Quick answer
Lockout/tagout (LOTO) is a safety procedure that shuts off machines or circuits, isolates their energy sources, and secures them with locks or warning tags so they cannot be turned on while someone works on them.
In U.S. workplaces, machine servicing is covered by OSHA 29 CFR 1910.147, the control of hazardous energy standard. Work on electrical utilization installations falls under Subpart S instead, where 1910.333(b) sets the lockout and tagging rule 1 2.
Quick facts
The key facts about Lockout/Tagout, with sources:
- Main OSHA standard
- 29 CFR 1910.147, control of hazardous energy 1
- Electrical work practices
- 29 CFR 1910.333(b)(2) lockout and tagging 2
- Construction
- 29 CFR 1926.417 lockout and tagging of circuits 3
- Lock or tag?
- Lockout where the device can be locked; tagout only if not, or with equal protection 1
- Procedure review
- Periodic inspection at least annually 1
- Tag attachment strength
- Must withstand at least 50 pounds of pull 1
Key takeaways
- LOTO keeps equipment from starting or re-energizing while people service it 1.
- OSHA requires a written program, training and periodic inspections at least annually 1.
- Use a lock wherever the isolating device can take one; tags alone are a fallback 1.
- Verify zero energy before work; a switch in the off position is not proof 1.
- Only the person who applied a lock removes it, with narrow exceptions 1.
What lockout/tagout means
Lockout means placing a lock on an energy isolating device, like a disconnect switch or a breaker, so it cannot be turned on. Tagout means attaching a warning tag that says the device must not be operated.
OSHA calls this the control of hazardous energy. It covers electricity and also mechanical, hydraulic, pneumatic, chemical and thermal energy. OSHA notes failures can cause electrocution, burns, crushing, cuts, amputations and fractures 4.
The rule applies when unexpected start-up or release of stored energy could injure workers during servicing or maintenance 1.
How LOTO protects a worker
A lock gives one person control of the energy. If five people work on a machine, each adds their own lock, often on a hasp. Power cannot come back until every lock is off. OSHA 1910.147(f)(3) covers this kind of group lockout 1.
Tags work differently. OSHA says tags are warnings, not physical restraints. That is why a tag must be legible, durable and firmly attached, with an attachment that holds at least 50 pounds 1. A tag relies on people reading and obeying it.
Stored energy is the hidden risk. Capacitors, springs, raised parts and pressure lines can still release energy after the switch is off. Step 5 below exists for that reason.
- Prepareknow the energy type, size and hazards; 1910.147(d)(1)
- Shut downorderly shutdown by established procedure; (d)(2)
- Isolateoperate every energy isolating device; (d)(3)
- Apply locks or tagsby authorized employees; (d)(4)
- Release stored energyrelieve, restrain, keep checking; (d)(5)
- Verifyconfirm isolation before work starts; (d)(6)
Source: [1]
Lockout vs tagout vs group lockout
| Method | What it is | When OSHA allows it |
|---|---|---|
| Lockout | Lock holds the isolating device off | Required where the device can be locked out 1 |
| Tagout | Warning tag on the device | Only where lockout is not possible, or the employer shows full equal protection 1 |
| Group lockout | Each worker adds a personal lock or tag under one responsible person | Permitted with equivalent protection 1 |
| Electrical LOTO | Lock and tag circuits feeding fixed equipment | 1910.333(b)(2) for deenergized parts 2 |
| Construction tagging | Tags on controls and at all points circuits can be energized | 1926.417 3 |
Example: what a written LOTO procedure contains
OSHA 1910.147(c)(4)(ii) lists what each documented procedure must spell out. The table maps that list to a simple electrical job, replacing a motor on a conveyor (illustrative only).
| OSHA requires | Example entry |
|---|---|
| Statement of intended use | Motor replacement on Conveyor 3 |
| Steps to shut down, isolate, block and secure | Stop at the control panel; open the motor disconnect; lock it |
| Steps for placing, removing and transferring locks and tags, and who is responsible | Each mechanic and electrician adds a personal lock to the group hasp |
| Steps to test and verify the energy control works | Try the start button; test for absence of voltage at the motor leads with a rated tester |
- Affected employees notified (1910.147(c)(9))
- Every energy source identified, including stored and mechanical
- Each isolating device locked, one lock per worker
- Stored energy relieved or restrained
- Start attempted and voltage tested: zero energy confirmed
Source: [1]
OSHA allows a limited exception from written procedures for simple equipment with a single energy source that meets every listed condition 1. Most electrical equipment in a facility does not qualify.
