A Risk-Informed Community Framework for the Assessment of Chemical Hazards

Abstract

We present the Data and Risk-Informed Chemical Assessment Technique (DRICAT), a quantitative/qualitative risk analysis technique for assessing the risk of a potential chemical release incident that may lead to a mass casualty event in United States communities. Risk assessment is a comprehensive, structured, and logical analysis approach aimed at identifying and assessing risks in “systems” for the purpose of improving management of these systems. DRICAT leads to better understanding and effective management of risks from chemical incidents through risk and scenario identification and ranking by severity by helping community planning to min-imize morbidity and mortality during and after potential events. As such, DRICAT is designed to be reproducible, evidence-based, practical, and scalable for different types of communities and the possible chemical hazards present in that community. Recognizing that many communities have assessment protocols and response mechanisms already in place, we believe these DRICAT character-istics will enhance both existing chemical incident awareness and readiness activities while providing a baseline approach for communities lacking chemical release risk analysis techniques. To understand where potential hazards might exist within a com-munity, it is useful to consider drivers for hazards (i.e., those factors that influence the presence of the hazards and the uncertainty). DRICAT uses essential elements of information (EEI) to identify chemical initiating events (IE) which are a part of potential hazardous scenarios. Both formal and informal approaches can be used to identify initiators arising from chemical hazards. DRICAT fo-cuses on precursor events and a deductive approach using a hazard identification diagram. EEI data sources for community chemical hazards range from informal (e.g., social media, and local news outlets) to formal vetted databases. EEIs include systematic identification of hazards, community factors that affect hazards (e.g., population density, weather, and commodity flows), associated IEs, and grouping of individual causes into like categories. IE charac-teristics may vary among communities and include IEs that may lead directly to a chemical release or may require additional miti-gative failures. DRICAT leverages EEIs to identify IEs to build and rank chemical accident scenarios from IE to the potential outcome. The likelihood of this release and the consequence of the release determine the overall risk.