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Control of Hazardous Energy (Lockout/Tagout)

UTK Environmental Health & Safety Program GS-080

The purpose of this program is to ensure that the hazardous energy will not be accidentally released during maintenance activities.

Effective Date: 04/22/1998
Revision Date: 05/05/2022

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Environmental Health & Safety has established this program to protect the campus community from the accidental release of hazardous energy. The Occupational Safety and Health Administration’s (OSHA) Control of Hazardous Energy (also known as lockout/tagout) is the basis of this program.

Scope and Applicability

These guidelines cover the servicing and maintenance of machines and equipment in which the unexpected energization or start-up of the machines or equipment or release of stored energy could cause injury to employees, students, or visitors. This standard establishes minimum performance requirements for the control of such hazardous energy.

This standard does not cover the following:

  • Construction and agriculture employment
  • Employment is covered by parts 1915, 1917, and 1918 of this title.
  • Installations under the exclusive control of electric utilities for the purpose of power generation, transmission, and distribution, including related equipment for communication and metering.
  • Exposure to electrical hazards from work on, near, or with conductors or equipment in electric-utilization installations, which is covered by subpart S of this part and
  • Oil and gas well drilling and servicing.

This standard applies to the control of energy during servicing and/or maintenance of machines and equipment.

Abbreviations and Definitions


Affected employee: An employee whose job requires him/her to operate or use a machine or equipment on which servicing or maintenance is being performed under lockout or tagout or whose job requires him/her to work in an area in which such servicing or maintenance is being performed.

Authorized employee: A person who locks out or tags out machines or equipment to do service or maintenance work. An affected employee becomes an authorized employee when that employee’s duties include service or maintenance work on equipment.

Capable of being locked out: An energy-isolating device that is designed with a hasp or other means of attachment to which, or through which a lock can be affixed, or if it has a locking mechanism built into it. Other energy-isolating devices will also be considered to be capable of being locked out if lockout can be achieved without the need to dismantle, rebuild, or replace the energy-isolating device or permanently alter its energy control capability.

Disconnect: A switch that disconnects an electrical circuit or load (motor, transformer, or panel) from the conductors that supply power to it. An open circuit does not allow electrical current to flow. Under a lockout procedure, a disconnect must be capable of being locked in the open position.

Energized: Connected to an energy source or containing potential energy.

Energy source: Any source of energy. Examples: electrical, mechanical, hydraulic, pneumatic, chemical, and thermal.

Energy-isolating device (EID): A mechanical device that physically prevents transmission or release of energy, including but not limited to the following: a manually operated electrical circuit breaker, a disconnect switch, a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply connectors, and, in addition, no pole can be operated independently; a line valve, a block, and any similar device used to block or isolate energy. Push buttons, selector switches, and other control circuit type devices are not energy isolating devices.

Hazardous energy: Any of the types of energy existing at a level or quantity that could be harmful to workers or cause injury through inadvertent release or start-up of equipment.

Hot Tap: A procedure used in the repair, maintenance, and services activities which involves welding on a piece of equipment (pipelines, vessels, or tanks) under pressure in order to install connections appurtenances. It is commonly used to replace or add sections of a pipeline without the interruption of service for air, gas, water, steam, and petrochemical distribution systems.

Lockout: Placing a lockout device on an energy-isolating device under an established procedure to ensure the energy-isolating device and the equipment it controls can’t be operated until the lockout device is removed. (An energy-isolating device is capable of being locked out if it has a hasp that accepts a lock or if it has a locking mechanism built into it.)

Lockout device: a device that utilizes a positive means, such as a lock, either key or combination type, to hold an energy-isolating device in a safe position and prevent the energizing of a machine or equipment. Included are blank flanges and bolted slip binds.

Normal production operations: The utilization of a machine or equipment to perform its intended production function.

Procedure: A series of steps taken to isolate energy and shut down equipment.

Setting up: Any work performed to prepare a machine or equipment to perform its normal production operation.

