Section 19: WHS Primary Duty of Care

Regulatory citation: Work Health and Safety Act 2011 (model law), Section 19

What Is the WHS Primary Duty of Care?

Section 19 of the Work Health and Safety Act 2011, the model legislation adopted (with minor jurisdictional variations) across most Australian states and territories, establishes the primary duty of care in Australian workplace safety law. It requires a "person conducting a business or undertaking" (PCBU) to ensure, so far as is reasonably practicable, the health and safety of workers and other people who may be affected by the conduct of the business or undertaking.

Why the Primary Duty of Care Is Central to WHS Law

Much like OSHA's General Duty Clause and the UK's Section 2 duty, Australia's primary duty of care establishes a broad, foundational obligation applying across virtually all business activities. More specific WHS regulations and codes of practice build upon this primary duty, adding detail for particular hazards, industries, or activities.

Understanding "PCBU" and Why It Matters

The term "person conducting a business or undertaking" (PCBU) is deliberately broader than "employer." It captures a wide range of business structures, including companies, sole traders, partnerships, and, in many cases, principal contractors overseeing subcontracted work, reflecting the reality of modern, often layered, business and contracting relationships. This means multiple parties can simultaneously hold WHS duties for the same workplace or activity, each responsible for the matters within their control or influence.

Core Obligations Under Section 19

1. Duty to Workers

A PCBU must ensure, so far as is reasonably practicable, the health and safety of workers engaged, or caused to be engaged, by the PCBU, and workers whose activities are influenced or directed by the PCBU, including contractors and labor hire workers, not just direct employees.

2. Duty to Other Persons

A PCBU must also ensure, so far as is reasonably practicable, that the health and safety of other persons is not put at risk by work carried out as part of the business or undertaking, which extends the duty to visitors, customers, and members of the public who may be affected.

3. Provision of Safe Plant and Structures

The duty specifically includes ensuring, so far as reasonably practicable, safe plant and structures, safe systems of work, and safe use, handling, and storage of substances.

4. Adequate Facilities

PCBUs must ensure adequate facilities are available for the welfare of workers, including access to those facilities.

5. Information, Training, Instruction, and Supervision

Workers must be provided with the information, training, instruction, or supervision necessary to protect them from risks to their health and safety arising from work.

6. Health Monitoring and Conditions

The health of workers and the conditions at the workplace must be monitored to prevent illness or injury arising from the conduct of the business or undertaking.

What "Reasonably Practicable" Means Under WHS Law

Similar to the UK's standard, "reasonably practicable" under Australian WHS law requires weighing factors including the likelihood of the hazard or risk occurring, the degree of harm that might result, what the PCBU knows or ought reasonably to know about the hazard and ways to eliminate or minimize it, the availability and suitability of ways to eliminate or minimize the risk, and, after assessing the extent of the risk and available control measures, the cost associated with those measures, including whether the cost is grossly disproportionate to the risk.

Common Compliance Approaches

Applying the Hierarchy of Controls

WHS regulations formally embed a hierarchy of controls, requiring PCBUs to first attempt to eliminate risks, and where that's not reasonably practicable, to minimize risks through substitution, isolation, engineering controls, administrative controls, and PPE, in that order of preference.

Consulting With Workers

WHS law includes specific consultation requirements, meaning PCBUs must consult with workers on matters that directly affect their health and safety, which supports both compliance and practical, on-the-ground risk identification.

Managing Multi-PCBU Sites

On sites involving multiple PCBUs, such as construction projects with several contractors, clear documentation of which party is responsible for specific risks helps demonstrate that each PCBU has met their own primary duty of care obligations.

Example: Primary Duty of Care in Practice

A construction company (the principal contractor PCBU) engages several subcontractors for a commercial build. Under Section 19, the principal contractor must ensure, so far as reasonably practicable, the health and safety of not just its own direct workers, but also subcontracted workers whose activities it influences or directs, along with members of the public who may pass near the site. The principal contractor identifies a fall hazard associated with a specific stage of the build, applies the hierarchy of controls by first considering whether the task can be redesigned to eliminate work at height, and where that's not feasible, implements engineering controls (guardrails) supplemented by fall arrest systems, consulting with the affected subcontracted workers on the practical implementation of these controls before work begins.

Frequently Asked Questions

What is the primary duty of care under Australian WHS law?

The primary duty of care, established under Section 19 of the Work Health and Safety Act 2011, requires a person conducting a business or undertaking (PCBU) to ensure, so far as is reasonably practicable, the health and safety of workers engaged by the business and other persons who may be put at risk by the business's activities. This duty covers a wide range of specific obligations, including providing safe plant, structures, and systems of work, ensuring safe use and storage of substances, providing adequate welfare facilities, delivering necessary information, training, and supervision, and monitoring worker health and workplace conditions to prevent illness or injury. Because the duty extends beyond direct employees to include contractors, labor hire workers, and even members of the public affected by the business's activities, it's considerably broader in scope than a traditional employer-employee safety obligation, reflecting the diverse and often layered nature of modern work arrangements.

Who counts as a PCBU under WHS law?

A PCBU, or "person conducting a business or undertaking," is a deliberately broad term used under Australian WHS law to capture the wide range of structures through which work is actually organized in modern business. This includes traditional employers, but also sole traders, partnerships, companies, and principal contractors who oversee work performed by subcontractors, even where those subcontractors aren't directly employed by the principal contractor. Because of this broad definition, multiple PCBUs can simultaneously hold primary duty of care obligations for the same workplace, project, or activity, each responsible for the specific matters within their control or influence. This is particularly relevant on complex sites like construction projects, where a principal contractor, individual subcontracting businesses, and equipment suppliers might all hold overlapping but distinct WHS duties relating to the same overall project, requiring clear understanding of who is responsible for which specific risks.

What does "reasonably practicable" mean under WHS law?

Under Australian WHS law, "reasonably practicable" requires a PCBU to weigh several specific factors when determining what steps are required to manage a health and safety risk. These factors include the likelihood of the hazard or risk actually occurring, the degree of harm that could result if it did, what the PCBU knows or reasonably ought to know about the hazard and the ways of eliminating or minimizing it, the availability and suitability of ways to eliminate or minimize the risk, and, after weighing the extent of the risk against available control measures, the cost associated with those measures, including whether that cost is grossly disproportionate to the risk involved. This framework is similar in structure to the "reasonably practicable" standard used under UK health and safety law, requiring a genuine, proportionate assessment rather than either an absolute duty to eliminate all risk regardless of cost, or a minimal duty limited to only the most convenient or inexpensive measures.

How does the primary duty of care apply when multiple businesses work on the same site?

When multiple PCBUs are involved in the same workplace or project, such as a principal contractor and several subcontractors on a construction site, each PCBU holds their own primary duty of care obligation under Section 19, generally scoped to the matters within their control or influence. This means a principal contractor overseeing a project typically holds broader responsibility given their overall influence over site conditions and coordination between different work activities, while individual subcontractors hold primary responsibility for the specific hazards and work practices within their own scope of work. WHS law also includes specific requirements for these multiple duty holders to consult, cooperate, and coordinate activities with each other to the extent each is able to influence the matter, recognizing that safety on a multi-party site depends on effective coordination rather than each party operating in isolation. Clear documentation of which party is responsible for specific risks, along with genuine, ongoing coordination between the involved PCBUs, both supports practical safety outcomes and helps demonstrate that each party has met their own distinct primary duty of care obligations under the Act.