Lockout Tagout Procedure: A Step-by-Step Safety Guide

Every year, hundreds of workers suffer severe injuries—or worse—because machinery was accidentally energized during maintenance. The root cause? A missing or improperly executed lockout tagout (LOTO) procedure. This isn’t just a checklist chore. It’s a lifesaving protocol that, when done right, prevents unexpected startup, uncontrolled release of hazardous energy, and catastrophic workplace incidents.

OSHA reports that proper implementation of a lockout tagout program can prevent up to 120 fatalities and 50,000 injuries annually. Yet, non-compliance remains shockingly common, especially in manufacturing, utilities, and construction. This guide breaks down the full LOTO procedure—not as a generic list, but as a real-world, actionable sequence that protects lives and satisfies regulatory standards.

What Is Lockout Tagout?

Lockout tagout is a safety procedure used to ensure that dangerous machines and energy sources are properly shut off and isolated from power before maintenance or servicing begins. The “lockout” component physically prevents re-energizing equipment using a lock, while “tagout” involves placing a visible warning tag on the energy-isolating device.

While tagout alone can be used in specific cases, lockout is preferred because it provides a physical barrier. Together, they create a standardized method for protecting employees who work on or near hazardous machinery.

When Is LOTO Required?

OSHA standard 29 CFR 1910.147 mandates LOTO whenever employees service or maintain machines or equipment where unexpected energization or startup could cause injury. This includes:

• Replacing belts, blades, or motors
• Clearing jams in production lines
• Performing cleaning inside machinery
• Conducting electrical repairs
• Adjusting mechanical components under tension

If there’s stored energy (mechanical, electrical, hydraulic, pneumatic, chemical, thermal), LOTO isn’t optional—it’s essential.

The 7-Step Lockout Tagout Procedure

Following a structured, consistent sequence is critical. Deviations introduce risk. Here’s the standard, OSHA-aligned LOTO procedure broken into seven essential steps.

Step 1: Prepare for Shutdown

Before touching any equipment, authorized employees must identify all energy sources powering the machine. This includes primary (electrical) and secondary (hydraulic accumulators, springs, gravity-fed systems, etc.).

Example: A conveyor system may run on electricity but also rely on tensioned rollers and gravity feed. All must be accounted for.

At this stage, communicate the shutdown plan to affected employees. They should know when the machine will go offline and why.

Common Mistake: Skipping a secondary energy source. A technician once released a pressurized valve thinking it was safe—only to be hit by a burst of compressed air. Always audit energy types.

Step 2: Notify Affected Personnel

Inform all employees who operate or work near the equipment that a maintenance shutdown is about to occur. This prevents confusion and ensures no one attempts to restart machinery unknowingly.

Use clear communication—verbally announce, post temporary signage, or use intercom systems in large facilities.

Step 3: Shut Down the Equipment

Follow established shutdown procedures. This typically involves stopping the machine via normal stopping controls. Never assume turning off a switch cuts all power.

Pro Tip: Use machine-specific shutdown checklists. Some equipment requires gradual ramp-down to avoid damage or residual energy buildup.

Step 4: Isolate Energy Sources

Locate and operate all energy-isolating devices. This may include: - Main electrical disconnects - Manual valves for fluid systems - Block valves for pneumatic lines - Mechanical blocks for gravity systems

Each energy source must be physically disconnected. Circuit breakers alone are not considered isolating devices unless specifically designed for that purpose.

Real-World Scenario: In a food processing plant, a technician locked out the electrical supply but forgot to close the steam valve. Residual heat caused a scalding injury when a panel was opened. Always double-check isolation.

Step 5: Apply Lockout/Tagout Devices

Each authorized employee must apply their own lock and tag to every energy-isolating device. This is non-transferable—no sharing locks or using master keys.

Locks should be: - Durable and standardized - Identified with the employee’s name, department, and contact info - Paired with a tag stating: - Why the lock is applied - Who applied it - Date and time - Potential hazards

Tags must be legible and withstand workplace conditions (moisture, heat, abrasion).

