Lockout/Tagout Awareness Course: Lessons 2026

Lesson 1: What hazardous energy is

Machines need energy to run. When someone cleans, repairs or adjusts a machine, that energy can hurt them if the machine starts up or moves without warning. The CSA standard CSA Z460, Control of hazardous energy — Lockout and other methods, describes hazardous energy as any electrical, mechanical, hydraulic, pneumatic, chemical, nuclear, thermal, gravitational or other energy that can harm people.

Stored energy

Turning a machine off does not always make it safe. Residual or stored energy can stay behind, such as pressure left in a line, a charged capacitor, or a part held up in the air. CCOHS warns that not dealing with stored energy can cause injuries. It must be released, blocked or drained before work starts.

Lesson 2: Lockout, tagout and the devices used

Lockout means putting a lock on an energy-isolating device by following a set procedure. The lock holds the device in the safe (off) position so the machine cannot be turned back on.

Energy-isolating devices include disconnect switches, circuit breakers, line valves and blocks. Push buttons, selector switches and other control switches are not energy-isolating devices. Pressing stop on a control panel does not lock anything out.

A tag is used with the lock. It tells everyone why the lockout is in place, when it was put on and the name of the authorized person who applied it. CCOHS says tagout is always used when lockout is required. A tag on its own does not stop anyone from turning the power back on.

Rules for locks and keys

• Each worker puts their own personal lock on the system. Three workers means three locks.
• Each lock has one key. Master keys are not allowed.
• The worker keeps control of their key for the whole job.
• Each personal lock is marked or tagged to show who put it on.
• Only the person who put a lock on may take it off, except under a special removal procedure.

CCOHS describes two roles in a lockout program. An authorized person has the knowledge, training and experience to do lockout and has been assigned the job. An affected person works near the equipment or uses it, but does not do the lockout.

Lesson 3: The steps of a lockout

Every machine needs its own written procedure, but the main steps are the same. CCOHS lists them in this order:

1. Prepare: identify the equipment, every energy source and the devices needed.
2. Notify: tell affected people what is being locked out, why and for how long.
3. Shut down: stop the machine the normal way and wait until all moving parts stop.
4. Isolate: open disconnects, close valves and block parts for each energy source.
5. Release stored energy: bleed pressure, discharge capacitors and lower raised parts.
6. Lock and tag: each worker applies a personal lock and tag.
7. Verify: test that the machine will not start before anyone begins work.
8. Do the work.
9. Remove devices and restart: check the area, make sure everyone is clear, remove locks in reverse order and tell affected workers.

Verifying isolation

Verifying is the step that proves the lockout works. A common method is to try the normal start controls while watching and listening, then return the controls to off. Alberta's explanation guide calls this a "bump" test. BC's regulation says a worker must verify that all energy sources are locked out before starting work.

Lesson 4: What the law says

Each province and territory sets its own rules for lockout in its OHS laws, and many follow CSA Z460. Here are two examples.

British Columbia: OHS Regulation Part 10

• When machinery is shut down for maintenance, no work may be done until the energy-isolating devices are locked out (s. 10.3).
• Locks are applied by following procedures made available to all workers who must work on the machinery, and each worker who must lock out has enough personal locks (s. 10.4).
• A worker must verify that all energy sources are locked out before work begins (s. 10.6).
• Each worker keeps immediate control of the keys to their personal locks for the whole job (s. 10.7).
• A personal lock may only be removed by the worker who put it on (s. 10.8).
• If that worker is not available, a supervisor or manager must make every reasonable effort to contact them and make sure the equipment is safe. The worker is told at the start of their next shift (s. 10.8).

Alberta: OHS Code Part 15

Alberta's OHS Code Part 15, Managing the Control of Hazardous Energy, has sections on isolation, verifying isolation, personal locks, group control and returning equipment to operation. Equipment must be stopped and isolated before work such as servicing or repairing it.

Group lockout

When many people work on a large system, a group procedure may be used. In Alberta's version, a designated worker locks the isolating devices and puts the keys in a lock box. Each worker then puts a personal lock on the box. The keys cannot come out until every personal lock is off.

Lesson 5: Lockout awareness for guards and other workers

Many workers never apply a lock but still work near locked-out equipment. Security guards often patrol plants, warehouses and construction sites at night when maintenance is done. You need to recognize a lockout and leave it alone.

Do and do not

• Do not remove, cut or move anyone's lock or tag, even if it looks forgotten.
• Do not press start, flip a breaker or open a valve on locked-out equipment.
• Do report a lock or tag that looks damaged, tampered with or has no name.
• Do report anyone who tries to remove a lock that is not theirs.
• Do write in your notes where you saw lockouts and anything unusual.

If you think equipment is unsafe, tell your supervisor right away. Never try to restart it yourself. Restarting is part of the trained worker's procedure, after the area is checked and everyone is clear.

Training required by law

Lockout is skilled work. CCOHS says employers must train workers on their roles in the hazardous energy program, and supervisors must make sure only trained people do lockout work. This course is background knowledge only. It does not make you an authorized person and does not replace your employer's training on its own procedures.