The exact lockout/tagout procedures will look different from company to company, but include many of the same steps.
Employees must follow each of the steps exactly and in order to assure that they stay safe. These steps must occur before beginning service or maintenance on machinery or equipment covered by LOTO standards.
- Prepare for shutdown. This includes making sure the correct equipment has been identified for LOTO.
- Notify employees, alerting any workers who use or will be around that machine that will be locked or tagged out. Let workers know how long the work is expected to take and when the machine will be available for use.
- Shut down the machine, following the specific and detailed instructions provided by the employer.
- Disconnect or isolate the machine from its energy source or sources, including electricity, steam, water, gas, compressed air and others.
- Release or restrain any stored or residual hazardous energy. This can include trapped heat in a thermal system, excess fumes or tension in a spring assembly.
- Apply the lockout and/or tagout devices.
- Verify that all the steps were completed and the machine is safe. Try starting the equipment to be sure the lockout is working.
Once the machine has been serviced or is ready to be put back into use, the employee who applied the lockout/tagout devices should follow these steps (only the employee who applied the LOTO devices may remove them):
- Inspect the machinery or equipment to make sure that it is still intact and the area is clear.
- Make sure everyone is away from the machines, and once they remove the device, be sure that any workers that use that machine know that the lockout/tagout devices have been removed.
When it’s not possible to lockout a device, employers can implement tagout procedures instead. OSHA considers tags as less secure than locks, because tags just warn of danger, while locks provide an actual physical restraint. Tagout procedures include:
- Adding at least one other safety measure that prevents re-energization, such as removing an isolating circuit element, blocking a control switch or opening an extra disconnecting device.
- Applying a tagout device.
OSHA only allows employers to use tagout systems instead of lockout systems if the employer can prove the tagout system is just as effective as a lockout system.
Lockout/tagout safety procedures also apply to special circumstances. When an employer uses an outside contractor for service or maintenance, the employer and contractor should educate each other on the lockout/tagout procedures each uses. The employer must then pass that information on to the employees.
Sometimes maintenance is done by a group of workers rather than one person. In these instances, each worker takes control of the hazardous energy source when directly involved in service or maintenance. One worker from that group is the authorized worker, with the responsibility for applying and removing the lockout/tagout device.
Most group lockout programs have a lockbox or other central place where each person working on the machine or system can attach his or her lock. Only when there are no locks on the lockbox (I.e. no one is still working) can the Authorized Person get to the keys necessary to remove locks and put the system back into service.
If maintenance takes place during a shift change, the employer should name an authorized worker for the second shift who takes on the responsibility of removing lockout/tagout devices. The authority moves from the first shift authorized worker to the next shift’s authorized worker.
At times a lockout device or tag may be left on inadvertently. When this happens, the other employees should follow these steps:
- Contact the authorized person’s supervisor
- Double-check the person is no longer on site
- Try to contact the person via cell phone or at their home
- When not able to contact that person, management will authorize the removal of the lockout/tagout following the written emergency removal procedures
- Document the removal and let the authorized worker know of the removal
Tools and Supplies
The lockout/tagout procedure requires using physical tools and supplies, some for the lockout portion and others for the tagging portion. Examples of lockout devices include locks and keys and restraints, while tagout devices include warning signs, tags and management software.
Each piece of equipment or machinery can only have one device to control hazardous energy and employer must provide enough lockout/tagout devices for every machine that needs it.
Regardless of what type of device an employer uses, it must be:
- Durable to withstand workplace conditions including exposure to extreme heat or cold, UV rays, moisture, humidity, high winds or industrial chemicals
- Unable to be removed without excessive force
- Different from any other non-LOTO devices in color, shape, and size
- Not used for any other purposes
- Legible and understandable by all employees
- Not able to be removed accidentally or prematurely
Locks should only have one key or one combination, kept in the possession of just one person (the authorized worker). The lock should also include the authorized employee’s contact information such as name, department and phone number.
It’s recommended that lockout locks be a different color (such as red or orange) so that employees can easily tell them apart from standard security locks.
Tags have to be non-reusable, self-locking, non-releasing up to 50 pounds, attachable by hand and attached with one-piece nylon cable tie or a similar piece. The tag should have some type of warning printed on it, such as “Do not use” or “Do not operate”.
Employers should inspect lockout/tagout devices regularly and replace as needed. An employee must be sure they are only using devices approved for each type of machinery or equipment and following the instructions for those devices.
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