Servicing or maintenance: Workplace activities such as constructing, installing, setting up, adjusting, inspecting, modifying, and maintaining machines or equipment. Also includes lubricating, cleaning, unjamming, and making adjustments or tool changes if a worker may be exposed to the unexpected start-up of the equipment during such activities.

Tagout: The placement of a tagout device on an energy-isolating device, in accordance with an established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed.

Tagout device: A prominent warning device, such as a tag and a means of attachment, which can be securely fastened to an energy-isolating device in accordance with an established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed.

Roles and Responsibilities

EHS shall:

  • Serve as a technical resource for questions and comments for the lockout/tagout program and periodically review compliance with this program.
  • Post the most recent edition of this document on the EHS website.
  • Review and revise this document periodically and upon notice of the need for changes.
  • Maintain records as required.
  • Provide general training on lockout/tagout safety upon request.

Supervisors shall:

  • Enforce the use of lockout and tagout devices when employees do service or maintenance work and may be exposed to hazardous energy
  • Notify affected employees of lockout/tag-out procedures that are going to take place in their work area.
  • Develop and maintain safe shut down procedures on each piece of equipment or machine that their employees are expected to service or maintain.
  • Ensure that employees are properly trained on the use of lockout/tagout devices.
  • Maintain written procedures developed for equipment containing more than one energy source.
  • Maintain training and audit records.
  • Ensure employees have the proper lockout tagout equipment.
  • Ensure that specific policies and procedures concerning lockout/tagout safety practices are in place.
  • Ensure authorized individuals are inspected annually on lockout/tagout.

Authorized Individuals shall:

  • Follow the lockout/tagout procedures described in this document.
  • Notify their supervisor when they have any questions about isolating energy sources safely; have observed on-compliance activities or when problems are identified with equipment or lockout devices.
  • Comply with the UT lockout/tagout procedures and the specific shut down procedures
  • Perform audits on lockout tagout but do not use lockout/tagout on the equipment that is being audited.
  • Participate in training on the purpose and use of energy control procedures.

Affected Employees (non-authorized employees) shall:

  • Participate in awareness training concerning the procedures and the prohibition against starting machines that are locked or tagged out.

Contractors and Subcontractors shall:

  • Comply with all provisions of UT’s Lockout/Tagout procedures.
  • Ensure that his or her employees are appropriately trained and authorized.
  • Comply with any shutdown procedures that have been developed by the University for each Machine or piece of equipment that the contractor must service or maintain or other such projects where energy sources are present. When shut down procedures are not available from the University, the contractor shall develop and provide the University with their own shutdown procedures for that machine or piece of equipment or project.


Energy Control Procedure (29 CFR 1910.147 (C) (4) (ii)

A specific procedure must be developed for equipment containing more than one energy source. A copy of the procedure should be kept in the department’s file, and ideally, a copy posted at the equipment.

The Lockout/Tagout Procedure (Appendix A) provides a good template for procedure development. Environmental Health and Safety is available to assist in the development of written procedures.

Procedures shall clearly outline the scope, purpose, authorization, rules, and techniques to be used. If an error or omission is detected in a specific written procedure, it is the responsibility of the authorized individual who identifies the error or omission to bring it to the attention of his or her supervisor. Corrections must then be made and communicated to each authorized individual who works with this procedure.

The procedure must include the following:

  1. A specific statement of the intended use of the procedure.
  2. Specific procedural steps for shutting down, isolating, blocking, and securing machines or equipment to control hazardous energy.
  3. Specific procedural steps for the placement, removal, and transfer of lockout devices or tagout devices and the responsibility for them and
  4. Specific requirements for testing a machine or equipment to determine and verify the effectiveness of lockout devices, tagout devices, and other energy control measures.

