Lockout/tagout procedures are safety measures used to prevent the unexpected energization or startup of machinery and equipment, or the release of stored energy, that could cause injury to employees. Lockout involves physically locking energy-isolating devices in a safe position, while tagout uses warning tags to indicate that the equipment should not be operated. These procedures involve communication, coordination, and training to ensure safety during maintenance or servicing. An effective lockout/tag out program will help prevent:

• Contact with a hazard while performing tasks that require the removal, by-passing, or deactivation of safeguarding devices.
• The unintended release of hazardous energy (including stored energy).
• The unintended start-up or motion of machinery, equipment, or processes. [3] [8]

Here are the general steps of a lockout/tag out procedure:

1. Prepare for Shutdown: The authorized person identifies the machine, equipment, or process that requires lockout, the sources of energy that are present and must be controlled, and what lockout device will be used. This includes gathering all required equipment (e.g., lockout devices, tags, etc.). 2. Notify all Affected Personnel: The authorized person communicates what is going to be locked/tagged out, why, for approximately how long the system will be unavailable, who is responsible for the lockout/tag out, and who to contact for more information. This information should also be present on the tag required for the lockout. 3. Equipment Shutdown: Follow shutdown procedures (either established by the manufacturer or employer). Equipment shutdown involves ensuring controls are in the off position and verifying that all moving parts have come to a complete stop. 4. Isolation of System (De-energization): Follow the lockout procedure for the identified machine, equipment, or process. Practices include:

• Electrical energy - Switch electrical disconnects to the off position and visually verify that the breaker connections are in the off position. Lock the disconnects into the off position. NOTE: Only disconnect switches or breakers that you are trained or authorized to do so, especially at high voltages.
• Hydraulic and pneumatic potential energy - Setting the valves in the closed position and locking them into place only isolates the lines from more energy entering the system. In most cases, residual energy will still be left in the lines as pressurized air or fluid. This residual energy can be removed by bleeding the lines through pressure relief valves. Verify depressurization or use flange-breaking techniques. Contact the manufacturer for more specific details, or if no pressure relief valves are available, what other methods are available.
• Gravitational potential energy - If possible, bring the equipment or machine to ground level.
• Chemical energy - If available, bleed lines and/or cap ends to remove chemicals from the system. [2] [7]

When the system's energy sources are locked out, specific guidelines to follow include:

• Each lock should only have one key (no master keys are allowed).
• All keys must be removed from locks and kept with the person who applied the lock.
• There should be as many locks on the system as there are people working on it. For example, if a maintenance job requires 3 workers, then 3 locks should be present - each individual must place their OWN lock on the system. Locks can only be removed by those who installed them and should only be removed using a specific process.
• Verify that the system is properly locked out before beginning any work. The machine, equipment, or process controls (push buttons, switches, etc.) are engaged or activated, and the result is observed. No response means isolation is verified. Return controls to the safe position (off). [7]

NOTE: Notification must be given to affected employees before and after the controls are applied to the machine or equipment. Before starting work on machines or equipment that have been locked out or tagged out, the authorized employee must verify that isolation and de-energization of the machine or equipment have been accomplished. [1] [5]

Before lockout or tagout devices are removed and energy is restored to the machine or equipment, the following must be ensured:

• The work area is inspected to ensure that nonessential items have been removed and that machine or equipment components are operationally intact.
• The work area is checked to ensure that all employees have been safely positioned or removed.
• Affected employees are notified that the lockout or tagout devices have been removed. [4]

Each lockout or tagout device must be removed from each energy isolating device by the employee who applied the device. However, if that employee is not available to remove it, the device may be removed under the direction of the employer, provided that specific procedures and training for such removal have been developed, documented, and incorporated into the employer's energy control program. The specific procedure must include at least the following elements:

• Verification by the employer that the authorized employee who applied the device is not at the facility.
• Making all reasonable efforts to contact the authorized employee to inform him or her that his or her lockout or tagout device has been removed.
• Ensuring that the authorized employee has this knowledge before he or she resumes work at that facility. [4]

Lockout devices and tagout devices must:

• Be singularly identified
• Be the only devices used for controlling energy and may not be used for other purposes
• Be capable of withstanding the environment to which they are exposed for the maximum period of time that exposure is expected
• Be standardized within the facility in at least one of the following criteria: color, shape, size. Additionally, in the case of tagout devices, print and format must be standardized.
• Each lockout device or tagout device shall include provisions for the identification of the employee applying the device.
• Tagout devices must warn against hazardous conditions if the machine or equipment is energized and include a legend such as the following: Do Not Start, Do Not Open, Do Not Close, Do Not Energize, Do Not Operate.

[6]