Blog: Foundational WHS

WHS Act 2011 Explained: Australia's Model WHS Framework

Australia's Work Health and Safety Act 2011 is the model legislation behind WHS law in NSW, Queensland, SA, WA, ACT, NT and Tasmania. Victoria still operates under the OHS Act 2004. Understanding which jurisdiction applies and what the Act actually requires is essential for any WHS case analysis.

Author: Karim Ali ChOHSP FAIHS Reading time: 9 min read

Origins of the WHS Act 2011: The Model Laws Project

Before 2011, Australian workplace health and safety law was fragmented across eight separate state and territory regimes with different duty structures, different penalties and different enforcement approaches. Safe Work Australia was established to develop a national model framework that could be adopted by all jurisdictions, creating greater consistency for businesses operating across state borders.

The result was the Model Work Health and Safety Act, first released in 2011 and adopted in various forms by the participating jurisdictions from 2011 onwards. The model Act replaced the previous Occupational Health and Safety legislation in those jurisdictions. Victoria did not adopt the model Act and retained its OHS Act 2004. For a detailed comparison, see WHS vs OHS: what's the difference.

Which States and Territories Adopted the Model Act

  • New South Wales: Work Health and Safety Act 2011 (NSW)
  • Queensland: Work Health and Safety Act 2011 (QLD)
  • South Australia: Work Health and Safety Act 2012 (SA)
  • ACT: Work Health and Safety Act 2011 (ACT)
  • Northern Territory: Work Health and Safety (National Uniform Legislation) Act 2011
  • Tasmania: Work Health and Safety Act 2012 (Tas)
  • Western Australia: Work Health and Safety Act 2020 (WA), effective from March 2022
  • Victoria: Did NOT adopt the model Act. The Occupational Health and Safety Act 2004 (Vic) continues to apply.
Victoria Exception

Victoria's retention of the OHS Act 2004 means that expert analysis in Victorian matters must be conducted against a different legislative framework. The duty structures and regulatory approach differ in meaningful ways. See the Melbourne WHS expert page for more detail.

Key Sections of the WHS Act

Section 18: What is Reasonably Practicable

Section 18 defines the central concept that governs WHS obligations. It sets out five factors to be weighed when assessing what is reasonably practicable: likelihood of the hazard or risk occurring, degree of harm, knowledge, availability of controls, and cost. See reasonably practicable explained for the full analysis.

Section 19: Primary Duty of Care

Section 19 imposes the primary duty of care on PCBUs. The duty extends to workers, other persons at the workplace and, to the extent the PCBU's work influences or directs them, contractors, subcontractors and labour hire workers.

Section 27: Officer Due Diligence

Section 27 imposes a personal duty on officers of PCBUs to exercise due diligence to ensure the PCBU complies with its WHS duties. Officer prosecutions have become increasingly common following serious workplace incidents.

Categories of WHS Offences

The WHS Act creates three categories of offence carrying different penalties. Category 1 is the most serious: reckless conduct exposing a person to risk of death or serious injury, carrying penalties of up to $3 million for corporations. Category 2 covers failure to comply with a health and safety duty, carrying up to $1.5 million for corporations. Category 3 covers failure to comply without exposing a person to risk, carrying up to $500,000 for corporations. Individual penalties are lower but substantial.

WHS Regulations and Codes of Practice

The WHS Act is supported by WHS Regulations that impose specific obligations for particular hazards, including high-risk construction work, confined spaces, hazardous chemicals, plant and equipment, and major hazard facilities. Safe Work Australia also publishes Codes of Practice, which provide guidance on how to comply with the Act and Regulations. Codes of Practice are admissible in proceedings as evidence of what is reasonably practicable.

For detailed analysis of how expert witnesses apply the WHS Act in litigation, see the breach analysis and liability service and the duty holder obligations guide.

Frequently Asked Questions

  • The WHS Act is state and territory law in each jurisdiction that adopted it. There is no single federal WHS Act that applies to all employers. The Commonwealth, through its own legislation, covers Commonwealth employers and Comcare-scheme employees. Each state and territory that adopted the model Act enacted its own version. The Acts are very similar but contain some local modifications.

  • Victoria chose not to adopt the harmonised model WHS Act when it was introduced in 2011, retaining its existing Occupational Health and Safety Act 2004. The Victorian government's position was that its existing OHS legislation already provided adequate protection and that the costs of transition outweighed the benefits of harmonisation. Victoria has since updated its OHS Regulations to align more closely with the model framework, but the primary legislation remains different.

  • Western Australia adopted the Work Health and Safety Act 2020, which came into force on 31 March 2022. Before that date, the Occupational Safety and Health Act 1984 applied. For incidents occurring before March 2022, the OSH Act 1984 governs the analysis. The WHS Act 2020 closely mirrors the national model but includes some WA-specific provisions, particularly for the mining and petroleum industries.