ALARP & the WHS Legislation
The recent surge in the ALARP debate amongst engineers has prompted the R2A partners to reconsider how it was that ALARP was developed at all and how it has caused so much controversy, at least in Australia. Our recent blogs Risk Paradigm Shift Takes a Generation and Is There a Difference between ALARP & SFAIRP? The Debate Continues covered much of this, but since the debate continues we felt it was worth a further comment.
The ALARP debate seems to have arisen from Sir Frank Layfield’s (a lawyer) Sizewell B Inquiry of 1987. Whilst he gave approval for the nuclear power station station to proceed, there were a number of matters that were unresolved including, for example, an understanding of the level of danger posed by anticipated radiation levels. Sir Frank recommended that this matter be investigated further.
Practically, the task was passed on to the then newly established (1975) UK Health and Safety Executive (HSE). Whilst Sir Frank was assisted by a large number of engineers, the UKHSE’s document, The Tolerability of Risk from Nuclear Power Stations (1988) appears to have been prepared mostly by scientists. It is a careful document. The so called dagger diagram which is used to describe the ALARP approach does not have any risk numbers shown on it. These are summarised in the appendix of the document.
Never-the-less, the use of numbers was popularly seized upon. That is, the risk numbers in the Appendix was applied to the diagram as shown above (from a summary by the International Atomic Energy Agency on the Tolerability of Risk the ALARP Philosophy.
This was all very unfortunate as it is a proposition the courts (at least Australian courts) were never able to accept. As Sir Harry Gibbs (Chief Justice of the Australian High Court) put it in 1982:
Where it is possible to guard against a foreseeable risk, which, though perhaps not great, nevertheless cannot be called remote or fanciful, by adopting a means, which involves little difficulty or expense, the failure to adopt such means will in general be negligent
(Turner v. South Australia (1982) 42 ALR 669).
That is, it does not matter how rare an event is, if the consequences are critical and more could have reasonably be done to prevent or manage the outcomes, then the courts, post-event, will consider this failure to be negligent.
Since this common law understanding is that which was put into the OHS/WHS legislation, the ALARP approach using target levels of risk became, by statute, quite unsupportable.
From the R2A perspective, this became clear when the OHS Act in Victoria (2004) commenced as the enabling legislation for major hazard facility (MHF) regulators. This result required that R2A change from being risk engineers to due diligence engineers. It also precluded R2A from providing MHF advice as long as relevant MHF regulators continued to use target-level-of-risk arguments rather than criticality driven safety-in-design arguments.
Happily, this changed in Victoria where the MHF regulator in 2022 moved to the Gibbs position. That is, the credible worst case outcomes (the science - which remains arguable for complex hazard scenarios) is described and then the possible control options considered (a design exercise), as shown in the diagram below.
From a pre-event perspective, the more scientists know, the better engineers can do, although there is a functional overlap between the two. Post-event, the courts are actually completing a retrospective design review to test if any design options were overlooked or poorly implemented from what is an awful, but now known, outcome.
This is entirely consistent with the thinking of David Howarth, the Professor of Law and Public Policy from Cambridge University (whom R2A sponsored to Melbourne in 2017) in his book Law as Engineering. The law is chiefly a design process, and the lawyers are looking to the engineers for inspiration (Watch this short presentation by David Howarth).
Based on this, there seems to be a general intellectual alignment emerging amongst lawyers, engineers and scientists on how this all should be done.
If you’d like to discuss further how our work helps ensure governance outcomes that meet Australian WHS/OHS legislation that all reasonably practicable precautions are in place for high consequence, low likelihood events, head to our contact page.