A tag on a machine is a small piece of card carrying an outsized instruction: do not use this. On a busy site where an elevating work platform might be shared between crews and shifts, the tagging system is how a fault found by one person is communicated to everyone who comes after, and how a machine known to be unsafe is kept firmly out of the air until it is fixed. This guide explains the difference between an out-of-service tag and a danger tag, how a defect triggers a tag-out, and why the rules on who removes a tag are as important as the rules on who applies one.
What a tag actually does
Tagging is a communication tool built for a plain reason: a fault is only useful information if it reaches the next operator before they climb aboard. A tag attached to the controls converts a private discovery into a public warning that cannot be missed by anyone about to start the machine.
The system relies on the tag being visible, durable and specific. A tag hung where an operator will see it before touching the controls, filled out with what is wrong and who found it, does its job. A vague or hidden tag does not, which is why the discipline of tagging well matters as much as the decision to tag at all.
Out-of-service versus danger tags
Two kinds of tag do related but distinct jobs, and confusing them weakens both.
- An out-of-service tag marks a machine as unfit for use — it has a fault, is awaiting inspection or is otherwise not to be operated until cleared. It tells everyone the equipment is parked for a reason.
- A danger tag is a personal warning attached by an individual who could be harmed if the machine were operated, typically while they work on or around it. It signals that starting the machine could injure the person who placed the tag.
- The two are often used together with an isolation process, where the danger tag protects the person doing the work and the out-of-service tag keeps the machine grounded more broadly until the fault is resolved.
How a defect drives a tag-out
Most tag-outs begin with a fault. During a pre-start walk-around or in the middle of a job, an operator finds something that means the machine should not carry a person until it is sorted — and the correct response is to stop, lower safely if aloft, and tag the machine before anyone else can use it.
Findings that commonly justify tagging a machine out of service include:
- A safety device that fails its test — a tilt alarm, overload cut-out, interlock or emergency lowering function not behaving correctly.
- Structural concern such as a suspected crack, visible deformation or play at a boom joint that was not there before.
- A hydraulic fault like cylinder drift, where the platform will not reliably hold position.
- Damage or loss of the guardrail, gate, anchor points or any part of the fall-protection system.
- Any condition the operator cannot resolve themselves and that leaves genuine doubt the machine is fit to lift.
Who may remove a tag
The rule that gives the system its teeth is that a tag is not removed casually. An out-of-service tag stays on until the fault behind it has actually been dealt with, and removal is the job of the person with the authority and competence to declare the machine fit again — typically the competent person who repaired or reinspected it, not whoever happens to want the machine next.
A danger tag is stricter still: as a personal tag, it should only be removed by the individual who applied it, or under a controlled process where that is genuinely not possible. Removing someone else's danger tag to get a machine moving is exactly the kind of shortcut the system exists to prevent, because the tag may be the only thing standing between a colleague and a moving boom.
Tagging as part of the wider record
A tag-out does not stand alone. The fault that prompted it should be written into the machine's logbook, and the tag should not come off until the corresponding repair or inspection is recorded and signed. That closes the loop: the machine goes down with a documented reason and comes back up with documented evidence the reason is gone.
Handled this way, tagging becomes part of the same trail as pre-starts, servicing and inspections rather than a separate scrap of card. The logbook shows the fault, the tag-out, the fix and the clearance in sequence, which is precisely what an auditor or a later owner wants to see.
When a tag needs a competent person
The point of a tag is that the machine stays down until someone qualified confirms it is safe, so the temptation to clear a tag under production pressure is the risk to guard against. If a tag is on a machine because of a structural doubt or a safety-system failure, the machine belongs with a competent person before it flies again.
Where a tagged fault is beyond what your own people can resolve — a suspected crack, an unreliable safety circuit, an overdue inspection — the safe path is to have it assessed rather than nursed back into service. To have a tagged-out machine inspected and, where appropriate, repaired and cleared, phone EWP Australia on 0416 689 689.
This guide is general information prepared by EWP Australia and is grounded in publicly available Australian Standards and Safe Work Australia material. It is not a substitute for the current published edition of the relevant standard or for site-specific engineering advice. Always work from the current standard and consult a competent person for your specific equipment and application.