LOTO Standards Explained: OSHA 1910.147, ANSI Z244.1, and What Actually Applies in 2026

How lockout/tagout requirements work for manufacturing plants, fabrication shops, and contractor crews

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A Lock Only Protects the Person Who Hung It

LOTO standards are some of the most cited rules in American industry. Lockout/tagout ranked #4 on OSHA’s Top 10 Most Frequently Cited Standards for FY2025, and it’s been on that list for years.

Having locks isn’t usually the problem, and neither is having a written program. The citations and the injuries come from the gaps between the paperwork and the job: a procedure that doesn’t match the machine, a crew that doesn’t verify zero energy, a shift change where nobody owns the isolation.

If you’re a safety manager, operations manager, or shop owner trying to figure out which LOTO standard actually governs your work — OSHA 1910.147, the construction rules in 1926, ANSI/ASSP Z244.1, or ISO 45001 — this guide lays out what each of these lockout/tagout standards requires and where programs break down.

From the Floor: I was managing a coatings project inside a food processing plant when the whole plant shut down mid-morning: a welder had cut into a nitrogen line that was back under pressure. The last welder on second shift had pulled his lock, the line was put back in service overnight, and first shift walked in assuming it was still isolated — nobody hung a new lock or verified zero energy before the torch came out. That welder went to the hospital with critical injuries. When the plant’s maintenance manager, my contact for the project, walked me through what happened, one thing stood out to me: the problem wasn’t missing equipment. It was an inexperienced crew treating someone else’s lockout as their own.

👉 Before your next job start or shift change, check whether your energy control program would have caught that gap. The free Construction Compliance Checklist walks through 81 jobsite items — including hazardous energy control, contractor coordination, and OSHA 1926 requirements — so you can find the holes before an incident or an inspector does. Download the Construction Compliance Checklist →

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In This Guide

• Which LOTO standards apply to general industry, construction, and contractor work
• The core OSHA 1910.147 program requirements and the six-step application sequence
• Shift changes, group lockout, and outside contractors — where programs fail
• The exceptions crews misread (minor servicing, cord-and-plug, hot tap)
• What ANSI/ASSP Z244.1-2024 adds beyond OSHA — and where A10.44 takes over for construction
• Where OSHA’s LOTO modernization rulemaking stands in 2026
• How LOTO fits inside an ISO 45001 safety management system
• A quick LOTO audit checklist and FAQs

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Quick Answer: Which LOTO Standard Governs What?

Your Situation	Standard That Applies	Notes
Servicing or maintaining machines in a plant or shop	OSHA 1910.147	Mandatory; machine-specific procedures, training, annual inspections
Electrical work on exposed conductors	OSHA 1910.333 (Subpart S)	A 1910.147 program can cover it with two added electrical provisions
Construction work on electrical circuits	OSHA 1926.417	Tags required; written around electrical energy only
Construction or demolition crews (best practice)	ANSI/ASSP A10.44-2020	Voluntary; fills the non-electrical gap in 1926
Plant and shop programs (best practice)	ANSI/ASSP Z244.1-2024	Voluntary; adds alternative methods and risk assessment
Managing energy control inside a safety system	ISO 45001:2018	Voluntary; certifiable management system layer

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👉 Start Here (Top Resources)

• The consensus standard behind best-practice LOTO programs: ANSI/ASSP Z244.1 — The Control of Hazardous Energy covers lockout, tagout, and alternative methods, including the risk assessment process OSHA’s rule doesn’t spell out. Use code CC2026 for 5% off through December 31, 2026 via the ANSI coupon link.
• Managing confined space entries and energy isolation together? The ANSI/ASSP Z244.1 / ANSI B11.19 — Hazardous Energy Safeguarding Package — ANSI Webstore pairs the LOTO standard with the confined space standard at package pricing.
• Running automated equipment or machine cells? The ANSI/ASSP Z244.1 / ANSI B11.19 — Hazardous Energy Safeguarding Package — ANSI Webstore pairs LOTO with the machine safeguarding standard.
• Contractor crews doing construction or demolition work? ANSI/ASSP A10.44-2020 — ANSI Webstore is the construction-specific LOTO consensus standard.

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Which LOTO Standards Actually Apply to Your Work?

The answer depends primarily on what kind of work is being done, not simply on whether the employer calls itself a manufacturer, contractor, or fabricator.

A fabrication shop servicing its own press brake is under general industry rules. The same shop’s field crew doing a tie-in at a refinery turnaround may fall under construction rules. A contractor maintaining equipment inside a host plant may be working under the host’s program and its own at the same time.

