn't feasible) on each energy-isolating device. Every worker on the job applies their own lock.

6. Release or restrain stored energy. Bleed hydraulic lines, discharge capacitors, block suspended parts, release spring tension, vent pressurized systems. This is the step most often skipped.

7. Verify isolation. Before work starts, the authorized employee confirms the equipment is dead by trying to start it, testing with a meter, or both. ^[1]

8. Perform the work.

Restoring the equipment follows its own steps in 1910.147(e): remove all tools and materials, put guards back, clear all employees, remove lockout/tagout devices (only the person who installed a device removes it), notify affected employees, then restore energy.

One rule gets misunderstood constantly: only the person who applied a lock removes it. If that person leaves the site, the written program must include a documented procedure for removing the lock under tight conditions, usually requiring supervisor sign-off and verification that the worker is off-site and out of danger.

What training does LOTO require, and who needs it?

Training rules sit in 1910.147(c)(7). Training happens before an employee performs energy control duties, and retraining kicks in when there's reason to believe someone's deviating or when procedures or equipment change. ^[1]

Here's the training by employee type:

Authorized employees learn to recognize applicable hazardous energy sources, the type and magnitude of energy present, and the methods to isolate and control it. Hands-on, machine-specific knowledge.

Affected employees learn the purpose and use of the energy control procedure. They don't need the full technical depth. They do need to understand why the lock is there and what "do not operate" means.

Other employees who work where LOTO may be used just need to know that locked-out equipment stays off.

The standard requires training to be certified in writing, with each employee's name, the date, and the subject. ^[1] OSHA inspectors ask for these records. Undated or generic certificates don't count.

Retraining under 1910.147 isn't tied to a calendar. It's triggered when an inspection reveals a deficiency, when a new hazard shows up, or when there's reason to believe an employee doesn't understand or follow the procedures. Plenty of safety pros still run an annual refresher as practical risk management, even though the standard doesn't demand one on that schedule.

For the broader picture on OSHA training rules, see our article on osha training.

What is the annual LOTO inspection requirement?

29 CFR 1910.147(c)(6) requires each authorized employee's energy control procedure to be inspected at least once a year. ^[1] This is a procedural review, not a self-certification. An authorized employee who doesn't use the procedure runs the inspection, working with an authorized employee who does use it.

The annual inspection has to:

• Review the energy control procedure with each authorized employee who uses it
• Certify that the inspection happened (date, equipment, employee names, inspector name)
• Stay on record with the employer

For lockout procedures, the review can happen during normal maintenance. For tagout procedures, it also has to cover any tagout limitations that were identified.

This is separate from any OSHA audit. It's an internal check you run on your own program to catch drift before an inspector does. Companies that keep these records straight tend to fare far better in inspections, because the paper trail shows an active program instead of a binder gathering dust on a shelf. ^[8]

When does tagout-only apply instead of lockout?

Lockout is the preferred method. The default is simple: if a machine has an energy-isolating device that can take a lock, you lock it. Tagout-only is allowed only when the device "cannot be locked out." ^[1]

Run a tagout-only setup and you have to demonstrate it gives protection equal to lockout. That's a real burden. The standard lists extra measures required for tagout: removing an isolating circuit element, blocking a controlling switch, opening an extra disconnecting device, or removing a valve handle. ^[1]

Most modern equipment can be locked out. Tagout-only usually shows up with older machinery that predates hasp and lockout hardware, or odd configurations where the isolating device has no place for a lock. If you can retrofit a lockout point, the standard expects you to do it.

One thing worth keeping straight: a tag warns, it doesn't block. The standard says tagout devices have to clearly state "Do Not Start," "Do Not Open," "Do Not Close," "Do Not Energize," or "Do Not Operate." ^[1] A tag can be torn off, blown away, or ignored. A lock needs a key or a tool. That's why tagout-only is the fallback, never the first choice.

How does group lockout work when multiple workers are on the same equipment?

When two or more employees work on the same equipment, each one gets personal protection. ^[1] The standard requires every authorized employee to apply their own lockout or tagout device. The crew doesn't share a single lock.

In practice, this runs through a group lockout box (sometimes called a hasp and lockbox setup). Here's the mechanics:

A primary authorized employee puts a master lock on the energy-isolating device and on a group lockout box. Each worker then adds a personal lock to the box. The equipment can't be re-energized until the master lock comes off, and the master lock can't come off until every worker has pulled their personal lock from the box.

