A Screening-Level Multi-Criteria Decision-Support Framework for Prioritizing Dual-Use Chemical Scenarios in Emergency Preparedness

The increasing availability of dual-use chemicals has created emerging challenges for chemical emergency preparedness and CBRN risk management. Unlike conventional single-agent hazards, dual-use chemicals may be combined, diverted, or repurposed in ways that complicate regulatory control, early detection, and operational response. However, existing risk assessment approaches remain largely oriented toward individual hazardous substances and provide limited support for systematically prioritizing dual-use chemical scenarios. This study proposes a screening-level multi-criteria decision-support framework for evaluating dual-use chemical scenarios in emergency preparedness contexts. The framework integrates four key criteria—toxicity, reactivity, accessibility, and detection difficulty—and applies an expert-based semi-quantitative scoring model using Analytic Hierarchy Process (AHP)-derived weights to representative scenarios in high-risk public environments, including transportation hubs and urban public spaces. The results show that operational risk is not determined by toxicity alone. The TATP scenario produced the highest relative priority score, followed by VX binary and sarin precursor scenarios, indicating that accessibility and reactivity can substantially influence risk prioritization when combined with detection difficulty. These findings demonstrate the need to incorporate both intrinsic hazard characteristics and operational response constraints into CBRN preparedness planning. The proposed framework provides a practical tool for preliminary risk screening, scenario prioritization, emergency response planning, regulatory review, and inter-agency coordination for emerging dual-use chemical risks.