Lockout/tagout: isolating machinery safely in a Victorian factory

What is lockout/tagout and when is it required?

Lockout/tagout is the process of isolating, de-energising and physically locking machinery before maintenance, repair, cleaning or adjustment work begins, with a tag identifying who did it and why. Victorian employers must isolate, de-energise, lockout and tagout plant before this kind of work, so machinery can't unexpectedly restart or release stored energy while someone's in the danger zone.

What's the legal basis for lockout/tagout in Victoria?

Employers have a duty under the Occupational Health and Safety Act 2004 (Vic) to provide and maintain a working environment that is safe and without risks to health, so far as is reasonably practicable. The Occupational Health and Safety Regulations 2017 (Vic) require that hazards associated with the use of plant be identified and that action be taken to control the risks, with duties also placed on designers, manufacturers and suppliers of plant (WorkSafe Victoria).

Do you need a risk assessment before locking out a machine?

Yes. Lockout and tagout shouldn't be the first thing you reach for — a risk assessment needs to happen first, to work out whether the plant can be made safe some other way, such as through substitution, permanently fixed guards or an interlocked system. Lockout and/or tagout is an option when those higher-order controls aren't reasonably practicable (WorkSafe Victoria). This reflects the general hierarchy of controls, adapted to plant isolation under the OHS Regulations 2017: elimination first, then substitution, isolation or engineering controls (including guarding and interlocks), then administrative controls (including lockout-tagout systems, supervision and training), then PPE.

What are the basic steps in an isolation procedure?

WorkSafe Victoria sets out steps that every plant isolation procedure should cover, in order:

1. Shut the plant down — using the relevant switch, valve or shutdown sequence.
2. Identify all energy sources and other hazards — including electricity, fuel, heat, steam, fluids under pressure, stored energy, gravity and radiation.
3. Identify all isolation points — every point needed to isolate energy for the plant, noting that emergency stop buttons alone are not adequate isolation points.
4. Isolate all energy sources — a competent person, such as an electrician, should isolate plug-and-socket connected equipment from all electricity supply, not just the control circuit.
5. De-energise all stored energy — relieving trapped pressure, blocking spring-driven parts, draining lines, and similar steps depending on the plant.
6. Lock out all isolation points — using padlocks, safety hasps, lockable switches or valve lockouts.
7. Tag the isolation point — a tag on its own is not an isolation device; it only communicates information, so a lock should always be the actual isolation control.
8. Test the isolation — confirm with instruments, then attempt to restart the plant, before anyone begins work (WorkSafe Victoria).

What's the difference between a lock and a tag?

A lock is the physical isolation device. A tag is information only — it tells others who isolated the plant, when, and why, but it doesn't stop the plant from being restarted. WorkSafe Victoria is explicit that a tag should never be relied on as a substitute for a lock. Two tag types are commonly used:

• Personal danger tags — attached by the person doing the work, identifying them and warning that operating the equipment could endanger them. Only that person should remove their own tag.
• Out of service tags — indicate plant is unserviceable and shouldn't be used, for reasons unrelated to a specific person's immediate safety, such as awaiting parts.

The two tag types shouldn't be used together on the same isolation point, because they relate to different circumstances (WorkSafe Victoria).

What is the "one person, one lock" principle?

If more than one person is working on the same plant, each person attaches their own lock so the energy isolator can't be reopened until every lock has been removed. Where several lockout points are involved, each worker locks and tags each point, or a lock box system is used so a single lock per isolation point is needed while each worker's individual lock secures the box holding the keys. Each worker should hold only the key to their own lock, with no duplicates available except a secured master key for emergencies (WorkSafe Victoria).

Where this goes wrong on Victorian factory floors

The most common failure I see isn't a missing lock — it's a missing risk assessment, or a procedure that was written once and never updated as plant changed. Isolation procedures need to be documented, accessible, and specific to the plant in front of the worker, with training for everyone who operates, cleans, maintains or inspects it. A safety practitioner reviewing your isolation procedures against current plant configuration is one of the fastest ways to find gaps before an inspector does. If that's useful for your site, book a site assessment.

FAQ

Is a tag alone ever enough to isolate machinery? No. WorkSafe Victoria treats a tag as information only, not an isolation device — a lock, or equivalent physical isolation control, should be used, with a tag attached to explain the purpose of the lockout.

Can an emergency stop button be used as an isolation point? No. Emergency stop buttons, lanyards and similar stop devices aren't satisfactory isolation points on their own — they're not designed for frequent use, can't always be locked out, and may still leave control circuits live.

Who should isolate electrical equipment connected by plug and socket? A competent person, such as an electrician, should isolate and disconnect the entire electricity supply, not just the control circuit, to make sure the equipment can't be energised through another source or control system.

This article is general information for Victorian manufacturers, not legal advice. Last updated: 10 August 2026.