A millwright in Saskatchewan was replacing a bearing on a conveyor. Someone had shut the conveyor off but did not lock out the disconnect. A worker in another area restarted the conveyor remotely, not knowing anyone was inside the equipment. The millwright lost three fingers. The investigation found that the company had a lockout/tagout procedure. It was in a binder in the safety office. Nobody on that crew had seen it. Nobody had been trained on it. And the locks were still in their packaging in a drawer.
That is what happens when lockout/tagout is a document instead of a practice. At Safety Evolution, we build safety programs for contractors who want their paperwork to match what actually happens on site. LOTO is one of those topics where the gap between policy and practice kills people.
⚡ Quick Answer
What: Lockout/tagout (LOTO) is a safety procedure for ensuring that hazardous energy sources are isolated and de-energized before maintenance or servicing
Why it matters: Failure to control hazardous energy accounts for roughly 10% of serious industrial accidents and is consistently in OSHA's top 10 most cited violations
The 6 steps: Preparation, shutdown, isolation, lockout/tagout, verify, perform the work
Who needs it: Any worker who performs maintenance, servicing, or works near equipment with stored or active energy
Lockout/tagout (LOTO) is a set of procedures used to ensure that equipment is properly shut down, isolated from all energy sources, and secured before maintenance or servicing work begins. The "lockout" is the physical lock placed on an energy-isolating device. The "tagout" is the warning tag that identifies who placed the lock and why. Together, they prevent the unexpected startup or release of stored energy that could injure or kill workers.
Most contractors think lockout/tagout is just about electrical energy. "Flip the breaker, you're good." That misconception is responsible for more injuries than any other LOTO mistake. There are multiple types of hazardous energy, and your crew needs to account for all of them:
Energy Type
Source Examples
Construction Example
Electrical
Wiring, motors, generators, batteries, capacitors
Working on temporary power panels
Mechanical
Gears, springs, flywheels, pulleys
Servicing a concrete mixer or saw
Hydraulic
Hydraulic lines, cylinders, presses
Maintaining excavator attachments
Pneumatic
Compressed air lines, air tools, tanks
Disconnecting air compressor lines
Thermal
Steam, hot surfaces, heated materials
Welding equipment, hot asphalt lines
Chemical
Pipelines, tanks, processing equipment
Draining chemical lines during demolition
Gravitational
Suspended loads, elevated platforms
Blocking a raised dump truck bed before working underneath
The blunt truth: if your LOTO procedure only covers electrical isolation, it is incomplete and your workers are exposed. A hydraulic cylinder that is still pressurized can release with enough force to crush a limb. A compressed spring can release with lethal energy. Gravity does not care that the motor is locked out if the load is still suspended.
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The LOTO process is standardized. OSHA (in the US under 29 CFR 1910.147), the CSA Z460 standard in Canada, and provincial OHS codes all follow the same essential sequence. Here are the 6 steps your crew must know:
Step 1: Preparation
Identify every energy source connected to the equipment. This is where most shortcuts happen and most injuries start. Review the equipment's energy isolation points. Identify all forms of stored and active energy. Know which isolation devices control which energy sources.
Step 2: Shutdown
Notify all affected workers that the equipment is being shut down and locked out. Then shut the equipment down using the normal operating procedure. Do not just pull the plug or hit the emergency stop. A controlled shutdown prevents additional hazards from an abrupt stop.
Step 3: Isolation
Physically isolate the equipment from every energy source identified in Step 1. This means opening disconnects, closing valves, bleeding pressure lines, blocking suspended components, and disconnecting all energy feeds. Every. Single. One.
Step 4: Lockout and Tagout
Each worker performing the work places their own lock on each energy-isolating device. One person, one lock, one key. If multiple workers are involved, each worker places their own lock using a multi-lock hasp. The tag identifies who placed the lock, when, and why. The lock is the physical barrier. The tag is the communication.
Step 5: Verify Energy Isolation
This is the step that separates "we think it's locked out" from "we know it's locked out." Attempt to start the equipment using the normal controls. Test circuits with a voltage tester. Check pressure gauges. Verify that suspended loads are blocked. If anything moves, cycles, or shows energy, the lockout is incomplete.
Step 6: Perform the Work
Only after verification is complete can work begin. When the work is finished, the process reverses: remove tools, reinstall guards, verify the area is clear of personnel, and each worker removes their own lock.
The critical rule: only the worker who placed a lock can remove it. No exceptions. Not the supervisor, not the foreman, not the site manager. If someone left for the day with their lock on, there is a specific procedure for that, and it is not "cut it off."
What Are Common LOTO Mistakes on Construction Sites?
