Lockout-tagout in Australia is not one law. It is two codes with one rule: test for dead before you touch.

Energised work is prohibited, and convenience is not an exception

The electrical code's centre of gravity is WHS Regulation 154: a PCBU must ensure electrical work is not carried out on energised equipment. Regulation 157 allows exactly four exceptions: it is necessary in the interests of health and safety (life-support equipment that must stay running is the code's example); it is necessary for the work to be done properly; it is necessary for testing under regulation 155; or there is no reasonable alternative. The code then closes the loophole most workplaces actually use: work must not be done energised "for the reason of it being merely more convenient", and only in extremely rare circumstances could a duty holder justify avoiding a short supply interruption. Electrical work, energised or not, must only be carried out by appropriately licensed or registered electrical workers under each jurisdiction's licensing law; that part never harmonised nationally.

Before any electrical work starts, regulation 155 requires the equipment to be tested by a competent person to determine whether it is energised, with every exposed part treated as energised until isolated and proven otherwise. The code compresses this into the principle it sets in capitals: "TEST FOR 'DEAD' BEFORE YOU TOUCH", and specifies the full discipline behind it: test the tester on a known live source, test the equipment, then retest the tester to confirm it still works. Testing for dead must happen each time work is carried out, including on return after leaving the work area, and a panel voltmeter is not an acceptable sole method.

The isolation sequence, and why a tag is not a lock

To keep equipment dead, the code sets a standard isolation sequence: consult, identify the circuits, disconnect from every source (including standby generators and photovoltaic systems), secure the isolation by locking the isolating switches, tag the switching points, test, and retest as necessary. Regulation 156 makes the outcome a duty in itself: de-energised equipment must not be able to be inadvertently re-energised while work is carried out. The point of isolation should be under the control of the person doing the work, and where several people work on the same installation, each applies a personal lock. On tags, the code is unambiguous: "A tag does not, by itself, perform the isolation function." Danger tags warn; only a lock isolates.

Electricity is only one energy source, and this is where the November 2024 plant code takes over. Its isolating-energy-sources section names the rest: battery and capacitor banks, solar panels, fuels, heat, steam, fluids and gases under pressure, compressed springs, gravity, radiation. Its lock-out process runs eight steps: shut down; identify all energy sources and hazards; identify all isolation points; isolate all energy sources; control or de-energise all stored energy; lock out all isolation points; tag machinery controls; and test by trying to reactivate the plant without exposing anyone to risk. The code adds the disciplines that make a lock-out system auditable: each worker holds their own lock, tag and key; no duplicate keys except an emergency master held securely; tags and locks are removed only by the person who applied them, or by a supervisor after consulting the tag's signatory. A failed reactivation test, it warns, proves mains isolation but not that stored energy such as hydraulic pressure or a suspended weight has dissipated. Whether these steps are actually followed on the floor is precisely the kind of implementation question a WHS audit scores, as most of the national audit tool's criteria sit under implementation rather than documentation.

The standing duties: test and tag, RCDs, and the records

Inspection and testing intervals the electrical code states as the general rule for plug-in equipment in higher risk operating environments (WHS reg 150; the code defers detail to AS/NZS 3760, which is paywalled and not reproduced here). Lower-risk environments such as offices still warrant less frequent inspection and testing.

Two further duties round out the set. Under regulation 164, plug-in equipment used in hostile operating environments, or moved frequently or between locations in ways likely to damage it, must be protected by a residual current device; where an RCD is required on a socket outlet up to 20 amps, its tripping current must not exceed 30 milliamps. Under regulation 165, RCDs must be tested regularly by a competent person, with records kept until the next test. The equipment-testing records under regulation 150 carry the same until-next-tested rule and must name the tester, the date, the outcome and the next due date; a tag on the equipment can be the record. These are exactly the documents an inspector or a court reaches for after a shock incident, and the cheapest ones to get right in advance.

One more thing worth knowing about this code: the current edition is dated October 2018 and has not been revised since, which now makes it one of the older instruments on Safe Work Australia's model-laws shelf, where recent years have brought new or updated codes for fatigue, plant, construction and the work environment. Nothing in it has lapsed, and codes remain admissible in court as evidence of what is known about a hazard and what is reasonably practicable; but a duty holder should expect any future revision to tighten rather than loosen, and the 2018 numbers above are the floor in the meantime.