The lockout/tagout standard does not apply to everything a worker does around a machine. Knowing where it stops is part of staying safe. A job that falls outside the standard may still need protection of another kind.
Normal production operations
The standard covers servicing and maintenance, not the normal production operations of a machine. During normal production, the machine's guards, interlocks and the operating controls protect the operator.
Servicing and maintenance that takes place during normal production is covered by the standard only if an employee must:
- remove or bypass a guard or other safety device; or
- place any part of their body into the point of operation, or into a danger zone associated with the machine's operating cycle.
If either is true, lockout or tagout applies even if the work is quick.
The minor servicing exception
Some jobs are so routine that stopping and locking out would make production almost impossible. The standard exempts minor tool changes and adjustments, and other minor servicing activities, but only when the work is:
- done during normal production operations;
- routine and repetitive;
- integral to the use of the equipment for production;
- and carried out using alternative measures that give effective protection, such as interlocked guards.
The exception is narrow. A job that is not routine, such as clearing a one-off jam or replacing a part, is not minor servicing just because it is short. If you are unsure, treat it as lockout.
Cord-and-plug equipment
Equipment powered by a cord and plug is not covered when unplugging it removes the hazard and the employee doing the servicing has exclusive control of the plug. For example, the worker unplugs a bench grinder and keeps the plug in their hand or pocket. If someone else could plug it back in, a lock or other control is needed.
Hot tap operations
The standard also exempts "hot tap" work on pressurized pipelines such as gas, steam or water, but only when continuous service is essential, shutdown is impractical and documented procedures and special equipment give effective protection.
Electrical work: 29 CFR 1910.333
Electrical hazards from electrical installations are covered by Subpart S, not by 1910.147. The key rule for deenergized circuits is 29 CFR 1910.333(b).
- Equipment that is deenergized but not locked out or tagged is treated as energized.
- Employers need written lockout and tagging procedures, and the steps must be followed in order.
- A lock and a tag go on each disconnecting means. A tag alone is allowed only in limited cases, such as where a lock cannot be applied, and then with an extra safety measure.
- Stored electrical energy must be released, and stored non-electrical energy that could reenergize the circuit must be blocked or relieved.
- A qualified person must verify with test equipment that the circuit is dead, including a check for induced or backfeed voltage.
Electrical safety training is covered by 29 CFR 1910.332. Employees at risk of electric shock must know the safe work practices for their jobs. Those who work on or near exposed live parts must be trained as qualified persons.
Other settings
Construction work, utilities and other industries are governed by their own OSHA standards, such as 29 CFR 1926 for construction and 29 CFR 1910.269 for electric power generation, transmission and distribution. Ask your employer which one covers your job.
What to remember
- Lockout applies during production when you bypass a guard or put any body part into a danger zone.
- The minor servicing exception is narrow and needs alternative protection.
- Cord-and-plug equipment is exempt only if you have exclusive control of the plug.
- Electrical circuits that are not locked out or tagged are treated as energized.