OSHA 1910.147 in plain words

What it covers

Servicing and maintenance of machines and equipment in general industry, where someone could be hurt if the machine starts up unexpectedly or releases stored energy. That includes clearing jams, cleaning, adjusting, changing tooling and repair. Normal production work is covered only when a guard is removed or bypassed or a person puts part of their body where the machine works.

It does not cover construction or agriculture, which have their own rules, or work on cord-and-plug equipment when it is unplugged and the plug stays under the control of the person doing the work.

What the employer has to have

• An energy control program: procedures, training and periodic inspections, so machines are isolated and made inoperative before anyone works on them.
• Written procedures for each machine (c)(4), unless a machine meets every condition of the single-source exception. Each one states its intended use, the steps to shut down, isolate, block and secure the machine, the steps to place, remove and transfer locks and tags, and how to verify that the lockout worked.
• Lockout devices (c)(5): provided by the employer, used only for energy control, durable, standardized by color, shape or size, substantial enough that they cannot be removed without excessive force, and identifying the person who applied them. Tags are used alone only where a device cannot take a lock.
• Training (c)(7): authorized employees learn to recognize the energy sources, their type and magnitude and how to isolate them; affected employees learn what lockout is for and never to restart a locked machine.
• A periodic inspection (c)(6) of every procedure at least once a year, by an authorized employee who is not using it. See the annual inspection.

The six steps of applying a lockout, (d)

1. Prepare. Know the type and magnitude of the energy, its hazards and how to control it.
2. Shut down the machine the normal way.
3. Isolate it: operate every energy-isolating device.
4. Lock and tag each isolating device.
5. Release stored energy: relieve, disconnect, restrain or otherwise make safe anything left, such as air, oil, springs, heat or charge. If it can build back up, keep checking until the work is done.
6. Verify the machine is isolated and de-energized before the work starts.

Affected employees are told before the lockout and after it is removed.

Release from lockout, (e)

Check the machine is intact and tools are cleared, make sure everyone is safely positioned, tell the affected employees, and have each lock removed by the person who put it on. If that person is not at the facility, the standard allows a specific employer procedure for removing it.

The special cases, (f)

• Testing or positioning with the power on: clear the machine, remove people, remove the devices, test, then de-energize and lock out again before work continues.
• Outside contractors: the plant and the contractor tell each other their procedures.
• Group lockout: one authorized employee in charge, each person on their own lock, for example on a group hasp or lockbox.
• Shift changes: the lockout is transferred so that the machine is never left without protection.

This is a plain-language summary, not legal advice. The text of 29 CFR 1910.147 is the rule.