Lockout/Tagout (LOTO) is the protocol that prevents the unexpected start-up of equipment or machinery during service or maintenance procedures. 


Lockout Devices

Lock machinery with a key or combination lock to block potential hazardous energy release.


Tagout System

Alerts workers and others in the area that they may not use or operate equipment until authorized personnel remove the warning.

View more terms and definitions for Lockout/Tagout.


What is Hazardous Energy and How is It Controlled?

Hazardous energy is any power source that poses a potential danger to workers.
Failure to effectively manage stored energy within machines can cause an unexpected release of power.

Lockout is the most reliable method to protect workers from dangerous power sources.
The use of a lockout device puts systems in a zero energy state, eliminating the potential hazards of stored energy. 

What Must an Energy-Control Procedure Include?

Procedures for hazardous energy management must detail the following components:

  • The scope of the process
  • The purpose of the steps
  • The required practices
  • The personnel authorized to execute the procedures
  • The methods used to ensure safety and compliance
  • The devices needed to control the energy sources

What are OSHA's Requirements for LOTO?

OSHA requires safety procedures to isolate the machinery from all power sources, preventing the release of potentially hazardous energy.

General Industry 29 CFR 1920.147:

This section states that employers must establish a plan and employ systems that protect workers when repairing machinery. This standard involves attaching suitable energy-isolating lockout and tagout devices to equipment, preventing stored energy from discharging suddenly.

Construction 29 CFR 1926.417:

This regulation states that workers must appropriately tag all deactivated controls during maintenance tasks to warn and inform others of the process.

OSHA Lockout/Tagout Color Codes

OSHA does not require specific color codes for LOTO, but below are their recommendations:

Warning (Orange)

Caution (Yellow)

Danger (Red)

Bio Hazards (Fluorescent Orange)

5 Elements for Complete Lockout/Tagout OSHA Compliance

  1. LOTO program with detailed policies and systems
  2. Training programs for all relevant employees and managers
  3. Documentation of lockout/tagout procedures
  4. Lockout/tagout devices to ensure safety
  5. Annual review of LOTO program

Who is Responsible for LOTO?

A designated person at the facility is responsible for organizing and implementing all energy control procedures. However, all affected employees must be trained on the necessary processes and tasks involved with LOTO safety procedures.


When should you use lockout?

Workers must use LOTO procedures under the following circumstances:

  • The equipment requires repair, cleaning or service.
  • Operators must work near the hazardous areas of the machinery.
  • Someone must set up or install new equipment.
  • A worker needs to replace a machine part.
  • A supervisor must perform an equipment inspection.


Can you use tagout devices instead of lockout tools?

Tagout should rarely be used by itself, it does not provide the safety of lockout. Tags are warning systems and do not stop the energization of equipment.
If an employer can prove that a tagout fully protects workers or there is no place to position a lockout device on the machine, you can use a tagout method without a lock.

What do you do before starting service or maintenance activities?

Before anyone begins work on a locked-out or tagged-out machine, an authorized employee must verify that the equipment's power sources are isolated correctly. They must also confirm there is no remaining stored energy within the system.

What do you do before removing lockout or tagout devices and re-energizing machines?

The OSHA standard requires the following:

  • An authorized employee must inspect the machinery to ensure all components are operational and unimpaired.
  • The same employee who attached the lockout and tagout devices removes them from the equipment.
  • The employee informs workers that the lockout/tagout methods have been removed and asks them to clear the area.

What if you need power to test or position equipment?

If testing the machinery requires energy, all employees must clear the area during the inspection. If workers must remain near the equipment to complete the test, employers must use alternate safety measures, such as:

  • Plexiglass barriers
  • Cameras
  • Employee restraints
  • Two-hand control devices

Lockout Tagout Program Steps

  1. Develop a comprehensive, written lockout/tagout program. Detail the specific steps for each type of equipment and procedure.
  2. Locate and label all energy isolation points with permanent tags.
  3. Train all affected employees, authorized personnel and workers in the area of hazardous machinery to know and carry out safety procedures.
  4. Utilize secure lockout/tagout devices.
  5. Perform regular reviews of the LOTO program and make adjustments as necessary to maintain optimal safety.

Lockout Tagout Device Definitions and Uses:

Cable Lockouts: A versatile device with a long cable that goes around various isolating components and secures with a padlock.

Chain Lockouts: Chains offer a way to keep people out of large areas that need to be locked out.

Circuit Breaker Lockouts: Electrical isolation locks for circuit breakers.

Energy Source Identification: Identify equipment names and energy sources with safety tags.

Hasps: These devices lock out a single energy control on electrical equipment and machines.

Lock Boxes: Safety devices for ensuring lockout keys are not accessible until workers complete all tasks.

Lockout Center Boards: Store LOTO supplies in one place to ensure compliance with safety protocol.

Lockout Documentation: Training forms, booklets, binders and other documentation to explain proper procedures.

Lockout Kits: These collections provide access to necessary safety devices and tools.

Lockout Training: Booklets to supplement your training program and remind workers of LOTO processes.

Padlocks: Trained team members attach these by hand to secure lockout devices.

Plug Lockouts: These tools stop electric currents from energizing machinery by preventing plugs' insertion into a wall outlet.

Security Seals: Tamper-evident seals to add an extra layer of security.

Switch Lockouts: Removable rotary or push-button switch covers to prevent access to controls.

Valve Lockouts: A lockout device to secure the operational portion of a valve.

Worksite Lockouts: These items warn people of dangers and prevent unauthorized access to specific areas.

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