A dynamic individual risk management method considering spatial and temporal synergistic effect of toxic substance leakage and fire accidents

Actual chemical industrial park accidents usually involve multi-hazard accidents. Synergistic effect of accidents could lead to serious casualties. In order to reduce the individual risk of accidents, this work proposes a method for managing the dynamic individual risk when toxic substance leakage and fire accidents occur concurrently, in which spatial and temporal synergistic effect of above two accidents is considered. The synergistic effect may reduce individual escape ability, and is modeled by quantifying the relationship between escape ability and toxic substance dose. In addition, the method analyzes dynamic individual risk of a person receiving the thermal radiation dose and toxic substance dose when escaping along a certain route. The casualty degree is described by the injury degree based on dose thresholds and the total fatality probability based on Probit model. Combined with the accident scenario, the critical safety escape distance is obtained. The model is proposed to plan the individual escape route based on the risk assessment results. The critical values of toxic substance concentration and thermal radiation intensity are defined as the basis for planning alternative escape routes. Finally, the optimal escape route is obtained according to the total fatality probability of each route. The range of safe escape direction can be used when wind direction information is inaccurate. A case study demonstrates the effectiveness of the proposed method and risk management strategy.