Consequence-based decision making in a risk-based regulated regime

Abstract

Fifteen contractor staff died in 2005 Texas City accident when a "350 feet" BP company rule was breached. Was the mandated rule adequate or was it a rule overruled by a bias on-site risk-based decision? Is it reasonable for such ineffective rules to override a potentially rational risk-based decision or can a converse overtake option still be acceptable? Whist a risk-based approach admits that risk is inevitable, a consequence-based approach disregards the likelihood of an event and thus rejects the concept of risk, known as a product of consequence and likelihood. Consequence-based decisions are mainly made to eliminate the risk rather than reducing it to an acceptable level. Should senior management in control of major accident/ high hazard facilities adopt any safety strategies based on consequence? How would such strategies differ under a risk based-model using high consequence, low frequency events and demonstrating that the risk is reduced to a level that is as low as reasonably practicable (ALARP) by a reasonable list of preventative and/ or mitigative controls, e.g. as regulated in the Safety Case regime and based on the concept of "duty of care"? A set of discussions from our research are outlined in this paper, which include key findings and comparisons between consequence estimations using the quantity distance rule and risk-based assessments in defining safety strategies in the manufacturing and storage of explosives in Australia