The employer does not need to document the required procedure for a particular machine or equipment, which all of the following elements exist:

  1. The machine or equipment has no potential for stored or residual energy or re-accumulation of stored energy after shut down, which could endanger employees
  2. The machine or equipment has a single energy source that can be readily identified and isolated.
  3. The isolation and locking out of that energy source will completely de-energize and deactivate the machine or equipment.
  4. The machine or equipment is isolated from that energy source and locked out during servicing or maintenance.
  5. A single lockout device will achieve a locked-out condition.
  6. The lockout device is under the exclusive control of the authorized employee performing the service or maintenance.
  7. The servicing or maintenance does not create hazards for other employees.
  8. The employer, in utilizing this exception, has had no accidents involving the unexpected activation or re-energization of the machine or equipment during servicing or maintenance.

Hot Tap Work

Hot taps involve working on equipment while it is energized. Hot tap work is discouraged and should only be done where it is infeasible to do otherwise and must be done by knowledgeable authorized individuals.

Where hot tap work is conducted, additional precautions must be taken, and specific written procedures must be developed. Authorized individuals performing hot tap work must be trained in these procedures.

Signs and Warnings

Signs must be placed on all equipment requiring lockout/tagout at the energy isolation device.

Lockout and tagout devices:

Lockout and tagout devices must meet the following criteria to ensure that they are effective and not removed inadvertently:

  • Lockout devices must work under the environmental conditions in which they are Locks shall only be used for lockout purposes and shall be “heavy-duty.” Heavy-duty is defined as a lock that can be removed only with heavy-duty bolt cutters
  • Tagout device warnings must remain legible even when they are used in wet, damp, or corrosive conditi Tags shall be held in place with a tie capable of withstanding 50 lbs. of force. At least one tag must be provided for locations where locks are applied. Note that if more than one energy isolation device (EID) is locked out, there must be a tag at each EID.
  • Lockout and tagout devices must be designated by color, shape, or siz The locks and tags used for lockout shall be standardized within each department. An authorized individual should never lend their lock or key to anyone else. Tagout devices must have a standardized print and warning format.
  • 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 ti
  • Any employee who sees a lockout or tagout device must be able to recognize who attached it and its purp
  • Each lock must have a unique key or combinati An authorized individual should never lend their lock or key to anyone else. There may be situations where several locks are necessary for a lockout. A department may elect to have several locks that can be used as a unit. However, control must be maintained over the keys.
  • Energy-isolating devices are the primary means for protecting UT employees who service equipment and must be designed to accept a lockout devi Energy isolating devices must clearly identify their function.

Electrical energy sources

Lockout or tagout of electrical energy sources must occur at the circuit disconnect switch. Electrical control circuitry does not effectively isolate hazardous energy. See also, Alternative methods.

Lock Removal

Locks and/or tags must not be removed by anyone other than the authorized individual who installed it. There is one exception to this rule. The authorized individual’s supervisor may remove his or her lock, but only when it is absolutely necessary to remove the lockout/tagout. If the lock and/or tag are removed, every effort must be made to notify the authorized individual that his or her lock has been removed. Efforts to be made to notify the authorized individual that their lock has been removed include:

  • Verification that the authorized employee who applied the device is not on-site;
  • Make all reasonable efforts to contact the authorized employee to inform him/her that his/her lockout or tagout device has been removed; and
  • Ensuring that the authorized employee has this knowledge before he/she resumes work on the site.

Equipment for lockout/tagout

The following is a list of equipment that may be used in a lockout. An adequate supply of each required item must be available for the authorized individual.

  1. Lock and key
  2. Tags and ties
  3. Multiple lock hasp
  4. Lockbox (if used in the department)
  5. Breaker locks
  6. Fuse pullers
  7. Insulated mats
  8. Hot sticks
  9. Chains
  10. Electrical meter to determine the status of an electric circuit
  11. Valve covers
  12. Blocks
  13. Blanks
  14. Jacks
  15. Supports (posts, columns, timbers, etc.)
  16. Other items as necessary

Lockout/Tagout Inspection (29 CFR 1910.147 (c )(6)):

The OSHA standard requires that the employer shall conduct a periodic inspection of the energy control procedure at least annually to ensure that the procedure and the requirements of this standard are being followed. The audit must be conducted by an authorized individual who is authorized to perform a lockout/tagout but does not use lockout/tagout on the equipment that is being audited. To assist departments in auditing, an audit checklist has been developed (see Appendix B).

