Lock Out/Tag Out (LOTO)

Lockout/ Tagout refers to specific practices and procedures to safeguard employees from the unexpected energization or startup of machinery and equipment, or the release of hazardous energy during service or maintenance activities. This requires, in part, that a designated individual turns off and disconnects the machinery or equipment from its energy source(s) before performing service or maintenance and that the authorized employees either lock or tag the energy-isolating devices to prevent the release of hazardous energy and take steps to verify that the energy has been isolated effectively. If the potential exists for the release of hazardous stored energy or for the re-accumulation of stored energy to a hazardous level, the employer must ensure that the employees take steps to prevent injury that may result from the release of the stored energy.


Lock Out

Locking out is a procedure for securing an energy isolating device in an off, closed, or neutral position. When an energy-isolating device is locked out, a worker can safely service hazardous equipment. A lockout device is typically a lock with a unique key or combination and secures the energy-isolating device in a safe position. When an energy-isolating device is locked out, the equipment it controls will not work until the lockout device is removed.


Tagging out is a procedure for placing a warning tag or sign on an energy-isolating device. Tagout devices control hazardous energy as effectively as lockout devices, but tagout devices don’t provide the same physical barrier to hazardous energy as lockout devices, so they can be removed easily or worn-out with time reducing their actual effectiveness. A tagout device must be securely fastened to the energy-isolating device and must state that the equipment being serviced can’t be operated until it is removed.

Normally lockout and tagout is used in conjunction to each other in industries to control release of hazardous energy and prevent accidents.

Requirements of Lockout Tagout Devices

All lockout & tagout devices used should fulfill these minimum requirements.

  • Durable: Lockout devices must work under the environmental conditions in which they are used. Warnings on tagout devices must be legible even in wet, damp, or corrosive conditions.
  • Standardized: Lockout and tagout devices must be designated by color, shape, or size. Tagout devices must have a standardized print and warning format.
  • Substantial: Lockout devices and tagout devices must be strong enough that they can’t be removed inadvertently. Tagout devices must be attached with a single-use, self-locking material such as a nylon cable tie.
  • Identifiable: Any employee who sees a lockout or tagout device must recognize who attached it and understand its purpose. Each lock must have a unique key or combination; this means that only the employee who uses the lock has the key or the combination to that lock.

Lockout/Tagout Procedure

  • Notify all affected employees that a lockout or tagout system is going to be utilized and the reason therefore. The authorized employee shall know the type and magnitude of energy that the machine or equipment utilizes and shall understand the hazards thereof.
  • If the machine or equipment is operating, shut it down by the normal stopping procedure (depress stop button, open toggle switch, etc.).
  • Operate the switch, valve, or other energy-isolating device(s) so that the equipment is isolated from its energy source(s). Stored energy (such as that in springs, elevated machine members, rotating flywheels, hydraulic systems, and air, gas, steam, water pressure, etc.) must be dissipated or restrained by methods such as repositioning, blocking, bleeding down, etc.
  • Lockout and/or tagout the energy-isolating devices with assigned individual lock(s) and/or tag(s). a. After ensuring that no personnel are exposed, and as a check on having disconnected the energy sources: b. Operate the push button or other normal operating controls to make certain the equipment will not operate.
  • If the equipment may be operated from a remote station or computer control system the authorized employee MUST verify that the equipment will not start remotely. CAUTION: Return operating control(s) to “neutral” or “off” position after the test.
  • The equipment is now locked out and/or tagged out.

Isolation Device

Isolation device is a mechanical device that physically prevents the transmission or release of energy. Examples of isolation devices are disconnect switches, slide gates, double valves, blocks, spectacle blinds and blind flanges.

