A Level Playing Field - The End of Reverse Onus
Part 1 of 14 Workplace Health & Safety Update
Authors: Robin Young, Partner and Nick Read, Solicitor
2 June 2011
One of most important changes that has been made is the abolition of the current law requiring businesses to prove their innocence.
What is the reverse onus?
Under current OHS law WorkCover must prove the precise nature of risk to health and safety and the measures that should have been taken to avoid the risk. The only way for a business to defend a prosecution is to show the that the measures WorkCover asserts should have been taken were not “reasonably practicable.” Therefore, unlike typical criminal prosecutions where the burden of proof (or onus) is on the prosecutor to prove each element the offence beyond reasonable doubt, the onus shifts to the business to establish a defence.
What are the changes?
Under the WHS Bill, the burden of proof remains at all times with WorkCover. Along with proving the essential elements of an offence, WorkCover will have to prove that the measures it asserts should have been taken reasonably practicable.
“Reasonably practicable” is defined as meaning that which was reasonably able to be done in relation to ensuring health and safety, including the following:
- The likelihood of the risk occurring.
- The degree of harm that might result from the risk.
- What the person concerned knows, or ought reasonably know, about the risk and the ways of eliminating it.
- The availability or suitability of ways to eliminate or minimise the risk.
- Although of less importance than the above, the costs associated with ways of eliminating or minimising the risk can be taken into account.
How will the changes come into force?
The new provisions will apply to all incidents that occur after the date of assent (27 May 2011). The provisions will not apply to incidents that have already taken place and are currently being investigated or which are already before the Court.
Like the High Court’s decision in Kirk before it, the end of reverse onus will substantially change the OHS landscape. Prior to commencing prosecutions WorkCover will be faced with an additional consideration, that being, whether what the measures it asserts should have been taken to avoid a risk to health and safety were reasonably practicable, and if so, why?
In practice, where a risk is obvious, it will usually follow that the measures to be taken to avoid it are reasonably practicable. For example, the risk of working at heights without fall protection is obvious. The ways of eliminating the risk (e.g. using harnesses, erecting fencing or handrails) are known to all in the construction industry. It will therefore be straightforward for WorkCover to show that the measures which should have been taken to avoid the risk were reasonable practicable.
However, in cases where the likelihood of the risk occurring is low, proving a measure was reasonably practicable may require expert opinion. The additional burden and costs associated with instructing experts in proving low probability offences is likely to drive down the numbers of prosecutions.
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 See Kirk v Industrial Relations Commissionof New South Wales  HCA 1.
 s28 Occupational Health & Safety Act 2000 (NSW).