Home » Courses » Occupational Safety & Health » Lockout/Tagout


Learning Objectives

  • Recognize the purpose of lock and tag procedures
  • Match roles and responsibilities for worker designations under lock and tag
  • Identify sources of energy hazards and consequences of improper control
  • Recall employer responsibilities and requirements for lock and tag
  • Recognize different types of lock and tag devices
  • Identify basic procedural steps for lock and tag
  • Recognize criteria and situations that qualify as exceptions to lock and tag requirements

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20 minutes

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OSHA estimates that failure to control hazardous stored energy accounts for nearly ten percent of serious accidents in many industries, and workers injured on the job from exposure to hazardous energy lose an average of 24 workdays. But OSHA also states that compliance with lockout and tagout procedures prevents an estimated 120 fatalities and 50,000 injuries each year.

To protect you from the serious hazards posed by the unexpected start-up or operation of equipment during repair or maintenance, the Occupational Safety & Health Administration (OSHA) has established a Control of Hazardous Energy standard. It is commonly referred to as the lockout/tagout (LOTO), or energy isolation standard. This standard requires the application of markings and barriers that prevent unauthorized persons from energizing and operating equipment.  

Energy in any form becomes hazardous when it builds to a certain level, or is released inadvertently or unexpectedly. Lockout/tagout refers to specific practices and procedures that safeguard employees from the unexpected startup of machinery and equipment, or the release of hazardous energy, during service or maintenance activities.

Purpose of Locks and Tags

In addition to ensuring that a machine has been isolated or disconnected from its power source, lock and tag procedures establish safe boundaries to protect workers. Locks and tags serve different purposes, however, and should be used accordingly.

By themselves, tags cannot sufficiently prevent an individual from starting a piece of equipment while another individual is servicing it. Because of this, tags should only act as temporary warnings until the hazardous equipment can be properly locked.

Tags must be securely attached, legible and understandable. They must be made of materials that can withstand the environmental conditions they may encounter, such as rain or snow, and they must bear the name of the authorized person placing the tag on the equipment. If possible, tags should be fastened to the same point as the lock. If not possible, the tag must be near the lock and immediately obvious.

Locks serve as barriers to keep equipment from starting up and causing harm to someone who may be working on that piece of machinery. They must hold the energy isolating devices in a “safe” or “off” position. Locks should be inspected to ensure they are standardized and durable.

Each lock must be keyed differently so no more than one person’s key will open it. If a combination lock is used, only the person placing the lock must know the combination to open it. Locks and tags are placed on equipment for a reason, and should never be ignored or removed by anyone other than the individual who placed them.

When it is not possible to lock a de-energized energy source, only a tag may be used. Tags without locks should be treated as if they were locks. The identity of the person who placed the tag must be described on the tag. This usually includes the person’s name and contact information, such as a phone number.

Lock and Tag Training

OSHA requires that employers train workers so they understand the purpose and function of an energy control program and its lockout and tagout procedures.

Authorized employees are those who receive training in recognition of applicable hazardous energy sources, type and magnitude of the energy available, and methods and means for energy isolation and control. They must receive annual training in the control of hazardous energy, and must be retrained when there is a change in job assignments, machines, or energy control procedures.

Authorized employees are the only employees allowed to apply locks or tags and perform work on isolated equipment.  Prior to starting work, the authorized employee must verify that the equipment is isolated and de-energized. Additionally, they are required to perform annual inspections to ensure energy control procedures are being followed. If deviations in equipment or inadequacies in the use and knowledge of energy control procedures are identified, they must be corrected immediately through repairs, new equipment purchases, or employee retraining.

An affected employee is someone who, during normal operations, uses a machine or equipment on which servicing or maintenance will be performed under a lockout/tagout action, or works in an area in which such servicing or maintenance is being performed.

All others include anyone whose work operations require them to access but not operate machinery in an area where energy control procedures may be utilized. “Others” may include other employees, visitors, or contractors who are working in the area.

Lock and tag procedures are vital to the health and safety of workers.  Employers should be sure to follow OSHA’s standard for the Control of Hazardous Energy to protect their employees from harm.

Let’s run through three basic rules related to the lockout/tagout standard:

  1. Employees should never attempt to remove a lock or tag, or operate a piece of equipment that is locked or tagged.
  2. Locks used for isolating energy sources are required to be dedicated, marked, and not used for any other purpose.
  3. Tags associated with lockout/tagout activities are red, to communicate ‘danger’. They may have different warnings printed on them, such as ‘Do Not Operate’, ‘Do Not Start’, ‘Do Not Open’, ‘Do Not Close’, or ‘Do Not Energize’. Both locks and tags must be constructed to withstand the environment in which they are used.

Worker Responsibility Regarding Locks and Tags

  • Always be aware of and follow lockout/tagout procedures.
  • Never remove a lock or tag.
  • Never attempt to restart, or restore energy to, a machine, circuit, or any equipment that is locked or tagged.
  • Never attempt to bypass equipment that is locked or tagged.

Lockout/tagout training is crucial to the safety of employees working with electrical equipment. Before performing lockout/tagout procedures, ensure that machines and equipment are stopped, isolated from all potentially hazardous energy sources, and locked out before employees perform any servicing or maintenance.

Workers may perform some routine tasks and maintenance without invoking lock and tag procedures. For exceptions to occur, employers must first confirm that tasks for exception are routine, repetitive, and integral to normal production, document excepted tasks in the company’s lock and tag policy, and train workers on ways to conduct tasks safely.

Course Outline
  • Introduction
  • What Is Lock and Tag?
  • What Are the Hazards and Consequences?
  • How Are the Hazards Controlled?
  • OSH Act Section 5(a)(1), known as the General Duty Clause
  • 29CFR 1910.147 - The control of hazardous energy (lockout/tagout or LOTO)
  • Appendix A to 1910.147 – Typical minimal lockout procedure
  • 29 CFR 1910.335 – Safeguards for personnel protection (electrical systems)
  • 29 CFR 1910.145 – Specifications for accident prevention signs and tags
  • ANSI/ASSE Z244.1-2016 - Control of Hazardous Energy Lockout, Tagout and Alternative Methods