WHS Act duties explained: who must do what?

Under Australia's model work health and safety (WHS) laws, safety duties are shared but not interchangeable. A person conducting a business or undertaking (PCBU) has the primary duty to protect workers and other people affected by the work, so far as is reasonably practicable. Officers must exercise due diligence to ensure the PCBU complies. Workers must take reasonable care and cooperate with reasonable safety instructions and notified procedures. Visitors and other people at a workplace have their own reasonable-care duties. More than one person may owe a duty over the same activity, so hiring a contractor does not simply transfer the host's duty away. These are the model-law roles described by Safe Work Australia.

Jurisdiction matters. The model WHS Act is a framework for laws separately enacted by the Commonwealth, states and territories. It is not one national Act that automatically applies everywhere. All jurisdictions except Victoria have implemented model WHS laws, with local variations. Victoria uses its own Occupational Health and Safety Act 2004 and regulations. Find the actual regulator and current enacted law where the work occurs before making a legal decision. Safe Work Australia explains the model-law and adoption distinction.

This is a role-and-duty guide. It differs from Complys' sole-trader WHS guide, which applies the duties to one-person building businesses, and from the Australian WHS compliance software page, which describes a separate product. The product can help organize records where its current implementation supports that workflow; it does not assume a duty holder's legal decisions.

First identify the duty holders

The same human being can have more than one role. A self-employed tradesperson may be both a PCBU and a worker. An officer is not automatically every supervisor: the role depends on the person's power to make significant decisions or affect the business's financial standing. A worker or officer does not become a PCBU solely by occupying that role. Safe Work Australia's duties overview explains these distinctions.

The PCBU's primary duty

The model-law PCBU duty is broad. It covers workers the PCBU engages or causes to be engaged, and workers whose activities in carrying out work the PCBU influences or directs. It also extends to other people who may be put at risk from the work. The duty is to ensure health and safety so far as is reasonably practicable, not to guarantee that no incident can ever occur. Safe Work Australia's PCBU guidance identifies safe work environments, plant and structures, systems of work, safe handling and storage, facilities, training and supervision, and monitoring among the primary-duty components.

Consider a builder renovating an occupied building. Its own employees are exposed to tools, dust and access hazards. The client's staff or visitors may be exposed to the construction area, dust or changed exits. The builder must address risks its work creates for both groups. The building owner may separately control shared access, fire arrangements or hidden services. These overlapping controls need a coordinated method, not a statement that “the contractor is responsible for safety.”

Reasonably practicable involves what the duty holder knows or should know about the hazard and available controls, the likelihood and possible degree of harm, the availability and suitability of ways to eliminate or minimise the risk, and cost only in the manner the relevant law permits. A low quote or tight programme is not by itself a reason to leave a known serious hazard uncontrolled. Document the decision: the hazard, options considered, chosen measure, responsible person and evidence that it is in place. Check the exact local statutory wording before relying on an exception.

The PCBU may also have additional specific duties, depending on its operations: consultation with workers, risk-management provisions in the regulations, incident notification, training, plant, hazardous chemicals, construction work or other topics. A general duty summary cannot substitute for a register of the regulations that apply to the actual workplace.

Officers: due diligence is active oversight

Under the model WHS Act, an officer must exercise due diligence to ensure the PCBU complies with its WHS duties. Safe Work Australia describes an officer as someone who makes or participates in significant decisions affecting all or a substantial part of the business, or can significantly affect its financial standing. The label on a business card is less useful than the actual decision-making authority. The officer-duty interpretive guidance describes reasonable steps around understanding the work and hazards, resources and processes, receiving and responding to risk information, legal compliance and verification.

For a small trade business, the owner-director might ask: Are the right people trained before a high-risk job? Were defects reported but left open? Is the site using the current SWMS, and did a supervisor check the controls? Has the business funded needed equipment? Are incident reports reaching decision-makers? Merely signing a policy once does not show that a process is operating. Conversely, an officer does not have to personally perform every inspection; due diligence includes making sure the right processes exist, are resourced and are verified.

Record the source of leadership information, decisions and follow-up. For example, a monthly report can show overdue serious corrective actions and who is clearing them; a site visit can test whether the report reflects reality. A dashboard is useful only if it leads to action.

Workers and other people

Workers must take reasonable care for their own health and safety and that of other people affected by their acts or omissions. They must comply, so far as reasonably able, with reasonable instructions given to allow the PCBU to comply with WHS law and cooperate with reasonable WHS policies or procedures that have been notified to them. Safe Work Australia's role summary includes employees, contractors, subcontractors, labour-hire workers, apprentices, work-experience students and volunteers within the model worker concept when they carry out work for a PCBU.