Shift changes complicate it. If a first-shift crew locks out equipment and a second shift will keep going, the program has to spell out the transfer. The outgoing crew's locks usually stay on until the incoming crew applies theirs. The written program describes the exact procedure for shift or personnel changes.

Contractors raise the same problem. 29 CFR 1910.147(f)(2) requires the host employer and the contractor to tell each other their LOTO procedures and to make sure employees understand and follow the procedures in effect at the worksite. ^[1] When a contractor uses different procedures, you need active coordination, more than two crews working past each other.

What are the most common LOTO violations OSHA cites?

Based on OSHA's inspection history and how the standard is built, the frequent deficiencies follow a predictable pattern. ^[8]

No written program. The most basic gap. Some employers know the concept but never documented a program.

Generic procedures instead of machine-specific ones. "Turn off the machine and put a lock on it" without naming specific energy sources, isolating devices, and steps for each machine fails 1910.147(c)(4).

Missing or incomplete training records. Training may have happened informally, but no certification exists. Or records cover some employees and not others.

Failure to address stored energy. Workers cut power but skip bleeding hydraulic systems or discharging capacitors. This is the gap most likely to hurt someone.

No annual inspection. The review happened once when the program was written, then never again.

Contractor coordination failures. A contractor works on host equipment with no documented coordination between the two programs.

Tagout used where lockout is feasible. Equipment that could take a lock uses only a tag, without the extra safeguards.

OSHA's data shows citations under 1910.147 tend to run in clusters. If one element is missing, usually several are. A facility that skipped annual inspections often has outdated procedures and thin training records too. That's why a compliance officer who finds one deficiency digs into the whole program.

For how the inspection and citation process works more broadly, see our article on incident report and what triggers an OSHA investigation.

Does lockout tagout apply to small businesses?

Yes. 29 CFR 1910.147 applies to any general industry employer whose workers service or maintain machines where unexpected energization or startup could happen. ^[1] No small-business exemption. No employee-count threshold.

The standard does carve out a few situations. Work on cord-and-plug equipment when the plug is within sight of the worker and under their exclusive control. Certain hot tap operations. Minor tool changes where the routine production operation creates no exposure to unexpected energization. ^[1] These carve-outs are narrower than most small employers hope.

A three-person shop with one mill and one lathe still needs a written LOTO program, machine-specific procedures for both machines, and training certifications for whoever services them. The paperwork scales down with fewer machines. The requirement doesn't disappear.

Here's the honest note for small operators. The real risk isn't the first-time citation penalty, often in the $1,000 to $15,000 range for serious violations. It's the incident. A small business losing a key employee to a severe injury, or facing a willful citation after someone gets hurt, is a business-ending event. The program is worth building.

SafetyFolio's safety program generator is built for small business owners who need a compliant written program without hiring a consultant. It won't do the machine-specific procedure work for you, but it gets the required framework documented fast.

Frequently asked questions

What is the simple definition of lockout tagout?

Lockout tagout means using a physical lock (and a warning tag) to de-energize a machine and keep it from starting while someone works on it. The lock goes on the energy-isolating device, like a circuit breaker or valve, so no one can accidentally restore power. OSHA's 29 CFR 1910.147 requires this for service and maintenance in general industry.

What is the difference between lockout and tagout?

Lockout uses a physical lock to hold an energy-isolating device in the safe position. Tagout uses only a warning tag on that device. A lock is physically restrained; a tag is only a warning and can be removed or ignored. Lockout is preferred. Tagout-only is allowed under 29 CFR 1910.147 only when equipment can't accept a lock, and it requires extra safeguards.

Who is required to follow LOTO procedures?

Any general industry employer whose workers service or maintain machinery where unexpected energization could cause injury must follow 29 CFR 1910.147. There's no exemption for small businesses or low headcount. Three categories of employees carry different training requirements: authorized employees who apply locks, affected employees who operate the equipment, and other employees who work nearby.

What does LOTO stand for?

LOTO stands for lockout/tagout. The abbreviation combines the two physical safety steps: putting a lock on an energy-isolating device (lockout) and hanging a warning tag on it (tagout). The terms travel together because most procedures involve both, though either can exist alone depending on the equipment and circumstances.

How often must LOTO procedures be inspected?

At least once a year, per 29 CFR 1910.147(c)(6). The inspection has to be done by an authorized employee other than the one using the procedure, must review the procedure with each authorized employee who uses it, and must produce a written certification noting the date, equipment, employees involved, and the inspector's name. The employer keeps the record.