This form, or a similar record, should be maintained in the department’s files.

Off-Site Safety:

Each department head is responsible for identifying lockout/tagout activities affecting their employees and students while engaged in University-sponsored activities away from the main campus. Provisions shall be made to assure that these individuals are not exposed to hazards posed by activities requiring lockout/tagout.

Exposure survey:

Authorized Individuals will conduct a hazardous-energy survey to determine affected machines and equipment, types and magnitude of energy, and necessary service and maintenance tasks. Each task will be evaluated to determine if it must be accomplished with lockout or tagout procedures.

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

  1. Inform all affected employees of the equipment shutdown.
  2. Shut down equipment.
  3. Isolate or block hazardous energy.
  4. Remove any potential (stored) energy.
  5. Lockout or tagout the energy sources.
  6. Verify the equipment is isolated from hazardous energy and de-energized.

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

  1. Remove tools and replace machine or equipment components.
  2. Inform coworkers about energy-control device removal.
  3. Ensure all workers are clear of the work area.
  4. Verify machine or equipment power controls are off or in a neutral position.
  5. Remove the lockout or tagout device.
  6. Re-energize equipment.

Specific energy-control procedures

Departments have developed specific energy-isolation procedures for all machines and equipment that have energy-isolating devices

Special lockout/tagout situations

Energized testing: When an energy-isolating device is locked or tagged, and it is necessary to test or position equipment, do the following:

  1. Remove unnecessary tools and materials.
  2. Ensure that all other employees are out of the area.
  3. Remove locks or tags from energy isolating devices.
  4. Proceed with the test.
  5. De-energize equipment and lockout or tagout energy-isolating devices.
  6. Operate equipment controls to verify that the equipment is de-energized.

Contract service and maintenance

The OSHA standard requires that contractors be made aware of specific lockout/tagout procedures. Note this applies to “specific” procedures and not the general procedure found in Appendix A. Both UT employees and contractors must be aware of their respective lockout/tagout procedures before the contractor does on-site work. UT employees must understand and comply with the contractor’s energy-control procedures.

Group lockout

When authorized employees must service equipment that has several energy sources and several energy-isolating devices, the employees must follow specific group lockout procedures.

Shift changes and long-term shutdowns

Employees must follow the department’s specific written procedures when it is necessary to continue lockout/tagout when work shifts change and during long-term shutdowns. Supervisors are responsible for monitoring lockout and tagout devices that control the energy to equipment during long-term shutdowns

Alternative methods

  • When lockout or tagout is not used for tasks that are routine, repetitive, and integral to the production process, or prohibits the completion of those tasks, then an alternative method must be used to control hazardous energy.
  • Selection of an alternative control method must be based on a risk assessment of the machine, equipment, or process. The risk assessment must consider existing safeguards provided with the machine, equipment, or process that may need to be removed or modified to perform a given task. For example, when control circuits are used as part of the safeguarding system, the system must be designed to ensure protection as effective as a mechanical disconnect switch or master shut-off valve. A control-reliable dual-channel hardwired circuit of industrially-rated components that satisfies the design features as specified in ANSI B11.19, with a safety relay or safety PLC to ensure integrity and performance of the safeguarding system, must be used.
  • Under all circumstances, the individual must have exclusive personal control over the means to maintain the state of the control circuit in a protective mode.

Inspections of written energy-control procedures

Lockout/Tagout Auditing (29 CFR 1910.147 (c)(6)):

The OSHA standard requires that the employer shall conduct a periodic inspection of the energy control procedure at least annually to ensure that the procedure and the requirements of this standard are being followed. The audit must be conducted by an authorized individual who is authorized to perform a lockout/tagout but does not use lockout/tagout on the equipment that is being audited. To assist departments in auditing, an audit checklist has been developed (see Appendix B).

This form, or a similar record, should be maintained in the department’s files.