Where LOTO applies
- Factories, warehouses and plants with machines and conveyors.
- Commercial buildings during electrical service on fixed equipment 2.
- Construction sites, where controls and circuits are tagged under 1926.417 3.
- Maintenance on HVAC, elevators, pumps and compressors.
- Not covered by 1910.147: construction, agriculture, maritime work and exposure to electrical hazards in electric-utilization installations. Construction has 1926.417, and electrical installations fall under Subpart S (1910.333(b)) 1 2 3.
Why LOTO works
LOTO turns a habit, "I turned it off," into a system. Each step leaves physical proof: a lock on the switch, a tag with a name, a verified zero-energy test. Anyone walking up can see that work is under way.
It also puts control in the hands of the person at risk. Only the worker who applied a lock may remove it, except under a documented employer procedure 1.
Where LOTO can fail
Tags are only as good as people's attention. OSHA states that tags are essentially warning devices and do not physically restrain the equipment the way a lock does 1. They work only if people see and obey them.
Missed energy sources are a common gap. A machine may have a second feed, a backup battery or a control circuit from another panel. So the procedure starts with a full list of sources.
Skipping verification is another. A breaker may be mislabeled or welded shut inside. Testing before touching is the step that catches it.
OSHA lists equipment not used as prescribed, missing ground paths and lack of ground-fault protection among the most frequent causes of electrical injuries 5. A sound LOTO program does not fix those, so it works alongside them, not instead of them.
What drives the cost of a LOTO program
We do not list prices. Costs depend on how many machines need written procedures, the number of energy sources per machine, lock and tag hardware, training time for authorized and affected employees, annual inspections, and retraining after changes 1. Equipment that cannot be locked may need new lockable disconnects installed by an electrician.
Businesses can get help through commercial electrical services.
Releasing equipment from lockout
OSHA 1910.147(e) sets the order for restoring energy 1.
- Inspect the work area; remove tools and confirm parts are back in place.
- Make sure all employees are safely clear.
- Notify affected employees that locks and tags are coming off.
- Each lock or tag is removed by the employee who applied it.
- Restore energy and confirm normal operation.
Keeping a LOTO program current
- Inspect each procedure at least annually, by an authorized employee not using it 1.
- Certify each inspection: equipment, date, employees and inspector 1.
- Retrain after job, equipment or procedure changes, or when deviations are found 1.
- Keep training certification with names and dates 1.
- Use standardized, durable locks and tags used only for energy control 1.
Red flags on a job site
- A worker in a machine with no lock on its disconnect.
- One lock for a whole crew with no group procedure.
- Tags used where a lock would fit.
- No zero-energy test before work.
- Equipment restarted without a walk-around.
Stop work if energy is not controlled
Never reach into equipment that is only switched off, not locked and verified. Never remove someone else's lock or tag. If you see equipment that is not locked out, stop and tell a supervisor. Anyone injured by electricity needs 911.
LOTO rules: authority, section and status
OSHA 29 CFR 1910.147, The control of hazardous energy (general industry). Requires an energy control program with written procedures, training and periodic inspections; lockout where possible; standardized devices; the six application steps in (d); release steps in (e); and group and shift-change rules in (f) 1.
Current eCFR text, read on osha.gov 10 October 2026.
OSHA 29 CFR 1910.333(b)(2), electrical lockout and tagging. While employees are exposed to parts of fixed electric equipment or circuits that have been deenergized, the circuits must be locked out, tagged or both. Deenergized parts that are not locked or tagged must be treated as energized 2.
OSHA 29 CFR 1926.417, construction. Controls deactivated during work must be tagged; deenergized equipment must be made inoperative and tagged at all points where it can be energized 3.
These standards apply to employers with existing and new equipment alike. They do not apply to homeowners working on their own homes, which is one more reason home electrical work belongs with licensed electricians who follow these practices.
