The word most people hear is “lock”, and it is the least important part. A lockout is the end of a sequence: identify every energy source, shut down, isolate, dissipate stored energy, apply locks, then verify that the machine cannot start by trying to start it. Skipping the last step is the failure mode that kills people who did everything else.
What it means in practice
- Stored energy is where the injuries are. Springs under compression, raised loads, capacitors, hydraulic accumulators, steam, pressurised lines, material that can flow by gravity. Cutting the electrical supply does nothing to any of them.
- One worker, one lock, one key. A group lockout box handles a crew; nobody removes another person’s lock. Written removal procedures for a lock whose owner has gone home exist, and they involve more than a bolt cutter.
- The procedure is machine-specific and written, listing the isolation points by name. A general policy that says “lock out equipment before servicing” is not an energy control procedure.
- Tagout alone is weaker and it is not equivalent. A tag warns; a lock prevents. Where isolation devices cannot accept a lock, the additional measures have to be documented.
- Contractors are the recurring gap — different locks, different procedure, same machine. Coordination is the prime contractor’s or constructor’s problem before it is a maintenance problem.
What it is not
It is not required for normal production adjustments in every case — but the exceptions are narrow, defined in the regulation, and they are where employers over-read their freedom. Clearing a jam is service work far more often than managers assume.
It is not confined to electricity. Half the isolation points on a typical line are pneumatic, hydraulic or gravitational.
And it is not the same duty everywhere in Canada. The federal Code and each province write the requirement differently, and standards such as CSA Z460 fill in the detail without themselves being law. A corporate LOTO standard has to be checked against the jurisdiction it is applied in, not against head office.