Standard	What It Covers	Legal Status
OSHA 29 CFR 1910.147	Servicing and maintenance of machines and equipment in general industry	Mandatory (federal law)
OSHA 1910.333 (Subpart S)	Electrical work on or near exposed conductors and circuit parts	Mandatory; a 1910.147 program can cover it if it meets two added electrical provisions
OSHA 1926.417	Lockout and tagging of electrical circuits in construction	Mandatory for construction work
OSHA 1926.702(j)	Lockout/tagout for concrete and masonry equipment	Mandatory for that equipment in construction
ANSI/ASSP Z244.1-2024	Lockout, tagout, and alternative methods for installing, setup, troubleshooting, servicing, and other covered activities; construction and demolition covered by A10.44 are excluded	Voluntary consensus standard
ANSI/ASSP A10.44-2020	Control of energy sources for construction and demolition operations	Voluntary consensus standard
ISO 45001:2018	Safety management system framework that energy control plugs into	Voluntary; certifiable

⚠️ 1910.147 does not apply to construction work. The general industry standard specifically excludes employment covered by 29 CFR 1926. That catches contractors off guard — and the construction rule that does apply, 1926.417, is written around electrical circuits and allows tags where general industry would require a lock.

OSHA’s Control of Hazardous Energy overview lists the related standards for maritime, construction, and state-plan programs.

For a deeper look at how the OSHA and ISO systems relate, see OSHA vs. ISO Frameworks and ISO 45001 vs OSHA 1910.

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OSHA 1910.147: What the Standard Actually Requires

The general industry standard requires a three-part energy control program: written procedures, employee training, and periodic inspections. Every citation traces back to one of those three pieces or to how the procedure was applied on the floor.

Machine-Specific Energy Control Procedures — 1910.147(c)(4)

Procedures must be developed, documented, and used for the control of hazardous energy on each machine or piece of equipment. Each one must spell out the scope, steps for shutting down and isolating, steps for placing and removing locks, and how to verify that the energy is actually controlled.

Common finding in practice: a single corporate LOTO policy covering every machine in the building. A policy is not a procedure. The inspector wants to see the steps for the press in bay four, including the pneumatic dump valve and the counterweight — not a generic “turn off power, apply lock.”

There’s one narrow exception: a written procedure isn’t required when the equipment meets all eight conditions in 1910.147(c)(4)(i) — a single energy source, no stored energy, a single lockable isolation point, exclusive control by the authorized employee, and no accident history, among others. In my experience, few machines in a fabrication shop qualify.

Lockout vs. Tagout — 1910.147(c)(2) and (c)(3)

If an energy isolating device can accept a lock, 1910.147 generally requires lockout — unless the employer can demonstrate that tagout provides full employee protection equal to lockout. Tagout alone is also used where the device physically can’t accept a lock. Since January 2, 1990, new machines and equipment, along with machines undergoing replacement, major repair, renovation, or modification, must have energy isolating devices designed to accept a lockout device.

Training — 1910.147(c)(7)

The standard separates three groups of people:

• Authorized employees — the people who apply locks and perform the servicing. They need training in recognizing hazardous energy sources, the type and magnitude of energy, and the methods to isolate it.
• Affected employees — operators and others who work on or near the equipment. They need to know the purpose of the procedure and to never try to restart locked-out equipment.
• Other employees — anyone who might be in the area. They need to understand the prohibition against restarting.

Retraining is required when job assignments, equipment, processes, or procedures change — or when a periodic inspection shows someone doesn’t know the procedure.

Periodic Inspection — 1910.147(c)(6)

At least annually, an authorized employee other than the ones using the procedure must inspect each energy control procedure and certify the inspection in writing. A common finding in practice: the inspection is either skipped, done as a paperwork review with no observation, or documented without identifying the equipment, the date, and the employees included.

The Six-Step Application Sequence — 1910.147(d)

Step	Requirement	Where It Fails on the Floor
1. Preparation	Authorized employee knows the energy types, magnitude, and hazards	Worker unfamiliar with the machine skips the procedure
2. Shutdown	Machine is shut down using the normal procedure	Emergency stop used as the “isolation”
3. Isolation	All energy isolating devices operated	Secondary sources missed — pneumatics, gravity, backfeed
4. Lock/tag application	Each authorized employee applies a lock or tag	One lock for a whole crew
5. Stored energy	Residual energy relieved, disconnected, or restrained	Accumulators, springs, capacitors, and pressurized lines not bled
6. Verification	Isolation and de-energization verified before work starts	“Try” step skipped because the lock is already on

Step 6 is the one that would have stopped the injury in my story. A welder who verified zero pressure before cutting would have found a live line.

