Australia: Principles of OSH liability in WA where principals engage specialist contractors

Between 2008 and 2012, the Supreme Court of Western Australia handed down a series of decisions, arising from two incidents relating to the OSH liability of principals who engage specialist or expert contractors.1 Whilst not purporting to change the applicable legal principles, the Courts exhibited a tendency towards a principal being entitled to satisfy their OSH responsibilities by delegating specialised tasks to contractors. In 2012, very shortly (7 days) after the last of these judgments, the High Court handed down a judgment which, in a different matter, appeared to support the Supreme Court's position.2

Generally speaking, the Courts were prepared to accept that a principal which engages a contractor to do specialised work may satisfy its OSH obligations by the act of engaging that contractor.

This article will set out, using the words of the Court as closely as possible, the principles affirmed in the cases referred to above, as follows:

  1. The duty imposed by s19(1) is a higher duty that is imposed at common law, but it is not an absolute duty.
  2. The words "reasonably practicable" are ordinary words, bearing their ordinary meaning and simply call for the making of a value judgment in light of all the facts. Hindsight may mislead.3
  3. The Act does not require employers to ensure that accidents never happen. It requires them to take such steps as are practicable to provide and maintain a safe working environment. The courts will best assist the attainment of this end by looking at the facts of each case as practical people would look at them: not with the benefit of hindsight, nor with the Wisdom of Solomon, but nevertheless remembering that one of the chief responsibilities of all employers is the safety of those who work for them.4
  4. The words "reasonably practicable" indicate that the duty does not require an employer to take every possible step that could be taken. The steps that are to be taken in performance of the duty are those that are reasonably practicable for the employer to take to achieve the identified end of providing and maintaining a safe working environment. Bare demonstration that a step could have been taken and that, if taken, it might have had some effect on the safety of a working environment does not, without more, demonstrate that an employer has broken the duty.5
  5. It is always possible to imagine a further step, an additional check or a second opinion that could be obtained, particularly with the benefit of hindsight. The question is not whether something else could conceivably be done, but whether it was reasonably practicable to expect principals in the position of the respondents to do more.6
  6. The measures which are required to be taken to avoid exposing those at a workplace to injury or harm will only be practicable where there exists a state of knowledge about the risk of injury or harm in question occurring and a means of removing or mitigating it. It could hardly be said to be practicable for a person to make measures to ensure the safety of those at a workplace in respect of a risk which is unknown.7
  7. To secure a conviction, the prosecutor must prove either that the defendant actually knew of the risk of injury or harm to health occurring or that a reasonable person in the position of the defendant would have appreciated or foreseen the risk of the injury or harm to health occurring.8
  8. The legislation did not intend to impose upon a principal who has engaged a specialist contractor (who is not ordinarily susceptible to direction to how to perform its work) a general obligation to supervise the manner in which the contractor (having an expertise that the principal lacks) goes about the performance of the work entrusted to it.9
  9. If the obligation to provide a safe workplace requires an employer to call upon expertise that it lacks, then it should do so. However, if the employer had relied upon a specialist contractor to perform a task which demonstrably fell within its area of expertise and outside that of the employer, and if the task reasonably appears to the employer (who has such knowledge of the matters specified in the definition as might be expected to be had by employers of its kind) to have been carefully and safely performed by the specialist contractor, it would ordinarily be difficult to conclude that the employer had breached the duty put upon it by the Act.10
  10. A person is not absolved of responsibility for their workers merely because someone else also has a duty in respect of them. Accordingly, it would be no answer to a charge to suggest that another responsible entity has failed in its duty. The question is always whether the person who has been charged with a contravention has failed to do all that it is reasonably practicable for them to do to ensure that their workers are protected from hazards.11
  11. In some cases, the duty to, so far as is practicable, maintain a safe workplace may involve a consideration of matters which are beyond the employer's own area of expertise. Although the employer's duty remains unaltered, the employer's lack of direct control over such matters may affect its knowledge and, in consequence, the question of what was "reasonably practicable" in the circumstances.12
  12. It is unlikely to be enough for a person to merely assume that someone else will attend to safety requirements, but if such an assumption is based upon inquiries made, assurances given, a reasonable belief as to the skills of those responsible for construction and a reasonable belief that regulatory approval has been obtained for the buildings, it may be well-founded.13
  13. Merely 'thinking' that work has been done without any factual foundation for forming that view is not sufficient.14
  14. Section 19(4) [which deems the principal is deemed to be the employer with respect to matters "over which he has control of"] is directed to matters over which the principal has control and is concerned with actual control over a particular matter affecting safety, rather than general responsibility for, or control over, the workplace.15
  15. There is no absolute obligation on a person to take measures to ensure safety in the workplace in respect of risks of which that person was not, and could not reasonably have been expected to be, aware.16
  16. When considering the 'state of knowledge' about the severity of any potential injury, the risk of it occurring and the means of removing or mitigating it, the words 'state of knowledge' encompasses not only what is known concerning those matters, but also who might ordinarily be expected to have that knowledge. Consequently, when considering whether it was reasonably practicable for a deemed employed to have avoided a particular hazard, it would be a relevant consideration that the expert knowledge required to avoid the hazard fell within the province of the specialist contractor which had been engaged to do the work that gave rise to the hazard and outside that of the deemed employer.17

Whilst these cases demonstrate that, in certain circumstances, a principal can satisfy its OSH duties by engaging a contractor, the principal must always remember that:

  • it is not, in any circumstances, able to contract out of its OSH duties;
  • it must still ensure that the contractor has the specialised knowledge it purports to have, that it has appropriate safety systems in place and that, so far as it is possible to test, it is complying with those systems;
  • the contractor is usually limited by the instructions it is given by the principal – if those instructions are incorrect or incomplete, the 'protection' provided by engaging an expert contractor is unlikely to be sufficient; and
  • the difference in expertise between the principal and contractor is crucial – the greater the difference, the less "reasonably practicable" it is likely to be for the principal to independently identify hazards in the course of the contractor's work.


1Reilly v Devcon Australia Pty Ltd [2008] WASCA 84; Tobiassen v Reilly [2009] WASCA 26; Laing O'Rourke (BMC) Pty Ltd v Kirwin [2011] WASCA 117; Kirwin v The Pilbara Infrastructure Pty Ltd [2012] WASC 99

2 Baiada Poultry Pty Ltd v The Queen [2012] HCA 14

3 Laing O'Rourke at [31]

4 Laing O'Rourke at [31], quoting Holmes v RE Spence & Co Pty Ltd (1992) 5 VIR 119 at 123-124

5 Baiada at [15]

6 Kirwin at [147]

7 Tobiassen at [58]

8 Reilly at [60]

9 Reilly at [35]

10 Reilly at [64], Tobiassen at [54], [62]

11 Kirwin at [93]

12 Laing O'Rourke at [35]

13 Kirwin at [108]

14 Kirwin at [167]

15 Reilly at [47]

16 Tobiassen at [59]

17 Reilly at [60]

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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