LOTO Explained: Lockout/Tagout Steps for Safer Maintenance

LOTO, short for lockout/tagout, is an energy-control process that prevents a machine from starting or releasing hazardous energy while workers service or maintain it. For facility maintenance and industrial operations teams, a reliable LOTO program turns a planned shutdown into a controlled sequence that protects authorized employees, affected employees, equipment, and production continuity.

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This guide explains the core steps in OSHA's general-industry control of hazardous energy standard, 29 CFR 1910.147. It is educational guidance, not a substitute for a workplace-specific written procedure, employee training, or a competent safety review. Every employer must adapt the process to the machine, energy sources, work scope, and people involved.

What is LOTO, and what does it control?

LOTO is a documented method for isolating hazardous energy and preventing its unexpected release during servicing or maintenance. It uses shutdown, isolation, lockout or tagout, stored-energy control, verification, and controlled restoration so equipment remains inoperative until authorized work is complete.

Hazardous energy is not limited to electricity. Depending on the equipment, it may include hydraulic pressure, pneumatic pressure, steam, gas, water pressure, mechanical motion, gravity, heat, chemical energy, radiation, or energy stored in springs, flywheels, capacitors, or elevated components. A machine can appear switched off and still contain enough stored or residual energy to injure someone.

OSHA 29 CFR 1910.147 generally applies when unexpected energization, startup, or release of stored energy could cause injury during servicing or maintenance. The standard also describes circumstances where normal production work becomes covered, such as when a worker must remove a guard, bypass a safety device, or place a body part in a danger zone. Other industries and operations may have different applicable requirements, so employers should confirm the correct standard for their work.

Who is involved in a LOTO procedure?

A safe LOTO procedure assigns clear responsibilities before anyone approaches the hazard. The most important distinction is between authorized employees who apply energy controls and affected employees who operate the equipment or work in the area. Other employees may also need awareness training if they could encounter locked-out equipment.

An affected employee may become an authorized employee when their assigned duties include servicing or maintenance covered by the energy-control procedure. Job titles alone do not determine the role. The employer should base the designation on the work the person is trained and authorized to perform.

How should a team plan LOTO before shutdown?

LOTO planning starts with a machine-specific energy survey, not with picking up a padlock. Before shutdown, the team should identify every energy source, every isolation point, stored-energy hazards, required devices, affected workers, the work boundary, and the method for proving zero energy.

Build or review the written procedure

The procedure should name the machine or system, explain the shutdown sequence, show or identify each energy-isolating device, describe how stored energy is released or restrained, and state how workers will verify isolation. A generic poster can reinforce the sequence, but it should not replace a procedure that reflects the actual equipment.

Walk the energy path

Trace energy from its source to the point where a worker could be exposed. Check electrical disconnects, breakers, valves, pneumatic lines, hydraulic accumulators, steam or gas supplies, elevated parts, rotating components, and connected equipment. Look for secondary feeds, backflow, gravity, heat, pressure, and automatic controls that could restore energy.

Choose equipment that matches the isolation point

Use a device that fits the isolating mechanism and remains secure for the full duration of the work. Depending on the application, that may include circuit-breaker lockouts, plug lockouts, valve lockouts, pneumatic lockouts, lockout hasps, tags, padlocks, or a group lockbox. Product choice should follow the written procedure and a hazard assessment, not the other way around.

Coordinate people and timing

Notify affected employees before the shutdown and explain how long the equipment may be unavailable. If several crews, shifts, contractors, or departments are involved, establish who controls the procedure, how each person applies personal protection, and how the handoff will occur. The person in charge should be identifiable throughout the job.

What are the seven LOTO steps?

The seven LOTO steps are notify, shut down, isolate, apply lockout or tagout, control stored energy, verify isolation, and complete the work through an orderly restoration. The sequence must be followed in the order required by the machine-specific procedure, with no step skipped because a shutdown appears routine.

