LOTO Procedure Steps: A Safety Manager's Checklist

Key takeaways

• LOTO procedure steps must be documented, specific to each machine, and posted where workers can access them before service begins.
• Energy sources—electrical, hydraulic, pneumatic, mechanical, thermal, and chemical—must be identified, isolated, and locked out before any maintenance work.
• Verification (lockout testing) after isolation and before work resumes is the step that prevents most serious injuries and is often rushed.
• Trained personnel must stay present and responsible for the padlock or lockout device throughout the service window.

Why lockout tagout procedure steps matter

Unexpected machinery startup kills or seriously injures workers on discrete manufacturing floors every year. Most of these incidents happen during maintenance, repair, cleaning, or unjamming—tasks that require someone to work on or inside a machine while it is de-energized. A documented, clear lockout tagout procedure is the legal and practical barrier between a routine maintenance job and a life-changing accident.

OSHA requires every employer with machines that can cause injury through unexpected startup to have a written energy control program. That program must include lockout tagout procedure steps for each affected machine. This is not a suggestion. Your EHS team and plant management are responsible for enforcing it.

The six core steps of lockout tagout procedure

Step 1: Prepare the machine and notify affected workers

Before anyone touches a lock, inform all workers who use or depend on the machine that service is about to begin. Post signage. If the machine is part of a production line, coordinate with operators downstream. Shut down the machine through its normal control sequence—do not skip this step even though the machine is about to be locked out. Normal shutdown clears buffers, reduces pressure in hydraulic lines, and lets any moving parts come to rest naturally.

Step 2: Identify all energy sources

This is where many procedures fail. Workers focus on the obvious electrical disconnect and miss compressed air, residual hydraulic pressure, springs, gravity, or thermal energy stored in the machine. Your procedure must list every energy source for that specific machine. For a punch press, that includes electrical power, air pressure in accumulators, and stored mechanical energy in springs. For a conveyor, it is electrical power, and possibly pneumatic solenoid valves. Do not use a generic procedure. Each machine is different.

Step 3: Isolate each energy source

Turn off or close each energy source at its point of isolation. Electrical: use the main disconnect switch on the machine or the panel. Hydraulic: close isolation valves, then bleed pressure from lines and accumulators. Pneumatic: shut off the supply valve and bleed the system. Mechanical springs: restrain or support them so they cannot suddenly release. Thermal: allow the machine to cool if heat is a hazard. Each isolation point must have a lockout hasp or a location where a padlock can be applied.

Step 4: Apply locks and tags

Apply one lock per energy source at the point of isolation. Each lock must be keyed differently or use a master key managed only by authorized personnel. Attach a tag to every lock that identifies the person who applied it, the date, and the work being performed. Use locks, not tape, chains, or rope. Use tags, not just the lock alone—the tag communicates intent and responsibility. No two workers should share a lock on the same machine during service.

Step 5: Verify isolation (lockout testing)

This is the verification step, and it is the one most often skipped or rushed. After all locks are applied, attempt to start the machine using its normal controls. The machine must not start. Then physically test each energy source to confirm it is truly isolated. For electrical, use a voltmeter on the motor leads. For pneumatic, listen for any hiss or check a pressure gauge. For hydraulic, manually actuate the control lever and confirm no movement occurs. This step confirms that your isolation is real, not assumed. Document this verification—your procedure must state who performed it and when.

Step 6: Remove locks and return the machine to service

When maintenance is complete, the person who applied the lock must be present to remove it. If that person is not available, management must follow your procedure for lock removal in their absence. Never cut a lock that belongs to another worker without their knowledge. Reverse the isolation steps—open manual isolation valves, restore air pressure, reconnect electrical supplies. Ensure no tools, parts, or workers are inside or near the machine. Notify all affected workers that the machine is about to be returned to service. Test the machine under no-load conditions first, then under normal operation. Resume production only when the machine runs normally.

Making your lockout tagout procedure work in practice

A procedure written but never used is just a document. Your EHS team should:

• Post the procedure at the machine or make it instantly accessible on-site. LOTO and point-of-work safety are most effective when workers can reference the steps without delay or memory reliance.
• Train all maintenance and service personnel every year on the procedure for each machine they work on. Include hands-on practice with locks, tags, and isolation valves.
• Conduct a lockout audit twice a year. Observe a technician performing the procedure and verify that every step is followed in order.
• Keep a log of every lockout event: who locked it, when, which machine, which energy sources, and how long the service took. This log helps you spot trends and refine your procedures.

Digital tools can strengthen your LOTO program

Procedures posted on a wall in the maintenance shop do not reach every worker, especially on plants with multiple buildings or shifts. Some plants are now using QR and NFC tags on machines themselves so that any worker can scan and instantly see the lockout procedure for that asset, without searching a binder or waiting for a document. This approach eliminates the excuse "I didn't know the procedure" and gives night-shift or contract workers the same access to current, accurate information as full-time staff.

Next steps

Review your current lockout tagout procedures with your maintenance team and EHS staff. Verify that each procedure is specific to the machine, lists all energy sources, and includes a verification step. Conduct a training session on the procedure for at least one high-risk machine. If you manage multiple facilities or machines, consider how workers access the procedure on-site. AssetEngine can help you make procedures instantly available at the point of work—let us show you how.

@@@END@@@