---
title: "Lockout / tagout — hazardous energy control, not a padlock"
description: "What lockout and tagout are, the difference between the two, what a written energy control procedure has to contain, and why the padlock is the last step rather than the first."
term: "Lockout / tagout"
definition: "The controlled isolation of every energy source feeding a machine before service or maintenance, with each worker applying a personal lock, and a tag identifying who applied it and why. It is a written procedure verified by a zero-energy test, not simply a lock on a switch."
alsoKnownAs:
  - "LOTO"
  - "Hazardous energy control"
  - "Lock-out tag-out"
jurisdiction: "Canada"
locale: "en-CA"
publishedOn: 2026-09-06
reviewedOn: 2026-09-06
canonical: "https://safeally.net/en-ca/glossary/lockout-tagout/"
sources:
  - label: "Hazardous energy control programs"
    url: "https://www.ccohs.ca/oshanswers/hsprograms/lockout.html"
    publisher: "CCOHS"
  - label: "OHS Regulation, Part 10 — de-energization and lockout"
    url: "https://www.worksafebc.com/en/law-policy/occupational-health-safety/searchable-ohs-regulation/ohs-regulation/part-10-de-energization-and-lockout"
    publisher: "WorkSafeBC"
  - label: "Industrial Establishments, R.R.O. 1990, Reg. 851"
    url: "https://www.ontario.ca/laws/regulation/900851"
    publisher: "Government of Ontario"
---

# Lockout / tagout — hazardous energy control, not a padlock

The controlled isolation of every energy source feeding a machine before service or maintenance, with each worker applying a personal lock, and a tag identifying who applied it and why. It is a written procedure verified by a zero-energy test, not simply a lock on a switch.

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.