1. Notify affected employees. Tell operators, nearby workers, supervisors, and other people who may be affected that the machine will be shut down for servicing. Explain which equipment is involved, what work is planned, and when normal operation is expected to resume. Notification prevents someone from trying to restart equipment or entering the work area without understanding the hazard.
2. Shut down the equipment. Use the normal stopping control, following the manufacturer's instructions and the employer's procedure. Do not rely on an emergency stop alone if it does not isolate energy. Make sure moving parts have stopped and that the shutdown does not create a new hazard for people nearby.
3. Isolate every energy source. Operate each energy-isolating device identified in the procedure. This may involve opening a disconnect, closing a valve, blocking a mechanical component, or separating a connection. Push buttons, selector switches, software controls, and interlocks are control devices, not energy-isolating devices. They may help stop equipment, but they do not replace physical isolation.
4. Apply locks and tags. Place an individually identified lock and tag on each required energy-isolating device, or use the approved group-lockout method. The tag should clearly communicate that the equipment must not be operated and identify the person or group responsible. A tag is a warning device, not a physical restraint, so tagout-only methods require the level of protection required by the applicable standard and procedure.
5. Release or restrain stored energy. Bleed, drain, vent, discharge, block, ground, lower, or otherwise secure residual energy as the procedure requires. Relieve pressure in pneumatic and hydraulic lines, discharge capacitors, block elevated parts, restrain springs, and allow hot surfaces to cool when those hazards are present. Continue checking because stored energy can reaccumulate after it appears to be gone.
6. Verify zero energy. Confirm that the equipment is isolated before work begins. First check that people are clear, then test the normal controls to confirm that the machine will not start. Use appropriate test equipment to verify the absence of electrical energy where required, and return controls to the off or neutral position after testing. A visual inspection alone is not enough when a reliable test is available. The authorized employee should document or otherwise confirm the verification required by the procedure.
7. Perform the work and restore safely. Complete the servicing only after isolation is verified. When work is complete, inspect the area, reinstall guards, remove tools and temporary blocks as directed, and confirm that everyone is clear. Each authorized employee removes their own lock or follows the documented exceptional-removal process. Notify affected employees before re-energization, remove locks and tags according to the procedure, and return the equipment to service in a controlled manner.

For a detailed reference to the general-industry requirements, review OSHA 29 CFR 1910.147, The Control of Hazardous Energy. The regulation includes requirements for preparation, shutdown, isolation, lockout or tagout application, release of stored energy, verification, removal, and restoration.

When does LOTO require special coordination?

Some jobs require more than one worker or one shift to maintain control of hazardous energy. The written procedure should explain how the team preserves personal protection when responsibility changes, rather than relying on informal promises or a single shared lock.

Group lockout

In a group lockout, every authorized employee needs a personal lock or an equivalent method of personal protection. A group lockbox can help when multiple isolation points are secured by a designated coordinator, but each worker should control their own lock on the box or approved group mechanism. Removing one person's lock must never remove protection for another worker who is still exposed.

Shift or personnel changes

Shift changes must be planned so the outgoing employee's protection overlaps with the incoming employee's protection. The handoff should verify that the equipment remains isolated, identify the work status, and transfer control before an outgoing lock is removed. The procedure should describe the exact sequence and the person responsible for confirming continuity.

Outside contractors

When an outside employer performs servicing, the host employer and contractor should inform each other of their respective energy-control procedures. Both groups need to understand the isolation boundary, who is authorized to operate or service the equipment, and how the two procedures coordinate. A contractor's presence does not eliminate the host employer's responsibility to control site hazards.

Testing or repositioning during service

Some work requires a temporary re-energization to test or reposition a machine. The procedure should define how workers clear tools and people, remove controls temporarily, energize only for the limited test, shut down again, reapply isolation, and verify zero energy before work resumes. Unplanned testing is a common point of failure because the team may treat a temporary exception as a normal restart.

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What training and inspections does OSHA require?

An energy-control program depends on training that matches each employee's role and duties. Authorized employees need practical instruction on recognizing hazardous energy, the type and magnitude of energy in their work, the methods and means of isolation, and how to apply, use, and remove the procedure. Affected employees need to understand the purpose and use of the procedure and the prohibition against restarting or bypassing locked-out equipment. Other employees need awareness of the procedure and the prohibition against interfering with it.

Training should be refreshed when a job assignment, machine, process, energy-control procedure, or employer practice changes in a way that creates a new hazard or changes the employee's responsibilities. Retraining is also appropriate when an inspection identifies a deviation or when an employee's knowledge or use of the procedure is inadequate. The employer should certify completion with the employee's name and training date, along with the information required by the company's program.

OSHA 29 CFR 1910.147 requires a periodic inspection of each energy-control procedure at least annually to confirm that the procedure and standard requirements are being followed. The inspection must be performed by an authorized employee other than the one using the procedure being inspected. The review should cover the responsibilities of the authorized employees and, when tagout is used, the applicable responsibilities of affected and authorized employees. The employer must certify that the inspection occurred, including the machine or equipment, inspection date, employees included, and inspector.

What should a written LOTO procedure include?

A useful written procedure is specific enough that a trained authorized employee can follow it without guessing. OSHA does not make a generic checklist a substitute for the employer's energy-control program. Use the following list as a review prompt, then tailor it to the equipment and site.