Can an employer use a tagout-only program?

Only if the equipment can't be locked out. Under 29 CFR 1910.147, lockout is preferred because a physical lock gives more protection than a tag alone. If tagout-only is used, the employer has to add protective measures such as removing fuses, blocking controlling switches, or opening extra disconnecting devices to reach protection equal to lockout.

What types of energy does lockout tagout cover?

29 CFR 1910.147 explicitly covers electrical, mechanical, hydraulic, pneumatic, chemical, and thermal energy, plus any other energy source. Gravitational energy (suspended loads, elevated machine parts) is handled through the stored-energy requirements. The key concept is residual or stored energy: cutting the power supply isn't enough if energy stays in the system after isolation.

What happens if an OSHA inspector finds LOTO violations?

OSHA classifies 1910.147 violations as serious, repeat, or willful based on the employer's knowledge and history. Serious violations carry penalties up to $16,131 per violation as of 2024. Willful and repeat violations can reach $161,323 per violation. OSHA issued 2,554 LOTO citations in FY2023, with total proposed penalties over $20 million.

Do contractors need to follow LOTO procedures at a host employer's site?

Yes. 29 CFR 1910.147(f)(2) requires the host employer and outside contractors to tell each other their lockout/tagout procedures and to make sure all employees understand and follow the procedures in effect at the worksite. If the contractor's program differs from the host's, both parties have to coordinate so no gaps or conflicts exist while they share the work.

What is group lockout and when is it required?

Group lockout is required whenever more than one employee works on equipment under energy control. Each worker applies their own personal lock. A common method uses a group lockout box: one person puts a master lock on the energy-isolating device and on the box, then each worker adds a personal lock to the box. No energy returns until every personal lock is off.

Is lockout tagout required for cord-and-plug equipment?

Not in most cases. 29 CFR 1910.147 exempts cord-and-plug equipment when the plug is under the exclusive control of the worker doing the job and is unplugged and within sight. If someone else could reach and reinsert the plug, or if it's out of sight, the exemption doesn't apply and full energy control procedures are required.

How many injuries does LOTO prevent each year?

OSHA estimates that following lockout tagout prevents about 120 deaths and 50,000 injuries a year among the workers covered by 29 CFR 1910.147. These figures come from OSHA's regulatory analysis for the standard. OSHA also cites failure to control hazardous energy as roughly 10 percent of serious accidents in some covered industries.

What training records are required under the LOTO standard?

29 CFR 1910.147(c)(7)(iv) requires employers to certify that training happened. The certification must include each employee's name, the date, and the subject. Generic or undated certificates don't satisfy the requirement. Records have to be kept and available to OSHA on request. The standard sets no retention period, but keeping records three to five years is common practice.

What is an energy-isolating device?

Under 29 CFR 1910.147(b), an energy-isolating device is a mechanical device that physically prevents the transmission or release of energy. Examples include manually operated circuit breakers, disconnect switches, line valves, and blocking devices. Push buttons, selector switches, and other control-circuit devices are not energy-isolating devices under the standard, because they don't physically interrupt the energy path.

Sources

1. OSHA, 29 CFR 1910.147 - The Control of Hazardous Energy (Lockout/Tagout): Full text of the LOTO standard including definitions, written program requirements, training, inspection, and procedure requirements
2. OSHA, Control of Hazardous Energy (Lockout/Tagout) safety topic page: OSHA estimates LOTO compliance prevents approximately 120 deaths and 50,000 injuries annually
3. Bureau of Labor Statistics, Injuries, Illnesses, and Fatalities program: Caught-in or between fatality data from BLS occupational injury and fatality statistics
4. OSHA, Top 10 Most Frequently Cited Standards (FY2023): 29 CFR 1910.147 cited 2,554 times in FY2023 with more than $20 million in proposed penalties
5. OSHA, OSHA Penalties page: Maximum willful and repeat violation penalties as of 2024 OSHA penalty adjustments
6. OSHA, Standard Interpretations for 1910.147: OSHA letters of interpretation clarifying definitions and application of 1910.147
7. OSHA, Compliance Directive CPL 02-00-147 - Inspection Procedures for 1910.147: OSHA enforcement guidance on how compliance officers inspect LOTO programs including program elements and common deficiencies
8. OSHA, 29 CFR 1910.333 - Selection and Use of Work Practices (electrical): Related standard referencing lockout requirements for electrical work in general industry
9. OSHA, State Plans page: Information on State Plan programs that may set stricter energy control requirements than federal OSHA