Hazardous Energy Control - Lockout/Tagout

Updated June 28, 2022

The UW Hazardous Energy Control Lockout/Tagout (LOTO) Program was developed to prevent personal injury or illness resulting from unexpected start-up, energization or release of stored energy during servicing and maintenance of machines and equipment. The program is in accordance with the requirements in the Washington Administrative Code (WAC) 296-803 and aligns with standards established by the federal Occupational Safety and Health Administration (OSHA).

Hazardous energy, such as electricity, chemical, radiation, pneumatic, hydraulic, mechanical and gravitational energy sources, must be isolated and dissipated before servicing or maintaining equipment. Hazardous energy controls are generally known as Lockout/Tagout, or LOTO, and consist of locks and tags applied to energy-isolating device(s) on equipment that contains the hazardous energy source(s).

The UW Hazardous Energy Control LOTO Program Manual includes:

  • Processes to identify and isolate hazardous energy sources
  • Defines and describes energy-isolating devices on equipment
  • Defines and describes lockout/tagout devices and lock types
  • Hazardous energy control procedures and safe work practices
  • A template for departments to document LOTO procedures specific to their department as a supplement to the UW Hazardous Energy Control LOTO Program Manual
  • Written LOTO procedure types, requirements and forms
  • Specific procedures for certain operations, group LOTO
  • Training requirements
  • Forms to document departmental periodic reviews of LOTO procedures and employees doing LOTO, and annual audits

The UW Hazardous Energy Control LOTO Program applies to all University organizational units at all locations including the Seattle campus, UW Bothell, UW Tacoma, UW Medical Center, Harborview Medical Center, University-owned property University-leased space and temporary field locations under the control of University operations staff.

What you need to know

What you can do to stay safe

Authorized Persons:

  • Always communicate and coordinate LOTO work with Affected Persons, and others as needed.
  • Always follow LOTO procedures when working on applicable equipment.
  • Suggest changes to LOTO procedures that need improvement for safety reasons.
  • Report equipment that does not have LOTO procedures and may pose a hazard.
  • Report all incidents and near misses involving the release of hazardous energy to your supervisor immediately, and to EH&S using the Online Accident Reporting System (OARS).
  • Contact EH&S for advice or information.

Employees, students and visitors, including Affected Persons:

  • Ask questions if unclear about the LOTO program and procedures and how it affects your work area.
  • Know what equipment in the area needs to be maintained and serviced using LOTO procedures.
  • Know who are the Authorized Persons for your area.
  • Never touch or try to start up equipment that has been locked and tagged out, and tell others as needed.
  • Ask about equipment that does not have LOTO procedures and you think may pose a hazard.
  • Understand and follow instructions from Authorized Persons.
  • Report all incidents and near misses involving the release of hazardous energy to your supervisor immediately, and to EH&S using the Online Accident Reporting System (OARS).
  • Contact EH&S for advice or information.

Services available

EH&S provides consultation and assistance to departments/units to comply with the requirements of the LOTO program, and provide or coordinate LOTO training for Authorized Persons.

LOTO equipment resources are available through UW Procurement Services.

Frequently Asked Questions (FAQ)

Injuries depend on the type of hazardous energy and the degree of exposure, but may include lacerations, crushed or fractured body parts, amputations, cuts, burns, electrocution or fatalities.

All hazardous energy control procedures are to be reviewed at least annually by an Authorized Person that is not involved in an active LOTO procedure at the same time as the review. Review infrequently used procedures before use, if not annually.

Tagout devices may be used alone if the employer can demonstrate that its tagout program provides "full employee protection," as required by OSHA Standard 1910.147(c)(3).

Additional safety measures for the tagout ("Tags Plus") are mandated, given the inherent limitations of a tag, in order to achieve a level of safety that is equivalent to that which would be achieved through a lockout system. In other words, you must implement additional safety measures that "bridge the gap" between the degree of safety achieved through lockout and the degree of safety achieved through tagout. An additional safety measure could be removing the fuse in addition to the tagout device, for example.

More information


An employee who is required to operate, use, or be in the area where a machine or equipment could be locked or tagged out for service or maintenance

An employee who locks out or tags out a machine or equipment to do service or maintenance

An energy-isolating device that can be locked in the "off" or "safe" position

A designated Authorized Person responsible for the exclusive control of energy isolating devices installed on an electrical utility system

Isolated from all energy sources and not containing residual stored hazardous energy

Includes University personnel (as defined in Administrative Policy Statement 40.1), faculty, staff, paid student workers, contractors, and vendors

Connected to an energy source, or containing residual or stored energy

A mechanical device that physically prevents transmitting or releasing of energy; this includes, but is not limited to:

  • Manually operated electrical circuit breakers
  • Disconnect switches
  • Manually operated switches that disconnect the conductors of a circuit from all ungrounded supply conductors if no pole of the switch can be operated independently
  • Line valves
  • Blocks
  • Similar devices used to block or isolate energy
  • Similar devices used to block or isolate energy.

Note: Push buttons, selector switches and other control circuit type devices are not energy-isolating devices.

Any source of electrical, mechanical (hydraulic, pneumatic), chemical, thermal or other energy, including gravity

Locks applied to energy-isolating devices during a Group LOTO procedure involving a lockbox; equipment locks may be commonly keyed and must exclusively be used during LOTO procedures involving a lockbox.

A lockout that involves more than one person; it requires the use of a LOTO hasp for small groups or a lockbox for larger groups. All Authorized Persons must place a lock and tag on the hasp or lockbox to ensure their safety.

A procedure that involves welding on pressurized pipelines, vessels or tanks to install connections or accessories; the procedure is commonly used to replace or add sections of pipeline used in air, gas, water, steam and chemical distribution systems without interrupting service.

 A lock used to ensure continuous energy isolation during a multiple-shift operation for Group LOTO procedures using a lockbox; keys are controlled by each assigned Primary Authorized Person from each shift

The lockbox into which all the Equipment lock keys from the lockout/tagout devices securing EIDs on machines or equipment are inserted; Authorized Persons place their personal locks with tags on the box, securing the Equipment lock keys inside.

Placing a lockout device on an energy-isolating device using an established procedure to make sure the machine or equipment cannot be operated until the lockout device is removed

A device that uses a positive means to hold an energy-isolating device in the "safe" or "off" position; this includes blank flanges and bolted slip blinds. 

Using a machine or equipment for its intended production function

A lock that belongs exclusively to an Authorized Person

An Authorized Person who has overall responsibility for meeting the requirements during a Group LOTO procedure

One who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated their ability to solve or resolve problems relating to the subject matter, the work, or the project.

Activities such as constructing, installing, setting up, adjusting, inspecting, modifying, maintaining, and servicing machines or equipment; it also includes lubricating, cleaning, unjamming, and making tool changes.

Work done to prepare a machine or equipment for normal production operations

Placing a tagout device on an energy-isolating device using an established procedure to indicate that the energy-isolating device and the machine or equipment being controlled may not be operated until the tagout device is removed

A prominent warning device, such as a tag and a means of attachment; it can be securely fastened to an energy-isolating device to indicate that the energy-isolating device and the machine or equipment being controlled may not be operated until the tagout device is removed.

A lock temporarily placed on an equipment energy-isolating device to ensure continuous LOTO protection for employee changes of Authorized Persons or changes between outgoing and incoming shifts