When the job is done, taking off the locks is as risky as putting them on. A person may still be inside the machine. A tool may be left in a gear train. Someone may be about to restart a line without knowing that others are working on it. The standard sets a clear order for returning equipment to service.
Before the devices come off
Under 29 CFR 1910.147(e), before lockout or tagout devices are removed and energy is restored, the authorized employee must check three things.
- The machine or equipment. Inspect the work area. Make sure nonessential items such as tools have been removed. Check that the machine's components are operationally intact, so that guards are back in place.
- The employees. Make sure all employees are safely positioned or removed from the area.
- Notification. Tell the affected employees that the devices are being removed, before the equipment is started.
Only then is the device taken off.
Who removes a lock?
The rule is simple: each lockout or tagout device must be removed by the employee who applied it. The lock is personal. Whoever put it on holds the only key and takes it off.
This rule exists because the person who applied the lock is the only one who knows if they are still working on the machine. A key on a hook or a master key in an office is a danger.
When the person is not there
Sometimes the person who applied the lock has gone home, forgotten to remove it, or cannot be reached. The standard allows removal by someone else only under a specific, documented procedure with training for the people who will use it. The employer must show that this gives protection equal to the usual rule.
At a minimum the procedure must include:
- verification that the authorized employee who put on the device is not at the facility;
- all reasonable efforts to contact that employee and tell them the device has been removed;
- a way to make sure that employee knows about the removal before they resume work at the facility.
Cutting a lock because "it is only a tool change" is not a procedure. A worker who finds a lock they did not put on must not remove it. They should tell their supervisor and leave it to those who use the procedure.
Temporary removal for testing
Sometimes a machine must be energized during maintenance, to test or position it. The standard permits temporarily removing devices in a specific order: clear the machine of tools and materials, remove employees from the area, remove the devices as the procedure says, energize and test, then deenergize and reapply the controls before work goes on.
Lessons from real incidents
Many LOTO injuries happen because someone:
- restarted a machine without knowing that a colleague was inside;
- removed another person's lock or tag;
- took a shortcut because the job looked small;
- did not finish the procedure, for example by skipping verification.
What to remember
- Before removal: check the machine, the people, and notify.
- The person who applied a lock removes it.
- Removal by others is allowed only under a documented procedure with trained users.
- Never remove a lock or tag that is not yours.
- Always give a clear warning before starting the machine.