Environmental Health & Safety

Control of Hazardous Energy

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Control of Hazardous Energy (Lockout/Tagout)

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1. PURPOSE
2. PERSONNEL AFFECTED
3. DEFINITIONS
4. RESPONSIBILITIES
5. PROCEDURES



The key to lockout/tagout procedures is VERIFICATION that the appropriate energy source(s) is locked out, the system is in fact de-energized, and pressure is safely relieved.

Typical operations covered by lockout/tagout include, but are not limited to, working on:

• electric motors and circuits
• water lines, steam lines and boilers
• refrigeration and air conditioning equipment
• permanently wired machinery or equipment including ovens
• wood planers, table and radial saws or other shop and laboratory equipment
• pressurized and non-pressurized liquid or chemical lines
• compressed air or gas lines, natural gas lines
• hydraulic/pneumatic systems
• elevators/hoists/overhead cranes
• overhead doors and dock plates

A piece of equipment can have more than one type of energy associated with it. For example, it might have an electric motor (electrical), pressurized steam lines (pneumatic and thermal energy) and pistons (mechanical energy).

It is important to identify all the sources of energy and control them by ensuring they are all de-energized and placed in a safe and secure position before beginning work on any equipment.

Stand behind or to the side of the work when opening pipe lines, throwing switches or opening panels regardless of type of energy, even though the source is believed to be isolated and energy relieved.

Only authorized employees may conduct the lockout/tagout procedure.

1. Specific Procedures
1. General Procedures
1. The Authorized Lockout/Tagout Employees performing the work must create the work plan or lockout procedures, and physically locate and identify all isolating devices to be sure which switches, valves, or other energy isolating devices apply to the equipment to be locked out.

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

1. the machine or equipment has no potential for stored or residual energy or reaccumulation of stored energy after shut down which could endanger employees;
2. the machine or equipment has a single energy source which can be readily identified and isolated;
3. the isolation and locking out of that energy source will completely deenergize 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 reenergization of the machine or equipment during servicing or maintenance
2. A job hazard analysis shall be completed for all tasks requiring a LOTO procedure but where none exists.
3. Notify all affected and other Employees as necessary that a lockout is to be performed. These persons must be instructed that they are not to disturb the lockout device or attempt to re-start the equipment until they are informed that the lockout has been cleared and it is safe to resume normal operations.
4. If the equipment is in operation, shut it down using the normal shutdown procedure. Turn the equipment off if there is an off/on switch.
5. Turn energy isolation devices (disconnects, valves, etc) to the “off” position. Toggle switches, push buttons, interlocks and other types of control switches are not energy isolating devices.
6. All energy-isolating devices must be locked out. Lock isolating device in the “off” position with an assigned individual lock, and attach an identifying tag to the lock. (See Appendix A). Use only the lock issued for this purpose. The key shall remain under the control of the authorized person performing this operation.  If it is impossible to use a lock, use a tag after notifying Occupational Safety and receiving approval.
7. All forms of stored energy must then be dissipated (except for batteries which can be disconnected). This may include relaxing any springs, relieving any pressure or vacuum, allowing flywheels to come to rest, discharging capacitors, or neutralizing or adequately removing any chemicals.
8. Any parts that could inadvertently move during the procedure must be blocked in place to prevent this movement. Blocking must be secured in place so that it cannot be inadvertently removed or fall out. Fan blades might need to be blocked to prevent freewheeling, and the blocking device (e.g. clamp, wedged 2x4, etc.) tagged.
9. VERIFY all forms of hazardous energy have been reduced to zero energy potential by means of testing, gage readings, opening valves to slowly release pressure, observing and fixing as necessary a spring in a relaxed state, observing that a flywheel is not spinning, using litmus paper to verify the absence of chemical, etc.. Note that gauges are indicators only of pressure content, can fail and should not be solely relied on to convey a zero energy state.
10. Attempt to re-start or re-energize the equipment or machinery to verify an isolated condition. If the equipment re-starts or it appears that energy has been allowed to flow into the system, no work should proceed until the problem is identified and appropriate steps are included in the procedure to control this energy.
11. If a zero energy state is VERIFIED and the controls are locked and tagged out work may begin.
2. Situations Involving More Than One Person Locking Out

   If more than one employee works on the equipment, a lockout adaptor suitable for the installation of several locks must be used, enabling all workers to lock out the machine or energy source with their individual locks. Each locking device and lock must be identified and tagged by the person locking it. Each person must verify the proper LOTO himself or herself.

3. Procedure Involving Personnel Changes During The Job

   Persons being replaced or exchanged on a job during a shift or at the end of a shift must ensure that the lock(s) and tag(s) of his/her replacement are substituted for his/her own before leaving the job or removing their devices.

   If a lockout procedure is to continue through the following work shift, the oncoming work crews must place their locks and tags on the energy isolating devices before the departing crew removes their locks and tags. Before work begins on the subsequent work shift, the oncoming crew must re-verify that all safety devices, such as blocking, are in place, that there is still zero energy in the system.

4. Procedure When Work Is Left Unfinished

   Locks, tags, and all other safety warning devices must be left in place during all short absences.  When work is incomplete and temporarily suspended, such as overnight or over a weekend, all locks, tags, and other safety warning devices must be left in place. When work is suspended for an extended period of time, the equipment or machinery must be permanently disconnected from all energy sources and tagged as out of service. Lockout/tagout devices must be removed.

5. Procedure When One Employee Leaves The Area Without Removing His/Her Lock

   When an employee leaves the facility site and does not remove his/her lock(s) from the energy isolating device(s), for example due to sickness, vacation, termination of employment, etc., the responsible supervisor must attempt to contact that employee to determine if he/she will be able to return to remove the lock. If the employee is unavailable or cannot return, the supervisor must complete the Abandoned Lock Removal Authorization Form (Appendix C) and then cut the lock(s) off the energy isolating device(s).

