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To prevent injuries and fatalities from unexpected and/or accidental release of energy or start up of machines or equipment, or release of stored energy during service, repair, maintenance, operation, and associated activities; and to outline general procedures for the safe lockout and tagout of electrical equipment, machinery and pressure systems.

Who Performs / Responsible:

  • Health & Safety Co-Chairs
This procedure is reviewed and approved by the Joint Health & Safety Committee. Any employee or contractor who performs a procedure related to this procedure is responsible for following its direction.


You must obtain the following approval(s) prior to starting the task:

Director, Campus Operations OR Manager, Campus Facilities OR Designated authorized employee.

Terms and Definitions:



Affected employee
An employee who operates or uses a machine or equipment on which employee lockout/tagout systems are installed, or who works in areas affected by lockout/tagout procedures.
Authorized employee
A person who locks out and tags out machines or equipment to perform servicing or maintenance. An authorized employee is also someone who has received lockout/tagout training.
Energy source
Any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, gravitational, stored or other energy.
Hot Tap
A procedure used in repair and maintenance activities which involves welding on a piece of equipment (pipelines, vessels or tanks) under pressure, in order to install connections or appurtenances. It is commonly used to replace or add sections of pipeline without the interruption of service for air, gas, water and steam distribution systems. Other methods of attachment can also be used.
A process to ensure that a machine is removed from service and completely protected from inadvertent start-up via any power source. A mechanical device is used (a disconnect switch, line valve, block, blank off plate) that physically prevents the transmission or release of an energy source to machinery or equipment.
To physically neutralize all energy sources in machinery or equipment, usually by applying locks, before beginning any maintenance or repair work. The primary purpose of lockout is to prevent all energy isolation devices (switch, circuit breaker or valve) from accidentally or inadvertently being operated while workers are working on equipment.
Lockout Device
A device that uses a positive means (such as a lock) to hold an energy isolation device (see “Isolation”) in a safe position and prevent the energizing of a machine or a piece of equipment. Each lockout device must always be accompanied by a tagout device. All lockout devices, must:
- be unique, distinctive, easily recognizable, and clearly visible
- be the only devices used for controlling potentially hazardous energy
- not be used for any other purpose
- be capable of withstanding the environment to which they are exposed
- be substantial enough to prevent operation of the energy isolating device without
the use of excessive force

Locks, by themselves, do not de-energize equipment. They are attached only after the machinery has been isolated from its energy sources.
Maintenance and repair
Workplace activities such as constructing, installing, setting up, adjusting, inspecting, modifying, and maintaining machines or equipment. These activities include but are not limited to lubrication, cleaning or un-jamming of machines or equipment and making adjustments or tool changes, where the employee may be exposed to the unexpected start-up of the equipment or release of hazardous energy.
Tagout device
A tag or sign, which must be attached to the lockout device, which is used to communicate vital information about the lockout, including the identity of the authorized employee who applied the device, the reason for locking out, and the date and time. It also warns workers not to operate that equipment. The tag must be substantial enough to withstand the environment, be secured to prevent inadvertent or accidental removal, and it must remain legible for the duration of the job. It must be made of non-conducting material and be placed in a conspicuous location.
Zero energy state
The mechanical potential energy in all elements of a machine is dissipated so that operation of any control will not produce a movement that could cause injury.

Responsible Department or Functional Area:

  • Campus Operations
  • Joint Health & Safety Committee


  • Campus Operations
  • Information Technology
  • Joint Health & Safety Committee


Access the following before starting this procedure:

  • Appropriate Lockout Device for the Equipment being accessed


Performing this procedure improperly could result in:

  • serious injury or death.
General Lockout Procedure 

How / What to Do:

(1) Preparation for shutdown - the supervisor or authorized employee shall:
  • Identify the types and magnitude of energy to be controlled
  • Identify all hazards (including stored energy)
  • Identify the method or means of controlling the energy
  • Identify the location of switches, energy sources, controls, interlocks or other such devices necessary to isolate the system.
  • Assess the consequences of shutdown
  • Notify all affected persons that the equipment will be shutdown and
    locked/tagged out

Who Performs this Step:

Supervisor or authorized employee.
Equipment shutdown 

How / What to Do:

The equipment will be shutdown following established procedures; ensure that all points of operation are considered, including remote control points.
Equipment isolation 

How / What to Do:

The equipment shall be isolated by following established isolation procedures which specify the use of disconnect switches, line valves, blocks, blanks, etc., as required.
Application of lockout devices 

How / What to Do:

Locks shall be applied to each of the isolation devices. Each employee working on the equipment is responsible for attaching his/her personal lock and keeping the key, without exception. Tags must be attached to each lockout device and should state the name, the reason for locking out, the date and time.
Release of stored energy (de-energization) 

How / What to Do:

All potentially hazardous stored or residual energy must be relieved, blocked, bled, restrained, grounded or rendered safe by authorized employees. Additional measures may be necessary to prevent the re- accumulation of energy. Each worker must ensure that this has been done.
*See attachments for specific Lockout Guidelines and continue reading*
Verification of isolation  

How / What to Do:

Prior to starting the work, and after isolation and de- energization, the authorized employee should perform a test of all start buttons and other activating controls on the equipment, check potential of the electrical supplies to ensure the equipment has been de-energized. Return all of the controls to the off or neutral position after trying to start. Note: Each person who has placed a personal lock on the equipment should be assured of his/her right to verify individually that the potentially hazardous energy has been isolated and/or de-energized before the repair or maintenance work begins.

Who Performs this Step:

Authorized Employee
Release from lockout control 

How / What to Do:

Prior to restoring energy to the equipment, the authorized employee will perform an assessment of the work area to determine that:
  • the machine or equipment is operationally intact
  • all necessary guards have been re-installed
  • all tools and materials used during the repair or maintenance work have been removed
  • all temporary de-energization measures and devices have been removed by those who placed them
  • all other workers and affected individuals have been informed that the energy is about to be restored and are clear of the equipment

    The last lock to be removed should be that of the person supervising the lockout. This responsibility should not be delegated to another person. Follow the required steps to re- energize the system.

Emergency Contact:

In case of an emergency, please contact:

In the case of serious injury, death, fire or other incident, contact 911 immediately.
Contact reception (dial 0) to contact security and Director, Campus Operations

Primary Author / Owner:



Health & Safety Co-Chairs [email protected]