Lockout Tagout Procedure: 8 Steps With a Press Example

What is a lockout tagout procedure

A lockout tagout (LOTO) procedure isolates every energy source of a machine, locks each isolating device with a personal padlock and marks it with a tag before anyone works on the equipment. It prevents unexpected start-up and the release of stored energy while someone is inside the machine.

Pressing the stop button is not enough. A switched-off press can still hold pressure in its accumulator, the ram can drop under gravity, and a colleague can close the breaker without knowing a technician is inside. LOTO answers this with a fixed, verifiable sequence.

Lockout tagout visual map

The map summarizes the sequence of isolation, lock, verification and release, using the hydraulic press example from this article.

Which energy sources to isolate

The most common mistake is to think only of electricity. Before writing the procedure, list every energy source on the machine, including stored energy:

• Electrical: main supply, auxiliary control circuits and capacitors.
• Hydraulic and pneumatic: pressure in lines, cylinders and accumulators.
• Mechanical and gravitational: flywheels coasting down, compressed springs and suspended parts.
• Thermal and chemical: steam, hot oil, product in the piping.

Each source becomes an isolation point with its own label on the machine (for example, "Q1 – main breaker") and an instruction for bleeding off residual energy. A preliminary risk analysis helps decide which tasks need LOTO and which are covered by interlocked guards, as in machine safety without slowing production.

The 8 steps of lockout tagout

1. Prepare: identify the machine, its energy sources and isolation points on the lockout sheet.
2. Notify operators and neighboring areas about the shutdown.
3. Shut down using the normal machine controls.
4. Isolate each source: open the breaker, close the valve, disconnect.
5. Lock and tag: personal padlock and a tag with name, date and reason on every point.
6. Release stored energy: bleed, purge, block suspended parts.
7. Verify: test for absence of voltage with a suitable instrument, check gauges at zero and attempt a start from the controls (try-out).
8. Do the work and then release: remove tools, refit guards, notify the team, each person removes their own lock, then re-energize.

Step 7 separates real LOTO from paper LOTO: without verification, the padlock only proves that a breaker was opened, not that the machine is safe.

Example: hydraulic press (fictional case)

Replacing a cylinder seal on a hydraulic press. The lockout sheet lists five isolation points:

Three mechanics enter the machine. The authorized employee places 5 locks on the isolation points and keeps the keys in a group lock box; each mechanic then closes a personal lock on the box (3 locks). Total: 5 + 3 = 8 locks. The machine can only be re-energized when all three have removed theirs.

The time cost and how to reduce it

If each lockout takes 12 minutes and the press is stopped 4 times a week for intervention, that is 12 × 4 = 48 min per week, or 48 × 52 = 2,496 min = 41.6 hours per year. This is the price of safety, and the answer is not skipping steps but cutting the waiting time:

• Group the isolation points on one clearly labeled panel.
• Keep the lockout sheet laminated on the machine itself.
• Keep padlocks, tags and lock boxes on a shadow board next to the equipment, as in 5S.
• Treat LOTO as part of shutdown planning, alongside the maintenance plan, not as last-minute paperwork.

Rules that hold the program together

• Personal lock: each person has their own, with the only key in their pocket. A borrowed lock defeats the system.
• Tag: must show name, date and reason; on its own it is only a warning and cannot stop a start-up.
• Shift change: the outgoing shift keeps its lock on until the incoming shift applies theirs.
• Removing an abandoned lock: only through a formal procedure, with the owner located and the area checked.
• Training and retraining: authorized employees (who lock out) and affected employees (who operate or walk by) need different training. See how to write the instructions in a standard operating procedure.
• Periodic audit: sample the lockout sheets and follow up on autonomous maintenance, where operators also work on the machine.

LOTO fits the safety management described in ISO 45001 as an operational control for an identified hazard.

Common mistakes

• Locking out only electrical energy and forgetting hydraulic, pneumatic and gravity.
• Skipping the try-out and the zero-energy verification.
• Using a tag alone where the device accepts a padlock.
• Sharing padlocks or leaving the key on the panel.
• A generic lockout sheet that does not say where each point is.
• Adjusting a running machine without a risk assessment: tasks that need the machine energized require a different protective measure.

Frequently asked questions

What does LOTO stand for?

Lockout/tagout: padlocking the devices that isolate energy and tagging them so the machine cannot start during maintenance.

Can a tag replace a lock?

No. A tag warns but does not prevent energization. Use a padlock whenever the device can take one.

Who can remove a lock?

Only the person who applied it. If it is forgotten, only through a formal procedure, with the owner located and the machine verified.

How many locks does a group job need?

One on each isolation point, with the keys in a lock box, plus each person's personal lock on the box. In the example, 5 + 3 = 8.

Is LOTO only for electricity?

No. It covers all hazardous energy: electrical, hydraulic, pneumatic, mechanical, gravitational, thermal and chemical.

What is a try-out?

It is attempting to start the machine from its controls after lockout, to confirm nothing moves, before anyone enters the danger zone.

About the author

Vagner Soares

Lean Manufacturing & Behavioral Management Specialist

Over 20 years in the automotive and metalworking industries (GM and Dana), Lean Manufacturing practitioner since 2006. SENAI instructor and mentor in Brazil’s Brasil Mais Produtivo program, delivering consulting, training and audits for 50+ companies, combining quality, productivity and people development.

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