LOTO vs related safety controls
| Control | Purpose |
|---|---|
| Lockout/tagout | Keep equipment off during service |
| Disconnect switch | The device that is locked out |
| Arc flash PPE | Protection when work must be done live |
| Working clearance | Space to work and escape at equipment |
| Voltage testing | Verifying zero energy before touch |
LOTO myths
- Myth A tag is as good as a lock.
- Reality OSHA requires locks wherever the device can be locked; tags are warnings, not restraints 1.
- Myth Turning off the switch is enough.
- Reality Stored energy and other sources can remain; verification is required 1.
- Myth One lock covers the crew.
- Reality Group lockout requires each worker's personal lock or tag 1.
- Myth LOTO is only for electricity.
- Reality It covers mechanical, hydraulic, pneumatic, chemical and thermal energy too 4.
State OSHA plans
Federal OSHA standards apply across the US, and some states run their own OSHA-approved programs that may add requirements. Electrician licensing, which governs who may do electrical service work, is set by each state. Check both before hiring for commercial work.
What LOTO means for you
If you run a business with machines or electrical equipment, you need a written energy control program under 1910.147 unless an exemption clearly applies. If you hire contractors, ask how they lock out and coordinate with your program; OSHA 1910.147(f)(2) requires outside and on-site employers to inform each other 1.
At home, the lesson is simpler. Hire a licensed electrician, who will turn off and verify circuits before working. Start with our hiring guide.
At home
If an electrician is working in your panel, leave the panel and breakers alone until they say the job is done, even if a room is dark.
Questions about Lockout/Tagout
What is lockout/tagout?
Lockout/tagout is a safety procedure that shuts off and isolates the energy sources of machines or circuits, then secures them with locks or tags so they cannot be restarted while someone works on them. OSHA 1910.147 requires it in general industry.
What are the steps of lockout/tagout?
OSHA 1910.147(d) lists six: prepare for shutdown, shut the equipment down, isolate all energy sources, apply locks or tags, relieve or restrain stored energy, and verify isolation before starting work.
What is the difference between lockout and tagout?
Lockout uses a lock to physically hold an energy isolating device off. Tagout uses a warning tag. OSHA requires lockout wherever the device can be locked; tagout alone is allowed only when it cannot, or when the employer shows equal protection.
Who can remove a lockout device?
The employee who applied it. OSHA 1910.147(e)(3) allows removal by someone else only under a specific, documented employer procedure with the safeguards the standard lists.
How often must LOTO procedures be inspected?
At least annually. An authorized employee other than those using the procedure must inspect it, correct deficiencies and certify the inspection with the equipment, date, employees and inspector.
Does lockout/tagout apply to electrical work?
Yes. OSHA 1910.333(b)(2) requires circuits feeding deenergized fixed equipment to be locked out, tagged or both while employees are exposed. Parts that are not locked or tagged must be treated as energized.
Does LOTO apply to construction?
Construction is excluded from 1910.147 but has its own rule. OSHA 1926.417 requires tagging controls and tagging deenergized circuits at all points where they can be energized.
What is group lockout?
When several workers service the same equipment, each attaches a personal lock or tag, often to a group hasp or lockbox, under one responsible authorized employee. Power cannot be restored until every worker removes their own lock.
What training does LOTO require?
Authorized employees learn to recognize energy hazards and isolate them. Affected employees learn the purpose and use of the procedure. Other employees learn not to restart locked or tagged equipment. Retraining follows changes or deviations.
Do homeowners need to follow lockout/tagout?
OSHA rules apply to employers, not homeowners. The principle still matters: never work on wiring that is only switched off. Hire a licensed electrician, who will isolate and verify circuits before working.
Sources
- OSHA, 29 CFR 1910.147 The control of hazardous energy (lockout/tagout), retrieved .
- OSHA, 29 CFR 1910.333 Selection and use of work practices, retrieved .
- OSHA, 29 CFR 1926.417 Lockout and tagging of circuits (construction), retrieved .
- OSHA, Control of Hazardous Energy (Lockout/Tagout) topic page, retrieved .
- OSHA, Electrical safety and health topic page, retrieved .
Expert review
Written by the HyreElectrical Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: All requirements read from the regulatory text of OSHA 1910.147, 1910.333 and 1926.417 and OSHA's hazardous energy topic page on osha.gov, 10 October 2026. The procedure example is illustrative. Held for review by a qualified safety reviewer before indexing.
Suggest a correction. We fix errors and say what changed.