Authorized Employees or Supervisors will perform and document annual inspections of energy-control procedures to ensure that employees understand and use them effectively. Documentation will include the following:

  • The equipment on which the procedure is used.
  • The date of the inspection.
  • The employees included in the inspection.
  • The inspector.

If an inspector finds that employees are not following an energy-control procedure or that the procedure is not protecting them, employees must be retrained and the procedure’s deficiencies corrected. The inspector must understand the procedure and must be someone other than those following the procedure at the time of the inspection. Each procedure’s accuracy, completeness, and effectiveness must be verified.

If the inspection covers a procedure for equipment with an energy-isolating device that can be locked out, the inspector must review the procedure with the employees who use it to service the equipment. The inspector can review the procedure with the employees individually or in a group.

If the inspection covers a procedure for equipment with an energy-isolating device that can only be tagged out, the inspector must review the procedure with the authorized employees who service the equipment and with affected employees who may work in the area when the equipment is serviced. The inspector can review the procedure with the employees individually or in a group. See Appendix B for a sample Annual Employee Audit form.

Training (29 CFR 1910.147 (C) (7)

Employees who may be exposed to hazardous energy will receive training before assignment to ensure that they understand UT’s energy-control procedures and the department-specific procedures and have skills to apply, use, and remove energy controls. The training will include the requirements of 1910.147 and the following:

  • Affected employees will be trained in the purpose and use of energy control procedures. An affected employee uses equipment that is being serviced under lockout or tagout procedures or works in an area where equipment is being serviced.
  • Authorized employees will be trained to recognize hazardous energy sources, the type and magnitude of energy in the workplace, the methods and means necessary for isolating and controlling energy, and the means to verify that the energy is controlled. An authorized employee locks out or tags out equipment to do service work. An affected employee becomes an authorized employee when that employee’s duties include service or maintenance work on equipment.
  • Employees whose jobs are in areas where energy-control procedures are used will be trained about the procedures and the prohibition against starting machines that are locked or tagged out.
  • Employees will be retrained annually to ensure they understand energy-control procedures.
  • Authorized and affected employees will be retrained whenever their job assignments change, energy-control procedures change, equipment or work processes present new hazards, or when they don’t follow energy-control procedures.

Current training records will be maintained for each authorized and affected employee, including the employee’s name and the training date. A sample form documenting training certification is found in Appendix C. Authorized individuals shall be trained in lockout/tagout procedures. Training shall be provided to the following individuals:

  • New employees;
  • Employees who have transferred into the department;
  • Employees who demonstrate a lack of knowledge in the lockout/tagout procedure;
  • When new equipment is introduced, or when a specific procedure is developed or modified; and
  • Periodic refresher – recommended annually.

Sources of Training:

  1. Programs (traditional classroom) are available upon request by Environmental Health & Safety.
  2. SkillSoft provided via K@TE
  3. Certification – A multiple-question test. Successful completion of this test (minimum score of 70%) documents the level of knowledge of the employee.
  4. Other approved sources.

The above-listed sources of training are generic in nature and provide an excellent base for knowledge for the authorized individual. However, complex equipment with more than one source of energy requires a specific written procedure. Individuals performing work on complex equipment should be trained on the procedures for that equipment.


Training must be documented. Each department must maintain a record of the training. The following information should be contained in the training record: date of training, instructor, name of the employee, location, and a brief description or outline of what was covered.

Provisions shall be made for individuals who have limited reading skills to ensure they are familiar with the necessary information.

A test is suggested at the end of each training program to demonstrate that the participants have the requisite knowledge.


OSHA 29 CFR 1910.147

SA0100 – Safety and Environmental Health Program


The information provided in these guidelines is designed for educational use only and is not a substitute for specific training or experience.

The University of Tennessee Knoxville and the authors of these guidelines assume no liability for any individual’s use of or reliance upon any material contained or referenced herein. The material contained in these guidelines may not be the most current.

This material may be freely distributed for nonprofit educational use. However, if included in publications, written or electronic, attributions must be made to the author. Commercial use of this material is prohibited without express written permission from the author.


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