Trends, problems and outlook in process industry risk assessment and aspects of personal and process safety.

Process industry brings economic activity and provides us with unique materials. Inherent to it are risks of loss of containment of hazardous substances and the ensuing risks of explosions, fires and toxic spread. Risk assessment as an instrument to describe and delimit the risk of chemical process operations was introduced to the community of Loss Prevention in the process industry in the mid-seventies. Many data have been collected and much has been said about interpretation of results. The latter has been an infinite source of quarrels. Meanwhile, the use of risk assessment has become rather widespread and more decision making depends on it. Not only installations bound to a certain location, but also transportation routes have been object of risk analysis and assessment. Yet, the methodology produces still unsatisfactory results. This paper will start off presenting a statistical study on petrochemical accidents over the long period to evidence the need of developing and strengthening control barriers to prevent catastrophic consequences to people or environment resulting from accidental releases of hydrocarbons. The paper will continue describing what is meant with risk assessment, where it is used for and why and what trends can be seen. It will briefly summarise experiences in the Netherlands and elsewhere. It will then try to analyse the underlying problems as there are the subjectivity in hazard identification, oversimplification in release models, assumptions in environmental conditions (weather, terrain), the large uncertainties in failure mechanisms and failure rates, and the deficiencies in consequence modelling. The paper will further try to give a perspective of promising developments, highly needed cooperative efforts on e.g. a European scale to give relief to the larger demands in a more complex and economically striving society which puts a high value to overall safety and security. At last, an approach to process and personal safety management is presented, derived from a process industry case-study and including human behaviour evaluation, as well as the implementation of a set of lagging and leading safety indicators.