Environmental Health and Safety


Lockout Tag-Out is a program intended to prevent the accidental re-energizing of equipment during a period of maintenance. The form of energy could be electrical, hydraulic, pneumatic etc. and must be controlled in such a way that stored energy cannot be released during maintenance and the equipment cannot re-energize until work is completed. This is done with the use of accepted devices and blocks that are intended for such purposes and suitable for that intended use.

What is Lockout/Tagout (LOTO)?

  • Lockout occurs when a locking mechanism is placed on a machine to prevent the release of energy during a period of maintenance.
  • Tagout refers to placing a tag on a device or a machine in an effort to notify other employees not to turn on or energize the equipment. Tagout processes should not be used as a sole method of securing a machine and should only be used in the accompaniment of one or several lockout devices on all available lockout points as provided by the machine manufacturer.
  • The process of Lockout/Tagout may also include the use of blocks (blockout) to restrict moving parts or to secure stored energy.
  • An effective Lockout/Tagout program will ensure that all workers who use, service, repair or work in the area close to machinery that is being serviced or repaired remain safe.

What is Required?

Before beginning any maintenance, a written procedure must be created for each piece of equipment that details the process of releasing stored energy, all shutoffs and all areas that a lockout device or block is required. EH&S has provided a template procedure that can be used for this purpose but it will be the responsibility of the department to complete the procedure and ensure it is complete.

Who is Authorized or Affected?

Lockout Tagout can be attributed to the responsibilities of three primary parties as follows. All employees should review the written Lockout Tagout Program at great length for detailed information regarding specific roles and responsibilities and when they are applicable. 

Supervisors: Supervisors are responsible for the supervision of authorized and affected employees as well as monitoring the maintenance of a machine during the lockout period. A supervisor does not need to be a manager by title but can be a designated authorized employee who will assume those duties. Those holding a supervisory roles must also ensure that a written procedure has been created for each piece of equipment prior to attempting any maintenance. Authorized and Affected employees should be trained on those procedures. Additionally, supervisory roles are tasked with the verification of maintenance completion and that all lockout tagout devices are properly removed at the appropriate time, including the added assurance that all maintenance personnel have been accounted for.

Authorized Employees: An authorized employee must be trained on site specific Lockout/Tagout procedures and is authorized to perform Lockout/Tagout procedures on equipment needing service or repair.

Affected Employees: An affected employee is an employee whose job duties include use of equipment that may be locked out during service or repair. The purpose for this role is to effectively notify affected employees when such equipment is under maintenance to prevent accidental re-energizing of equipment during maintenance or the unauthorized bypass of lockout/tagout devices. Authorized employees should remain clear of affected equipment until notified by the supervisory role that the maintenance (lockout/tagout) window is closed.