What PCBU, “reasonably practicable” and the other WHS terms mean, in the Act's own words

Which Act this is, and whether it is yours

The text quoted here is the Commonwealth Work Health and Safety Act 2011, Compilation No. 16, in force from 1 July 2024, which is the version the federal register serves as current. It covers Commonwealth workplaces directly. It matters well beyond them because it follows the national model, and Safe Work Australia says The model laws have been implemented in all jurisdictions except Victoria. Each other state and territory has its own Act built on that model, so outside Victoria these are the terms your own Act is built around. A jurisdiction's Act can still differ in wording, numbering and penalties, so anything that turns on exact words should be checked in your own Act. For who owes which duty and how the layers fit together, the plain-English version is our map of Australia's safety laws; this page is the dictionary behind it.

Person conducting a business or undertaking (PCBU), section 5

The Act does not define the phrase in one sentence. It says what counts: a person conducts a business or undertaking : (a) whether the person conducts the business or undertaking alone or with others; and (b) whether or not the business or undertaking is conducted for profit or gain. And what does not: A person does not conduct a business or undertaking to the extent that the person is engaged solely as a worker in, or as an officer of, that business or undertaking.

Worth knowing beyond the definition: the duty holder is not “the employer”. Not-for-profit work is caught by paragraph (b), and section 5 also reads a partnership's duty as falling on each partner in the partnership, not on the firm as a single thing. Section 5 also carves out exemptions, which our explainer on what a PCBU is walks through.

Worker, section 7

A person is a worker if the person carries out work in any capacity for a person conducting a business or undertaking, and the Act then lists, among others, employees, contractors and subcontractors, labour hire employees, outworkers, apprentices and trainees, students on work experience, and volunteers.

Worth knowing: “in any capacity” is the part that does the work. A contractor's own employee and a labour hire worker are both your workers for safety purposes even though neither is on your payroll, which is the ground covered in our piece on labour hire and the gig economy.

Workplace, section 8

A workplace is a place where work is carried out for a business or undertaking and includes any place where a worker goes, or is likely to be, while at work. Section 8 adds that a place includes a vehicle, vessel, aircraft or other mobile structure.

Worth knowing: the definition follows the worker, not the building. A work vehicle is named outright, and a client's premises can be a workplace while you work there.

Reasonably practicable, section 18

The phrase that qualifies almost every duty in the Act means that which is, or was at a particular time, reasonably able to be done in relation to ensuring health and safety, taking into account and weighing up all relevant matters. The Act then names five: the likelihood of the hazard or risk; the degree of harm; what the person knows or ought reasonably to know about the risk and ways of dealing with it; the availability and suitability of those ways; and, only after all of that, the cost.

Worth knowing: cost comes last, and the test it sets is strict. The Act asks whether the cost is grossly disproportionate to the risk. A control that is merely expensive is not ruled out by that test; one whose cost is grossly out of proportion to the risk can be. And “or was at a particular time” means the question is judged at the moment of the incident, using what was known or knowable then.

Primary duty of care, section 19

A person conducting a business or undertaking must ensure, so far as is reasonably practicable, the health and safety of: (a) workers engaged, or caused to be engaged by the person; and (b) workers whose activities in carrying out work are influenced or directed by the person; while the workers are at work in the business or undertaking.

Worth knowing: paragraph (b) does not depend on who employs the worker. A business that influences or directs a subcontractor's crew can owe them this duty without employing any of them.

Officer, section 4, and the duty of due diligence, section 27

For a company, the Act does not write its own definition. An officer is an officer of the entity within the meaning of section 9 of the Corporations Act 2001, and the definition expressly does not include if the entity is a local authority, an elected member of the local authority acting in that capacity. Where the Act does write its own, for Commonwealth agencies, an officer is a person who makes, or participates in making, decisions that affect the whole, or a substantial part, of the business or undertaking of the agency.

The duty is in section 27: an officer must exercise due diligence to ensure that the person conducting the business or undertaking complies with that duty or obligation. Section 27(5) says due diligence includes taking reasonable steps to keep up-to-date knowledge of WHS matters; to understand the operations and their hazards and risks; to ensure the business has, and uses, the resources and processes to eliminate or minimise risk; to ensure it has processes for receiving and responding to information about incidents, hazards and risks; to ensure it has, and implements, processes for complying with its duties; and to verify the provision and use of the resources and processes.

Worth knowing: the last step is verification. Approving resources and processes is not the whole of it: the Act asks the officer to check they are provided and used.

Notifiable incident, section 35

notifiable incident means: (a) the death of a person; or (b) a serious injury or illness of a person; or (c) a dangerous incident.

Worth knowing: two of the three are themselves defined terms, below, so whether you must notify the regulator turns on those two definitions rather than on how bad an injury looks. How fast you must notify, state by state, is in our notification deadlines table.

Serious injury or illness, section 36

An injury or illness requiring (a) immediate treatment as an in-patient in a hospital, or immediate treatment for one of eight listed injuries (amputation, a serious head injury, a serious eye injury, a serious burn, degloving or scalping, a spinal injury, the loss of a bodily function, and serious lacerations), or (c) medical treatment within 48 hours of exposure to a substance.

Worth knowing: it is a list, not a severity scale. An injury that is painful and keeps someone off work for weeks, but needs none of the listed treatments, is not a serious injury under this section, and an exposure that needs medical treatment within 48 hours is one even if the person feels fine.

Dangerous incident, section 37

an incident in relation to a workplace that exposes a worker or any other person to a serious risk to a person's health or safety emanating from an immediate or imminent exposure to one of a list of events, including an uncontrolled escape of a substance, gas, steam or pressurised substance; an uncontrolled implosion, explosion or fire; electric shock; the fall or release from a height of any plant, substance or thing; and the collapse of a structure or of an excavation.

Worth knowing: nobody has to be hurt. Because a dangerous incident is itself a notifiable incident under section 35, a near miss of one of the listed kinds is notifiable in its own right.

Industrial manslaughter, section 30A

The offence is committed by a PCBU or an officer who has a health and safety duty and intentionally engages in conduct that breaches the duty and causes the death of an individual, where the person was reckless, or negligent, as to whether the conduct would cause the death of an individual. In the Commonwealth Act the maximum penalty is 25 years' imprisonment for an individual and $18,000,000 for a body corporate, and the Act notes There is no limitation period for bringing proceedings for an offence against this subsection.

Worth knowing: these are the Commonwealth Act's figures. Each jurisdiction's own Act sets its own offence and penalty, so they are not necessarily your state's figures. We compare them jurisdiction by jurisdiction in our industrial manslaughter guide.

The term the Act does not use: psychosocial

The word “psychosocial” does not appear anywhere in the Act's text. We searched the whole of Compilation No. 16 for it and found no instance. Yet Safe Work Australia states that Under the model WHS laws, a person conducting a business or undertaking (PCBU) must manage the risk of psychosocial hazards in the workplace.

Worth knowing: both are true, and together they tell you where to look. The general duties above already reach mental health, because section 4 says health means physical and psychological health. The specific requirements for psychosocial hazards are not in the Act, so a reader looking for them there will not find them. Start from Safe Work Australia's psychosocial hazards page, linked below, rather than from the Act.

Spotted an error, or has the Act changed since we read it? Tell us and we will check it against the Act and log the outcome.