The ongoing challenge of demonstrating alarp in COMAH safety reports

The requirement in the 'Seveso II' directive to demonstrate that 'all measures necessary' have been taken to prevent and limit the effects of major accidents presents a considerable challenge to both the regulator in defining a suitable and sufficient approach and to those charged with writing safety reports. Based on practical experience of COMAH risk assessments for several companies, this paper will present the approach developed by ABB Eutech. It covers the key issues and challenges that have arisen, how these have been addressed, the results of initial, assessments and the direction of the regulator based on latest guidance. One of the key issues has been to demonstrate a proportionate approach whilst avoiding the excessive costs associated with extensive quantified risk assessments. The paper presents a screening methodology built around a semi-quantitative risk matrix that has been used successfully to make the necessary demonstrations. Recent guidance from the HSE is driving towards a greater level of quantification, especially for high consequence and high risk events, and these new requirements are discussed at the end of the paper.