If you’re dealing with the guarding side of the same equipment, Machine Guarding Standards covers where guarding stops and energy control starts.

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The Three Situations Where LOTO Programs Break

A program that works fine on a routine job with one mechanic and one machine can break down when the job gets bigger, longer, or involves more than one employer. OSHA addresses all three situations in 1910.147(f) — and these paragraphs are the ones crews are least likely to have read.

Shift and Personnel Changes — 1910.147(f)(4)

The standard requires specific procedures during shift or personnel changes to keep lockout protection continuous, including an orderly transfer of lockout devices between off-going and oncoming employees.

The key word is orderly. The off-going worker doesn’t pull his lock and go home. The oncoming worker applies his lock first, then the off-going worker removes his. At no point is the equipment left without a lock from someone who is actually exposed.

That’s exactly what didn’t happen at the food plant. Second shift’s last lock came off, the line was put back in service, and first shift assumed a lockout that no longer existed.

Group Lockout — 1910.147(f)(3)

When a crew services equipment together, the standard requires a level of protection equivalent to each worker applying a personal lock. The common tools are a group lockbox (the primary authorized employee locks the isolation points and puts the keys in a box; every crew member adds a personal lock to the box) or a multi-lock hasp on each isolation point.

Either way, the principle is the same: every exposed worker hangs a personal lock, and nobody removes a lock that isn’t theirs. One lock for a whole crew is not group lockout.

Outside Contractors — 1910.147(f)(2)

When outside servicing personnel work in your facility, the host employer and the contractor must inform each other of their energy control procedures, and the host must make sure its own employees understand and follow the contractor’s program.

If you are a contractor working inside a general-industry plant → get the host’s LOTO procedure for the specific equipment in writing before your crew touches it, and agree on who controls isolation at shift change.

If you are the host employer bringing in contractors → treat the pre-job LOTO briefing as a documented step, not a hallway conversation. That contractor coordination can also support the requirements of ISO 45001 clause 8.1.4, particularly where the host and contractor share responsibility for controlling operational risks.

👉 Group lockout and contractor handoffs are exactly where field crews and host plants lose track of who’s protected. The Construction Compliance Checklist includes contractor management and hazardous energy items you can run before your next mobilization. Get the checklist and run it before your next job start →

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The Exceptions Crews Misread

1910.147 has exceptions. They’re narrow, and each one has conditions that crews tend to drop.

Exception	What It Actually Allows	The Condition People Skip
Minor servicing during normal production	Routine, repetitive tasks integral to production (e.g., minor tool changes) without full LOTO	Only if alternative measures provide effective protection — not just “it’s quick”
Cord-and-plug equipment	Unplugging instead of locking out	The plug must be under the exclusive control of the employee doing the work
Hot tap operations	Work on pressurized pipelines when shutdown is impractical	Continuity of service must be essential, shutdown impractical, documented procedures followed, and special equipment used

The hot tap exception deserves attention in any shop that does pipe work. It is not a general permission to work on a live line. It applies only to transmission and distribution systems for substances such as gas, steam, water, or petroleum products, and only when continuity of service is essential, shutdown is impractical, and documented procedures and special equipment provide proven effective protection. A welder who cuts a line he believes is dead — and it isn’t — is not doing a hot tap. He’s doing unprotected work on live equipment.

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LOTO in Construction and Field Work

OSHA’s construction requirements for lockout and tagging are narrower than the general industry framework. That doesn’t make field work safer.

29 CFR 1926.417 requires that controls deactivated during the work be tagged, and that de-energized equipment or circuits be rendered inoperative with tags at every point where they can be energized. It is written around electrical circuits. It doesn’t give a field crew a framework for hydraulic, pneumatic, gravity, thermal, or pressurized-process energy — the energy that shows up during tie-ins, commissioning, demolition, and turnaround work.

That’s why many experienced contractors choose to run a general-industry-level program for field crews anyway. Two consensus standards help fill the gap:

• ANSI/ASSP A10.44-2020 — Control of Energy Sources (Lockout/Tagout) for Construction and Demolition Operations. It’s written specifically for contractors. ANSI/ASSP A10.44-2020 — ANSI Webstore
• ANSI/ASSP Z244.1-2024 — its scope covers activities such as erecting, installing, constructing, repairing, testing, troubleshooting, servicing, and maintaining machines, equipment, and processes. However, construction and demolition operations covered by A10.44 are outside Z244.1’s scope.

For companies that run both shop and field crews, Z244.1 and A10.44 work best as complementary standards — Z244.1 for the shop and plant-maintenance side, A10.44 for construction and demolition work — rather than one universal LOTO standard.