• Machine or system name, location, and identification number.
• Normal operating controls and the approved shutdown method.
• Every primary and secondary energy source, including the type and magnitude.
• Each energy-isolating device and its exact location.
• Required locks, tags, hasps, blocking devices, test equipment, and personal protective equipment.
• Methods for bleeding, draining, venting, discharging, blocking, grounding, lowering, or restraining stored energy.
• Known hazards that may remain after isolation, including heat, gravity, pressure, chemicals, or connected systems.
• How an authorized employee verifies isolation and zero energy.
• Rules for group work, shift changes, contractor coordination, and temporary testing.
• Inspection, training, documentation, and corrective-action requirements.
• Controlled steps for removing locks and tags, notifying affected employees, and restoring service.

Keep procedures accessible at the point of use and update them after equipment modifications, process changes, incidents, near misses, or inspection findings. A procedure that no longer matches the machine can create false confidence even when the team follows every printed step.

What are common LOTO mistakes?

Most LOTO failures are not caused by a lack of a padlock. They happen when the team assumes that a control switch is an isolation point, overlooks a secondary energy source, or treats communication and verification as optional. Watch for these recurring problems:

• Locking only the obvious source: A machine may have multiple electrical feeds, pneumatic lines, hydraulic accumulators, gravity hazards, or connected equipment.
• Using a start button as proof of isolation: A failed control circuit or stored energy can make a machine appear safe when it is not. Follow the full verification method.
• Ignoring residual energy: Pressure, heat, elevated parts, rotating mass, and charged components can remain hazardous after shutdown.
• Using an unapproved shared lock: Personal protection must remain under the control of the authorized worker who is exposed.
• Failing to notify operators: People may attempt a restart when they do not know why equipment is unavailable.
• Removing another person's lock casually: Exceptional removal requires a documented process, confirmation that the employee is absent and clear, and notification before return to work.
• Leaving procedures unchanged after modifications: New controls, drives, valves, production cells, and connected equipment can change the energy path.
• Skipping annual inspection or retraining: A program is only reliable when the employer checks how it works in the field and corrects deviations.

How can a facility maintain a stronger LOTO program?

Start with the highest-risk machines and compare the written procedure with the equipment in front of you. Ask an authorized employee to walk through notification, shutdown, isolation, stored-energy control, verification, work, and restoration. Then correct gaps in the procedure, equipment, training, or supervision. The goal is not a checklist that looks complete. The goal is a repeatable energy-control process that workers can execute safely under real maintenance conditions.

Use the Safety Company lockout/tagout category to review devices for electrical, valve, pneumatic, plug, and related isolation applications. Choose equipment only after confirming that it matches the energy-control procedure and the isolating device.

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LOTO frequently asked questions

Is LOTO required for every maintenance task?

LOTO is generally required when servicing or maintenance could expose an employee to unexpected energization, startup, or release of stored energy. The exact scope depends on the equipment, work activity, and applicable standard. A responsible employer should evaluate the task and follow the workplace's written energy-control procedure instead of deciding based only on whether the job seems quick.

What is the difference between an authorized and affected employee?

An authorized employee performs servicing or maintenance and applies the energy-control procedure. An affected employee operates or uses the equipment, or works in the area where the service occurs, but does not apply the controls for that task. Both roles need training, but the authorized employee needs the deeper practical knowledge required to isolate and verify hazardous energy.

Can a tag replace a lock?

A tag is a warning device and does not provide the same physical restraint as a lock. When a lockable energy-isolating device is available, the employer's procedure generally uses lockout unless an allowed alternative provides full employee protection under the applicable standard. Tagout-only situations require careful evaluation, additional protective measures where required, and trained employees who understand the limitation.

How often should a LOTO procedure be inspected?

For general industry procedures covered by OSHA 29 CFR 1910.147, the employer must conduct a periodic inspection at least annually. The inspection should be performed by an authorized employee other than the employee using the procedure being inspected. The employer must certify the inspection and document the machine, date, employees included, and inspector.

What if a machine has more than one energy source?

Identify and isolate every energy source before work begins, including secondary feeds and stored or residual energy. The written procedure should name each isolation point and explain how to verify that each source is controlled. If a source cannot be isolated using the planned method, stop and obtain a competent safety review before proceeding.

Does this article replace LOTO training?

No. This article is general educational guidance and cannot account for a specific machine, energy-control procedure, employee assignment, or site condition. Employers must provide role-appropriate training, maintain written procedures, perform required inspections, and review the program with qualified safety personnel.

Equip your maintenance team with lockout/tagout kits

Safer maintenance starts with knowing the energy path, assigning responsibility, and verifying isolation every time. For equipment that fits your established procedure, browse Safety Company's lockout/tagout supplies or review the lockout/tagout kit selection for organized maintenance work.