   New LOTO must be implemented by the replacing employee, including verification of zero energy. When the original employee returns to the work site, that person must be informed that their lock was removed and the status of the equipment that was locked out (e.g., returned to service, still under lockout, etc.).

6. Procedure When Physical Locking Is Impossible

   When it is impossible to use a lock, a tagout device must be used in lieu of a lockout along with another positive means of disconnecting the circuit, equipment, or machinery. This can include unplugging the equipment (or locking out the plug), disconnecting the conductors, or removing fuses.

   All other steps of the process are the same as those listed above for lockout. A tagout device must be placed on the plug, conductors, disconnect switch, fuse brackets, or other positive means employed.

7. Procedure When Machine Testing Is Required During A Lockout

   On some machines, it may be necessary to energize or start up machinery or equipment during a lockout procedure to troubleshoot, tune, adjust, or make measurements before the machine is fully restored to service. In such cases all persons must clear the hazard zone of all tools and equipment, leave the hazard zone, verify that all persons are clear of any hazards, remove the necessary locks, and then the equipment can be energized. A qualified person must then make the necessary measurements or adjustments and then the equipment shut down. The locked-out condition must then be re-established by repeating the exact same work steps specified on the written procedure for fully locking out the equipment.

8. Restoring Equipment To Service
• Remove all blocking and replace any critical parts removed during the lockout procedure.
• Ensure that all tools or equipment have been removed from the hazard zone.
• Close and secure all cover panels and doors, and/or replace all equipment guards.
• Advise all affected and other employees that the system is to be re-energized.
• Ensure all persons are clear of the equipment/hazard zone.
• Remove locks and tags.
• Energize the equipment and restore the equipment to the normal condition.
• Notify all affected and other employees that the lockout condition has been cleared and the equipment is ready for use.
2. Other Considerations
1. Certain tasks, such as minor tool changes and adjustments, that are part of normal production operations and can be accomplished without removing protective guards or with the use of tools where the employee is not potentially exposed to hazardous energy or inadvertent start up of the equipment, and the equipment start control is under the control of the operator,  (e,g. changing drill press bits where the power switch is shutoff and controlled by the operator) can be allowed.
2. Where it is ABSOLUTELY necessary to work on “live” electrical components, follow the procedure outlined in the UR Electrical Safety program.
3. In addition to the above, other considerations are not limited to but may include:
1. Pressurized Systems: (Compressed Air / Gasses / Hydraulic Fluids / Steam / Pressurized Water, etc.)

   Procedures to dissipate stored or residual energy must be implemented in pressurized systems. The machine or equipment must be returned to a “zero energy state” by methods such as opening drains, relieving pressure, blocking, bleeding, or cycling the system.

   Equipment activated by compressed air, gases, steam, chemicals or other fluids should have valves that control movement. These valves will need not only to be locked out, but also bled to release any residual pressure to atmosphere. Physically disconnect the equipment from the supply plumbing if possible. If not possible, use double valves or blind off supply lines with appropriate flange plates or pipe caps.

2. Mechanical Energy:
   Block equipment components so they cannot move. Examples of proper energy isolation or restraint include using support rods for counterweights or elevated components, a bar through spokes of a wheel, flywheel or fan blades, wheel chocks for rolling components, wrapping and locking chains around a movable equipment component and locking it to an immovable object, etc.
3. Contractors:
   All outside servicing personnel (e.g. outside contractors) must comply with all applicable lockout/tagout standards or requirements.  Whenever outside servicing personnel (e.g., outside contractors) are to be engaged in activities covered by the scope and application of this procedure, the University and the outside employer shall inform each other of their respective lockout or tagout procedures.
3. Training
1. Any affected employee whose job requires him/her to operate or use a machine or equipment on which servicing or maintenance will be performed, or any other employee who works in an area where such servicing or maintenance will be performed must be trained in the purpose and use of the applicable energy control procedures before working in an area where lockout or tagout is in use.
2. Affected employees or others who might have reason to observe lockout/tagout situations must be informed about the prohibition of restarting and re-energizing machines or equipment that are locked or tagged out.
3. Each authorized person must receive training on the recognition of applicable hazardous energy sources, the type and magnitude of the energy in their work place, and the methods and means necessary for isolation and control.  At a minimum the training will include:
1. The identification of hazards, purpose and use of energy control procedures
2. Annual refresher training
3. Explanation of the UR specific lockout/tagout policies and procedures
4. Demonstration of and hands-on use of lockout devices and tags
4. Retraining shall be provided on an annual basis and when:
1. New hazards are presented by the use of new equipment or machines
2. There is a change in policy or procedure
3. An affected or authorized employee's job duties or assignments change
4. A review or evaluation reveals a program deficiency
4. Records

   The departments of those receiving lockout/tagout training are responsible for ensuring their employees receive the appropriate training and the maintenance of their training records. Records pertaining to this lockout/tagout program must be maintained for at least the period the employee is conducting, performing, affected by, or observing this type of work.

   Work areas with lockout/tagout procedures must maintain a file of lockout/tagout equipment specific procedures developed by each supervisor for their specific jobs and equipment.

6. REFERENCES
7. APPENDICES/FORMS
   Appendix A: Lockout/Tagout Tags and Locks
   Appendix B: Equipment Specific Lockout/Tagout Procedure Development Form
   Appendix C: Abandoned Lock Removal Form
   Appendix D: Lockout/Tagout Evaluation Checklist
8. REVISION HISTORY

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This page last updated 5/21/2018. Disclaimer.