Construction sites have unique LOTO challenges that factories and plants do not. Equipment is mobile, energy sources are temporary, and multiple trades share the same space. Here are the mistakes we see most often:
"Someone else locked it out." If you did not place the lock yourself, you are not protected. Every worker performing maintenance or servicing must apply their own lock. Trusting someone else's lock with your life is not a system. It is a gamble.
Using the tag without the lock. A tag is a communication tool. It tells people what is happening. But a tag can be removed by anyone. A tag does not physically prevent equipment from being re-energized. Without the lock, it is decoration.
Not accounting for stored energy. The breaker is off, but the hydraulic cylinder is still pressurized, the capacitor still holds a charge, or the counterweight is still loaded. Stored energy must be dissipated, not just isolated.
Skipping verification. "I flipped the breaker, we're good." Did you try to start it? Did you test the circuit? Verification is the proof. Everything before it is just setup.
No training for affected workers. The person doing the maintenance needs full LOTO training. But the worker in the next bay who might accidentally bump a control also needs to understand what those locks and tags mean and why they must never be removed.
What Are Your LOTO Legal Requirements?
In the United States, OSHA's Control of Hazardous Energy standard (29 CFR 1910.147) is one of the most-cited regulations during inspections. Lockout/tagout violations consistently rank in OSHA's top 10 most-cited standards, with penalties that can reach over $160,000 per willful violation.
In Canada, lockout/tagout is addressed by the CSA Z460 standard ("Control of Hazardous Energy: Lockout and Other Methods") and by provincial OHS codes:
Alberta: OHS Code Part 15 covers managing and controlling hazardous energy
BC: WorkSafeBC Regulation Part 10 covers de-energization and lockout
Ontario: O. Reg. 213/91 (Construction) and O. Reg. 851 (Industrial Establishments) address lockout requirements
The requirements across all jurisdictions share common elements: written procedures for each piece of equipment, training for authorized and affected employees, periodic inspections of the program, and documentation.
If your LOTO program is just a generic template you downloaded and stuck in a binder, it does not meet the standard. Procedures must be equipment-specific. Training must be documented. And inspections must be performed at least annually. If that sounds like a lot to manage, it is. That is why contractors work with Safety Evolution as their done-for-you safety department to build and maintain LOTO programs that actually hold up to an audit.
How Do You Deliver a LOTO Toolbox Talk That Sticks?
Reading the 6 steps out loud is not a toolbox talk. Here is how to make it count:
Bring the hardware. Show up with a lockout hasp, a few padlocks, and a tag. Pass them around. Let people handle the equipment. Physical props make abstract concepts real.
Walk through a real scenario. Pick a piece of equipment your crew actually uses: a table saw, a compressor, a generator. Walk through the LOTO procedure on that specific machine. Where is the disconnect? What energy sources does it have? Where do you put the lock? How do you verify?
Tell the story that makes it real. Every experienced worker knows someone, or knows someone who knows someone, who got hurt because equipment started unexpectedly. Let those stories be told. The best safety lessons come from the crew, not from the person delivering the talk.
Ask the uncomfortable question: "How many of you have ever started work on equipment that was shut off but not locked out?" The honest answers are where the real learning happens.
Lockout/tagout (LOTO) is a safety procedure that ensures equipment is completely shut down, disconnected from all energy sources, and physically locked before anyone works on it. The lock prevents the equipment from being turned back on. The tag tells everyone who locked it and why. It prevents injuries and deaths from unexpected equipment startup.
What are the 6 steps of lockout/tagout?
The 6 steps are: (1) Preparation: identify all energy sources. (2) Shutdown: notify affected workers and shut down using normal procedures. (3) Isolation: physically disconnect all energy sources. (4) Lockout/tagout: each worker applies their own lock and tag. (5) Verification: attempt to restart the equipment to confirm isolation is complete. (6) Perform the work.
Can a supervisor remove another worker's lock?
Not under normal circumstances. Only the worker who placed a lock should remove it. If the worker is unavailable (left the site, absent), both OSHA and Canadian standards allow lock removal under a documented procedure that includes: verifying the worker is not on site, attempting to contact them, inspecting the equipment, and ensuring no one is at risk before removal. This exception must be documented and should never become routine.
Does lockout/tagout apply on construction sites?
Yes. While OSHA's primary LOTO standard (29 CFR 1910.147) applies to general industry, construction sites have their own hazardous energy requirements under 29 CFR 1926 Subpart K (Electrical) and general duty requirements. In Canada, provincial OHS codes and the CSA Z460 standard apply to all workplaces, including construction. Any time workers service or maintain equipment with hazardous energy, LOTO procedures are required.
Where can I get a free lockout/tagout toolbox talk?
Safety Evolution offers a free 52 Construction Toolbox Talks PDF package that includes lockout/tagout, electrical safety, and 50 other essential construction safety topics. Each talk is print-ready with a sign-in sheet.
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