That duty matters in practical situations. A worker should use a required machine guard, follow an isolation process, warn others of a new hazard and report a defective control. A worker duty does not erase the PCBU's duty to provide safe plant, instruction or a workable system. If the issued method cannot be followed safely, the supervisor and workers need to resolve the problem rather than treat a worker signature as a transfer of responsibility.

Visitors, customers and other persons at a workplace must take reasonable care for themselves and others and follow reasonable safety instructions given under the model law. The PCBU still needs to manage risks to them that arise from its work. Explain access restrictions, traffic routes and emergencies in a way visitors can use.

Why duties overlap on contractor jobs

Suppose a roofing subcontractor works above a warehouse's active loading area. The roofer controls its workers, tools, work method and fall-prevention arrangement. The warehouse controls normal vehicle movements, pedestrian access and some building information. A head contractor may coordinate the project and common work areas. More than one PCBU may therefore owe duties in relation to the same exposure. The model laws require PCBUs with overlapping duties to consult, cooperate and coordinate to the extent reasonably practicable. See Safe Work Australia's duty principles and the contractor onboarding guide for a task-specific application.

Before work starts, agree who cordons the loading area, who verifies the exclusion zone, how roof access and weather decisions are made, and how the warehouse learns that the zone can reopen. A subcontract agreement may allocate tasks and evidence, but it does not remove a statutory duty. If one party's control fails, the other party should not assume a document on file means the exposure has disappeared.

A simple duty-mapping worksheet

Fill this with actual people and site conditions. “Both parties responsible” is incomplete if neither knows who puts a barrier in place. Revisit the map when scope, personnel or layout changes.

How to put the duties into practice

1. Find the actual law. Identify jurisdiction, regulator, industry and any local variation. Safe Work Australia's model-law page is an overview; the enacted state, territory or Commonwealth law controls.
2. Identify every role. List the PCBU for each activity, officers with oversight, workers, site controller and other affected people. Mark overlaps.
3. Identify hazards and decisions. Walk the job with workers. Record who could be harmed, control options and any standard-specific duty. Decide who has authority to stop or change work.
4. Resource and implement controls. Provide plant, people, time, training and supervision. A form or SWMS helps only if the controls are actually used.
5. Consult and coordinate. Ask workers about practical constraints; exchange hazard and control information with other PCBUs. Assign each interface and check that the other party understands it.
6. Verify and improve. Check critical controls at the workface, investigate incidents and near misses, track corrective actions and escalate unresolved issues to officers. Revisit duties when new equipment, contracts or work methods appear.

For a high-risk construction activity, the separate SWMS guide explains the task statement. An SWMS is one way to describe a method; it is not the full extent of an officer's, PCBU's or worker's obligations.

Victoria and multi-state work

Do not describe the model WHS Act as Victoria's law. Victoria retains the Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017. WorkSafe Victoria's employee guide explains employers' duty to provide and maintain a safe working environment and the Victorian consultation duty. The roles and language differ from the model PCBU/officer provisions, even where practical safety goals overlap. A company operating in both Victoria and an adopting jurisdiction should map duties separately rather than attach “Victoria” to a generic model-law document.

For any state or territory, model-law amendments do not automatically amend the local Act or regulations. Safe Work Australia explicitly warns that jurisdictions enact and vary the model laws. Before release or legal training, check the current regulator, law and any industry-specific rules where the work is done.

Where records and Complys fit

Good records show which hazard was found, who decided the control, whether workers were consulted, who owns the action and whether the control was checked. They support operational learning and evidence; a document cannot transfer a duty or certify compliance. The Complys Australian WHS compliance software page is the natural product destination for an employer seeking one place to organize applicable records. The exact currently available features and commercial offer must be verified against the implementation before publication. Do not state that Complys legally determines duties, certifies compliance or submits notifications to regulators.

Questions about WHS Act duties

Can an employer pass its WHS duty to a subcontractor?

The contract can allocate work and evidence, but duties under the model law can overlap and cannot simply be transferred away. The host and subcontractor must identify what each controls and coordinate on shared risks. Check the enacted jurisdictional law and the specific activity.

Is a director automatically personally liable for every incident?

No blanket conclusion follows from a job title or an incident. Under the model law, an officer has a due-diligence duty; whether someone is an officer and whether they discharged that duty depend on the facts and the applicable law. Obtain jurisdiction-specific legal advice on an actual event.

Does a worker's signature on a SWMS remove the PCBU's duty?

No. A sign-on may evidence that a worker was briefed, but the PCBU still has to manage the work and verify controls. The worker still has their own reasonable-care and cooperation duties.

Does this guide apply in Victoria?

The practical idea of identifying and controlling hazards remains relevant, but the model WHS Act role labels and sections are not Victoria's law. Use WorkSafe Victoria's OHS Act and regulations for Victorian legal obligations.

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Writer-side source/claim register — researched 5 October 2026

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