(52t) The Impact of the Tolerable Event Frequency Used during a Layer of Protection Analysis

The choice of tolerable event frequency (TEF) can have a big impact on the safeguards which must be put in place to mitigate a hazardous scenario. If it is too high, personnel may be exposed to a high level of risk, whereas if it is too low, there may be an unnecessary burden placed on operations and resources allocated to the wrong areas. Several case studies from the petrochemical industry were evaluated to show the impact of different values of TEFs and the impact on the process. Options for safeguards to meet these standards were compared and impacts on operability and cost were evaluated. By selecting an appropriate TEF, companies can achieve a balance between operability and safety and allocate resources more appropriately. This study aims at providing some insight into how to choose an appropriate TEF.