What is Lockout Tagout?

Industrial processes evolve over time. This leads to more advanced machines, and these machines require intricate maintenance procedures. Unfortunately, one of today’s main contributors to workplace injuries and fatalities is precisely the servicing that these highly energized systems require.

Such machinery doesn’t have to be in operation to be hazardous. As long as the energy sources like compressed air, steam, natural gas, pressurized water, or electricity are attached to a particular machine, servicing it is risky.

Workers who do repair or maintenance need to know about these hazards. The machines need to be “locked” and “tagged”. And that is precisely why the Lockout/Tagout procedure exists.

How exactly does this procedure work? Why is it so important? Who is responsible for it? In the following paragraphs, we’ll analyze every aspect of this crucial safety policy.

What Exactly is Lockout Tagout?

To put it simply, the Lockout procedure is when the energy is isolated from a particular machine or equipment. This is done physically – an energy-isolating device locks the machine in a safe mode.

These devices typically come with tabs or loops, allowing an individual to lock a stationary machine in a safe position. Usually, it’s a manually-operated line valve, circuit breaker, block, or a disconnect switch.

Tagout procedure, on the other hand, is a simple labeling process. It involves using information indicators or tags with info such as:

  • The name of the individual conducting the Lockout Tagout procedure
  • Why is the procedure needed (maintenance, repair, etc.)
  • Time of application of the procedure

Why is Lock out Tag out so Important?

Every facility is required to have an energy control program in place. Lockout Tagout is one such program. Its primary purpose is to protect employees who are at risk of injuries or death caused by uncontrolled energy.

Here’s an example. Even though they could probably do their job while sleeping, experienced airline pilots still have to go through intricate checklists before every single flight. In a similar fashion, a detailed Lockout/Tagout program makes sure that nobody gets hurt before working on the machinery.

That’s precisely why OSHA requires facilities to have this program in place. Having such a complex procedure may seem like overkill, but it actually makes a lot of sense.

Keep in mind that facilities can have all sorts of machines, each of which can have different safety practices. Similarly, some employees may be more familiar with operating these machines than others.

Without the use of an adequate Lockout/Tagout procedure, a machine could suddenly release a form of energy. This can be electrical, thermal, hydraulic, chemical, pneumatic, or mechanical energy. Any of these forms of energy can cause severe injuries, or even kill.

Consider the following examples of injuries caused by the lack of a Lockout/Tagout procedure:

  • An employee is servicing some equipment or a machine. Inside the equipment, internal wiring shorts and electrocutes the worker.
  • An employee decides to clear the jam on a jammed conveyor. The machine is suddenly freed and crushes the employee.
  • Employees are repairing a piping connection. Another employee opens a valve somewhere along the line. The workers who are repairing the piping get into contact with the fluid and get severe burns.
  • An employee is servicing a press. His colleague doesn’t see him and starts the press. The first employee’s limbs are caught in the press and end up amputated.

These examples showcase how hazardous workplace accidents can be. And that’s precisely why Lockout/Tagout is so important. By making these types of dangerous energies controlled, it stops them from causing harm.

To summarize, a Lockout/Tagout program

  • Prevents contact with hazards during maintenance or any tasks where the safeguarding devices have to be removed
  • Prevents accidental start of equipment or machinery
  • Prevents accidental release of dangerous stored energy
  • Saves lives by preventing approximately 120 fatalities, 50,000 injuries, and 250,000 incidents on an annual basis
  • By reducing equipment downtime, it improves overall productivity
  • Cuts costs by decreasing insurance costs and lost employee time

Why do Lockout/Tagout Violations Happen?

Just like with many different OSHA standards, violations of this procedure are often caused by poor documentation. Employers are required to provide detailed strategies of use for all equipment. Some companies don’t document certain machines, while some don’t have any written procedures at all.

Another common cause is inadequate employee training. Training is not something that only those who operate the machines should undergo. All individuals who work around hazardous machinery need to complete the basic Lockout/Tagout training.

Some workers breach the rules by failing to recognize the sources of hazardous energy. Others violate the standard by simply using the wrong Lockout/Tagout devices.