Best Practice: Use group lockout boxes when multiple technicians work on one machine. Each applies their lock to the box, which holds the actual lockout device. This ensures no single person can restart the system prematurely.

Step 6: Release Stored Energy

Even after isolation, residual energy may remain. This includes: - Capacitors holding electrical charge - Pressurized lines - Flywheels or rotating parts in motion - Springs under tension

Safely dissipate or block this energy using bleeding valves, grounding, restraints, or other engineering controls.

Workaround Trap: Some workers skip this step, believing “it’s low pressure” or “it’s already off.” Stored energy has caused fatal incidents. Always verify zero energy state.

Step 7: Verify Isolation (The

Most Critical Step)

Before any work begins, confirm the machine cannot start. This is done by attempting to restart the equipment using normal operating controls—while standing clear.

If the machine attempts to start or shows signs of energy, stop work immediately. Re-trace isolation steps. This verification step is where many LOTO failures occur.

Example: A maintenance worker bypassed verification on a hydraulic press. The lock appeared secure, but a backup pump briefly energized the system. The press activated mid-adjustment, resulting in crushed fingers.

Only after zero energy is confirmed should work begin.

Common LOTO Procedure Mistakes and How to Fix Them

Even experienced teams make errors. Here are frequent violations and their solutions:

Another widespread issue: complacency. In high-pressure environments, workers skip steps to “save time.” But LOTO isn’t a productivity obstacle—it’s a prerequisite for safe efficiency.

Equipment Used in LOTO Procedures

Effective lockout tagout relies on reliable tools. Here are five essential types and examples:

1. Lockout Hasps
2. Allow multiple locks to be applied to a single isolation point. Example: Brady LOCKOUT HASP 1202, supports up to six locks.

1. Valve Lockouts
2. Secure ball, gate, and butterfly valves. Example: Master Lock 1415T for 1/2” to 2” valves.

1. Circuit Breaker Lockouts
2. Prevent reset of breakers. Example: Grainger 4ZCD6 with universal fit for common panels.

1. Plug Lockouts
2. Used on electrical cords. Example: IDEAL LOTO-PLUG for 120V to 277V outlets.

1. Group Lockout Stations
2. Centralized kits with locks, tags, hasps, and checklists. Example: Seton 90500-KIT, ideal for team maintenance.

Invest in durable, color-coded equipment. Red locks for electrical, yellow for mechanical, green for stored energy—this visual system boosts compliance.

When the LOTO Procedure Ends: Restoration Steps

Re-energizing equipment is just as critical as shutting it down. Follow this sequence:

1. Clear tools and materials from the machine
2. Ensure all employees are clear of the equipment
3. Remove locks and tags—only by the person who applied them
4. Re-energize systems in reverse order of shutdown
5. Notify affected personnel that the machine is operational

Never restart equipment without confirming the area is safe. One incident at an automotive plant occurred when a supervisor restarted a robotic arm—unaware a technician was still inside the cage.

Training and Compliance: Beyond the Procedure

A written LOTO program is required by OSHA. It must include: - Machine-specific procedures - Roles of authorized vs. affected employees - Training schedules - Periodic inspections (at least annually)

Authorized employees (those who perform LOTO) require in-depth training, including hands-on practice. Affected employees (those who operate equipment) need awareness training.

Inspection Tip: During annual audits, watch a technician perform a full LOTO sequence. Note deviations. Correct them immediately with retraining.

Companies that treat LOTO as a ritual rather than a routine see far fewer incidents. One paper mill reduced lockout-related near-misses by 87% after introducing shadow audits and peer reviews.

Final Thoughts: LOTO Is a Culture, Not Just a Procedure

A flawless lockout tagout procedure isn’t just about compliance—it’s about creating a culture where safety overrides speed. Every missing lock, faded tag, or skipped verification erodes that culture.

Implement standardized checklists. Conduct surprise drills. Empower workers to stop work if LOTO isn’t followed. The few extra minutes spent locking out correctly are always cheaper than the cost of an injury.

Start today: audit one machine’s LOTO process. Verify every step. Train one team member. Small actions build resilient systems.

Because when it comes to hazardous energy, the only acceptable incident rate is zero.