Picture yourself working inside a huge machine, tending to its maintenance. Suddenly the machine springs to life, powerful metal gears grinding around you, placing you in mortal danger.
That is exactly the sort of terrifying scenario that lockout/tagout is meant to prevent. Lockout/tagout is a procedure to disable equipment to protect workers from either an unexpected release of energy or an accidental start-up while performing job activities.
During lockout/tagout, a person authorized by the company places locks and/or tags on energy-isolating devices before working on equipment, and only that person can remove those locks and tags. Isolation devices are mechanical appliances, such as circuit breakers, used to stop energy from being released to the equipment. Lockout is usually accomplished with a keyed lock holding an isolating device in an “off” position. Tagout, which is often used when lockout cannot take place, uses tags to warn people that the equipment and isolating device may not be operated.
Lockout/tagout in the workplace
Lockout/tagout is required when servicing or performing maintenance on equipment. Effective lockout/tagout should occur in three phases: applying lockout/tagout, servicing and repairing equipment, and returning equipment to proper operation.
Applying Lockout/Tagout: An authorized worker should notify others in the area that lockout/tagout procedures will be taking place. After listening to instructions given by the authorized worker, all unauthorized personnel should move to a safe location, away from the equipment.
Note: Locks and tags must identify the authorized worker who put it on the equipment that is going to be serviced or maintained. Unauthorized personnel cannot attach or remove locks or tags on behalf of authorized workers.
Servicing and Repairing Equipment: Unauthorized personnel should stay away from the equipment while the authorized person is working on it. At this time, the equipment is at its most vulnerable to the unexpected release of hazardous energy.
Returning Equipment to Proper Operation: During this phase, the authorized worker should tell others in the area when locks and tags will be removed. Workers should stay clear of the area while locks and tags are removed and the equipment is prepared for normal operation. All personnel should be informed when lockout/tagout is complete.