Some of them are unable to recognize the right devices as they’re not performing regular audits. OSHA requires companies using hazardous equipment to regularly test such equipment. Moreover, Lockout/Tagout procedures need to be regularly evaluated.

Finally, violations often take place because organizations fail to conduct this procedure in the correct order. In the next part of the article, we’ll be taking a look at the elementary steps of locking and tagging dangerous equipment.

How is Lockout Tagout Performed?

This process involves much more than just locking a machine’s switch. It’s a detailed, step-by-step procedure that requires training, coordination, and communication. These are the steps of a Lockout/Tagout program:

  1. Notifying the Employees

The authorized person needs to notify the employees what is going to be locked/tagged and why. He or she also needs to state who is responsible for the procedure, as well as to say who should be contacted for more information.

  1. Equipment Shutdown

When shutting down a machine, the authorized person needs to ensure that all of the machine’s moving parts have stopped completely. These include parts such as spindles, gears, and flywheels. Use the manufacturer’s instructions to do this properly.

  1. Isolation from Hazardous Energy

The next step involves isolating a particular machine from hazardous energy. The exact way in which this can be done this depends on the type of energy:

Electrical Energy – Firstly, put the electrical disconnects to the “off” position. You’ll need to make sure that the breaker connections are in the same position. Finally, lock the disconnects.

Pneumatic & Hydraulic Energy – Close down the valves and lock them into place. To bleed off the energy, use the pressure-relief valves. After that, close the airlines.

Chemical Energy – Close and lockout the valves present on the lines that connect the system with the chemical supply. Bleed the lines in order to remove the chemicals from the appliance.

Gravitational Energy – To prevent parts of the system from moving or falling, use safety blocks or pins.

Mechanical Energy – Slowly release the energy from the compressed springs. If this can’t be done, ensure that all movable parts are blocked.

  1. Removal of Stored or Residual Energy

All stored energy (like the electricity present in batteries or capacitors) has to be restrained, disconnected, or discharged. The authorized person needs to confirm that the reaccumulation of stored energy is not possible.

  1. Lockout

Once the machine is isolated from the energy source and the residual energy is completely removed, it’s time to lock it down. During this step, it is necessary to attach the locking device to the machine’s energy-isolating device. The lockout device should be put into the “safe” position.

A system needs to have as many locks as there are employees who operate it. For instance, if a particular maintenance job requires 3 employees, then there should be 3 locks. These locks should be removable only by those who have placed them.

  1. Tagout

The Tagout part of this procedure involves the use of special tags. Their purpose is to inform the workers about several things – who locked the machine, why he did it, and when he did it. These usually come in the form of symbols or signs.

  1. Verifying the Isolation

Before starting to work on the machine, the authorized person needs to make sure that it is adequately locked out. This can be done in several ways:

  • By engaging the machine’s controls and observing the results
  • By testing the equipment’s circuitry or temperature/pressure gauges, and
  • By the means of visual inspection of its suspended parts, electrical connections, valves, as well as the locking devices.

Once the Lockout/Tagout procedure is complete, service activity can begin.

Who is Responsible for Lock out Tag out?

All parties of a particular company have some responsibility in the Lockout/Tagout program.

Authorized individuals are responsible for:

  • Following the developed procedures
  • Reporting the issues related with the same procedures

Supervisors are responsible for:

  • Ensuring that the workers follow the required procedures
  • Ensuring that only qualified employees conduct maintenance or service requiring a Lockout
  • Ensuring the establishment of equipment-specific strategies for the equipment and machines
  • Distributing protective hardware and ensuring that the workers are using it

Management is responsible for:

  • Measuring and monitoring conformance with the program
  • Providing all necessary appliances, hardware, and protective equipment
  • Identifying the processes, equipment, machines, and workers included in the program
  • Drafting, reviewing, and updating the procedures


While it may seem like an unnecessary, overly-complicated procedure, Lockout/Tagout is vital to everyone’s safety within the facility. Failure to comply with it results in fines, injuries, and potentially even fatalities.

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