An Analysis of CSB Investigation Reports for Inherent Safety Learnings

摘要

Sixty reports resulting from process incident investigations conducted by the U.S. ChemicalSafety Board (CSB) have been analyzed for evidence of examples related to inherent safety,passive and active engineered safety, and procedural safety. These risk reduction measures,which collectively form the hierarchy of safety controls, were also analyzed for their contributionto both incident prevention and consequence mitigation, as well as their applicability to specificelements in a recognized process safety management (PSM) system.Over two hundred examples from the hierarchy of controls were identified with the followingbreakdown: inherent safety (36 % of total overall examples), passive engineered safety (8 %),active engineered safety (14 %), and procedural safety (42 %). Numerous examples for bothprevention and mitigation measures were found during the CSB report review. Inherently saferdesign (ISD) items were observed to be nearly equally split among the four primary principles ofminimization (25 % of total ISD examples), substitution (22 %), moderation (25 %), andsimplification (27 %). Widely applicable PSM elements (in terms of a link to the identifiedhierarchical safety measures) were determined to be process and equipment integrity, trainingand performance, process knowledge and documentation, capital project review and designprocedures, and management of change.The results from the current work are generally consistent both qualitatively and quantitativelywith that of other workers who examined incidents investigated by the CSB and other agencies.CSB reports themselves afford multiple opportunities to learn and reinforce the concept ofinherently safety design and its relationship to other available safety measures. The value ofthese reports in demonstrating lessons learned and in training/educational efforts is significant.