If you’re building out a broader construction safety library, the ANSI/ASSP A10 Construction Package bundles the A10 series — scaffolding, fall protection, cranes, and more — at a package discount.

For how shop and field programs should differ, see Building a Safety Management System That Works in the Shop and the Field. Energy isolation also runs straight into hot work permits and confined space entry — the three almost always show up on the same job.

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ANSI/ASSP Z244.1-2024: What It Adds Beyond OSHA

OSHA 1910.147 sets mandatory requirements for hazardous energy control in general industry. ANSI/ASSP Z244.1-2024 provides a broader consensus framework for controlling that energy, including lockout, tagout, and alternative methods — and it’s been updated far more recently than OSHA’s rule.

ASSP publishes an overview of the standard on its Z244.1 standards page.

The 2024 edition presents three distinct approaches to controlling hazardous energy: lockout, tagout, and alternative methods. It also added a new section on hazardous energy control methods and a structured methodology for when full isolation isn’t practical.

Topic	OSHA 1910.147	ANSI/ASSP Z244.1-2024	Key Difference
Legal status	Federal regulation	Voluntary consensus standard	OSHA is enforceable; Z244.1 is best practice OSHA can reference
Scope	Servicing and maintenance, general industry	Installing, setting up, troubleshooting, servicing, maintaining, and other covered activities; construction and demolition covered by A10.44 are excluded	Z244.1 lists covered activities more broadly; construction and demolition go to A10.44
Alternative methods	Narrow minor-servicing exception	Structured risk-assessment process for alternatives when lockout isn’t practical	Z244.1 provides a structured risk-assessment framework
Control-circuit devices	Push buttons and selector switches not accepted as isolation	Addressed through alternative methods with risk assessment	Relevant to modern automated equipment
Edition date	Original rule 1989; effective January 2, 1990	2024	Z244.1 reflects current control technology

⚠️ Z244.1 does not replace OSHA 1910.147. Where OSHA’s regulation applies, a company can’t use a Z244.1 risk assessment to disregard a mandatory OSHA requirement — falling short of 1910.147 can still earn a citation. Use it to build a stronger program, not to argue your way out of the federal rule.

The ANSI/ASSP Z244.1-2024 PDF lists at $144 on the ANSI Webstore — and code CC2026 takes 5% off through December 31, 2026. ANSI Webstore also serves international buyers and offers many standards in multiple languages, which matters for multinational plants standardizing one LOTO program across sites.

If your LOTO program covers automated equipment or machine cells, pairing Z244.1 with the machine safeguarding standard usually makes more sense than buying them separately: ANSI/ASSP Z244.1 / ANSI B11.19 — Hazardous Energy Safeguarding Package — ANSI Webstore. For broader coverage, the ANSI B11 machine safety collection and ANSI’s standards bundle packages save meaningfully compared to buying titles one at a time.

For a full buying walkthrough, see Buy ANSI Safety Standards: Where to Purchase A10, Z359, Z244.1, and PPE Titles.

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Where Lockout/Tagout Standards Are Heading in 2026

OSHA is working on modernizing 1910.147. According to the Department of Labor’s regulatory agenda, the agency plans to publish a proposed rule (RIN 1218-AD00) by November 2026.

The main driver is technology. The current rule doesn’t accept push buttons, selector switches, and other control-circuit devices as energy isolation — a position that conflicts with how modern computer-controlled safety systems are designed. The proposal is expected to address when control-circuit-type devices could be used.

Two practical points while the rulemaking plays out:

• The existing 1910.147 requirements remain in effect unless and until OSHA publishes a final rule that changes them. A proposed rule does not itself change the current standard.
• Regulatory agenda dates slip. Build your program to the current rule and to Z244.1-2024, and watch for the proposal and its comment period.

The Standards Navigator will cover the proposed rule when it publishes.

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Where ISO 45001 Fits

ISO 45001:2018 doesn’t contain LOTO requirements. It gives you the management system that keeps a LOTO program from decaying.

ISO 45001 Clause	How It Applies to Energy Control
6.1.2 — Hazard identification	Hazardous energy sources identified per machine and per task
7.2 — Competence	Authorized and affected employee training tracked and refreshed
8.1.2 — Hierarchy of controls	Isolation and engineering controls ahead of tags and administrative measures
8.1.4.2 — Contractors	Host/contractor energy control coordination planned and verified
9.1 / 9.2 — Monitoring and internal audit	Periodic inspections feed audit evidence and trend data
10.2 — Incident, nonconformity, corrective action	LOTO near-misses investigated to root cause

The 1910.147 annual periodic inspection is already a built-in monitoring activity. In an ISO 45001 system, those inspection results become audit evidence — and a failed inspection becomes a nonconformance with a corrective action, not just a retraining note in a file.