Energy Control System

The purpose of the energy control system is to ensure that whenever the possibility of unexpected machine or equipment startup or energization exists, or when the unexpected release of stored energy could occur and cause injury during servicing and maintenance, the equipment is isolated from its energy sources, and rendered inoperative prior to servicing or maintenance. Energy Control System should include:

  • A Documented energy control procedures,
  • Employee training program, and
  • Periodic inspections of the use of the procedures

The energy control procedures must include the following steps:

  • Preparing for shutdown
  • Shutting down the machine or equipment
  • Isolating the machine or equipment from the energy sources
  • Applying the lockout or tagout devices to the energy-isolating devices
  • Safely releasing all potentially hazardous stored or residual energy
  • Verifying the isolation of the machine or equipment prior to the start of servicing or maintenance work

Before removing Lockout and Tagout

Before lockout or tagout devices are removed and energy is restored to the machines or equipment, following steps must be taken to reenergize equipment after servicing is completed:

  • Ensuring that machines or equipment components are operationally intact;
  • Ensuring that all employees are safely positioned or removed from equipment;
  • Ensuring that lockout or tagout devices are removed from each energy-isolating device by the employee who applied the device.

Employee’s Responsibilities

Before Maintenance

Employees must do the following, before they begin service or maintenance work:

  • Inform all affected employees of equipment shutdown.
  • Shut down equipment.
  • Isolate or block hazardous energy.
  • Remove any potential or stored energy.
  • Lock out or tag out the energy sources.
  • Verify the equipment is isolated from hazardous energy and de-energized.

Before removing Lockout Tagout Devices

Employees must do the following before they remove lockout or tagout devices and re-energize equipment:

  • Remove tools and replace equipment components.
  • Inform co-workers about energy-control device removal.
  • Ensure all workers are clear of the work area.
  • Verify power controls are off or in a neutral position.
  • Remove the lockout or tagout device.
  • Re-energize equipment.

Awareness Training

All employees must be trained to know basic hazardous-energy concepts and the purpose of the devices used to control hazardous energy. They should also know what tasks might expose them to hazardous energy and how hazardous energy can be controlled. The training should include:

  • The purpose of energy-control procedures.
  • How energy-control procedures are applied.
  • How energy-control procedures will protect them.

Employees, who lock out or tag out equipment and service or maintain the equipment, should be given additional training covering:

  • How to find and recognize hazardous energy sources
  • The types and magnitudes of energy used in the workplace
  • How to isolate energy sources

Inspection and Monitoring

The purpose of the inspection is to determine that employees are following the written lockout tagout procedure and that the procedure is correct. If during inspection, it is observed that employees are not following an energy-control procedure, or that the procedure is not protecting them, those employees must be retrained and the procedure’s deficiencies should be corrected immediately. Regular inspection and monitoring will go a long way in improving safety at workplace, and prevention of accidents and injuries.

Routine Inspections

The supervising department shall continually monitor employee performance with regard to compliance with this program and shall correct any deviations or inadequacies observed.

Periodic Inspections

At least annually, supervising departments shall conduct a periodic inspection. This periodic inspection shall include:

  • A separate review of each written energy control procedure. This will ensure that the procedures are adequate to provide the necessary protection and to identify what changes, if any, are needed.
  • Observing the implementation of an energy control procedures.

Fatal Five

Always keep following fatal five main causes of Lockout Tagout Injuries:

  • Failure to stop equipment before starting maintenance on the equipment, thinking that present maintenance job is very small.
  • Failure to disconnect from power source
  • Failure to dissipate residual energy
  • Accidental restarting of equipment
  • Failure to clear work area before restarting.

Using Tags -Beware

If for energy control of some equipment, you are using tagout only then beware of following points.

  • Tags are only warning devices. Even if they are in place, somebody else can start the equipment.
  • Tags must be securely attached. Tags not securely attached may give away and other person will not be able to know, that you are working on that equipment. If he starts the equipment, you will be in great danger.
  • Tags may evoke false sense of security!
  • Tags do not provide physical restraint! Tags must withstand environmental conditions!
  • Tags must be legible and understandable!

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