UNCERTAINTY IN THE RISK ASSESSMENT PROCESS - THE CHALLENGE OF MAKING REASONABLE BUSINESS DECISIONS WITHIN THE FRAMEWORK OF THE PRECAUTIONARY PRINCIPLE

摘要

Risk assessments can easily provide an illusion of certainty that hazards have been comprehensively identified and thoroughly understood. The logical and systematic assessment framework is often, however, simply a best estimate of reality based on the views of a range of experts at a given point in time. In practice, a degree of uncertainty is associated with every stage of the risk assessment process from obtaining the fundamental physical, chemical and hazardous properties of materials to scaling data from the laboratory to the plant to the technical methodologies that are used for analysing risks. Some risks are never assessed because the fundamental hazards have not been identified. Other risk assessments use underpinning assumptions that can change with time. All of these factors create uncertainty. This paper identifies sources of uncertainty supported by real examples to illustrate how the wrong decisions can be made in risk assessments and how some decisions still rely heavily on expert judgement. Commonly used techniques for assessing uncertainty are then reviewed and the paper concludes by examining how operating companies can reasonably manage uncertainty within the context of the precautionary principle, the global economy and the range of risks that people are exposed to in their lives.