If you are already running ISO 45001 → map your periodic inspection records to clause 9.1 and make sure contractor LOTO coordination shows up under 8.1.4.

If you are building your first safety management system → start with the ISO 45001 Certification Guide and the ISO 45001 documentation requirements.

For internal auditors who need to evaluate energy control against clause requirements, BSI Group’s ISO 45001 training courses and ISOQAR’s ISO 45001 training both cover lead and internal auditor paths.

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“OSHA Is the Law — Why Spend Money on a Voluntary Standard?”

It’s a fair objection. You’re already required to follow 1910.147. Why buy Z244.1?

Three reasons that matter on the shop floor:

• OSHA’s core LOTO rule dates to 1990. It was written before modern automated cells, robotic lines, and safety-rated control systems. Z244.1-2024 gives you a documented method for those situations instead of improvising.
• It goes deeper on the tasks where crews get hurt. Z244.1 spells out covered activities such as installing, setup, troubleshooting, and unjamming in more detail than OSHA’s rule, and adds a structured method for alternatives. For construction and demolition crews, A10.44 is the companion standard.
• The math isn’t close. The Z244.1 PDF lists at $144. The 2026 federal maximum for a single serious OSHA violation is $16,550, and $165,514 for a willful or repeat violation. The Cost of Non-Compliance in Manufacturing breaks down what those penalties look like in practice.

None of that counts the cost of an injury. The food plant incident shut down an entire production facility and put a man in the hospital.

👉 If you can’t say with certainty that every crew verifies zero energy and hands off locks properly at shift change, check it now. The Construction Compliance Checklist gives you a structured self-assessment you can finish before your next job start. Run the checklist before your crew mobilizes →

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Quick LOTO Standards Audit Checklist

✅ Written, machine-specific energy control procedures for every piece of equipment that needs one

✅ Procedures identify every energy source — electrical, pneumatic, hydraulic, gravity, thermal, pressurized process lines

✅ Locks are standardized, durable, identifiable, and used only for energy control

✅ Every authorized employee applies a personal lock — no “one lock per crew”

✅ Group lockout uses a lockbox or multi-lock hasp with personal locks from every exposed worker

✅ Written shift-change procedure for orderly lock transfer — oncoming lock on before off-going lock off

✅ Zero-energy verification (try step) is performed before work begins

✅ Stored energy — accumulators, springs, capacitors, line pressure — relieved or restrained

✅ Contractor and host energy control procedures exchanged before work starts

✅ Annual periodic inspection completed and certified for each procedure

✅ Training records for authorized, affected, and other employees, with retraining after changes

✅ Hot tap work done only under a documented hot tap procedure with proper equipment

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Frequently Asked Questions

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Not Sure What to Do Next?

🔹 Still sorting out which rules apply to your crews? Start with ANSI Safety Standards for Construction and Crane and Rigging Safety Standards to see how the consensus standards fit together, then run the free Construction Compliance Checklist against your current program.

🔹 Ready to tighten up your LOTO program or safety management system? Put your internal auditors through ISO 45001 auditor training with BSI Group or ISOQAR so periodic inspections and contractor handoffs get evaluated as system controls, not checkbox exercises.

🔹 Need the standard itself? Get ANSI/ASSP Z244.1-2024 from the ANSI Webstore — and if you’re also covering confined space, fall protection, or machine guarding, compare ANSI bundle packages or the broader ANSI Safety Standards collection before buying titles individually. Code CC2026 saves 5% through December 31, 2026.

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Lockout/tagout isn’t complicated. Hanging a lock takes seconds. What takes discipline is making sure the right person’s lock is on the right isolation point for the entire time someone is exposed — through shift changes, crew changes, and contractor handoffs. Build your program around those moments — that’s where lockout/tagout standards actually earn their keep — verify zero energy every time, and you’ll close the gaps that put people in the hospital. The Standards Navigator will keep tracking LOTO standards, OSHA’s rulemaking, and the consensus standards that shape real-world energy control.

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The Lock Came Off. The Line Came Back. Nobody Checked.

Organizations that struggle with LOTO treat it as a hardware problem — buy locks, hang a board, write one policy. They find out what’s missing when a crew changes and an assumption fills the gap.

Organizations that get it right plan for the handoff. Every worker’s lock, every shift change, every contractor briefing, and every zero-energy check is written into the procedure and verified in the field.

The Standards Navigator covers the OSHA rules, ANSI consensus standards, and ISO 45001 requirements behind energy control, construction safety, and shop floor compliance — in plain language, from people who have worked under them.

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