Individual and societal risk analysis and mapping of human vulnerability to chemical accidents in the vicinity of an industrial area

The hazards associated with major accident hazard (MAH) industries in industrial areas are fire, explosion and toxic gas releases and the domino effects associated with fire and explosions. Accidents such as the Bhopal tragedy in 1984, Jilin chemical plant explosion in China in 2005 and Jaipur (India) oil fire in 2009 have clearly demonstrated how the impact of industrial accidents can be severely amplified in areas adjacent to hazardous installations and high­density populations. Severe damage to human life and health caused by industrial accidents prompts reorienting emergency management from simple post­event response to preventive preparedness. Qualitative and quantitative hazard analyses are essential for the identification and quantification of the hazards related to chemical industries. Consequence analysis and Fault Tree Analysis (FTA) are established techniques in hazard identification and quantification. This paper presents the results of a consequence analysis carried out to assess the damage potential of the hazardous material storages located in an industrial area of central Kerala, India. The damage potential of the hazardous chemicals used in the various Major Accident Hazard (MAH) industries is assessed using consequence modelling. Modelling of pool fire for naphtha, cyclohexane, cylcoheanone, benzene and ammonia are carried out using TNO model. Vapor cloud explosion modeling (VCE) of LPG, cyclohexane and naphtha are carried out using TNT equivalent model. Boiling liquid expanding vapor explosion (BLEVE) modeling of LPG is also carried out. Dispersion modelling of toxic chemicals like chlorine, ammonia and benzene are carried out by using the ALOHA air quality model. These results are used for the estimation of individual risk and societal risk in the above industrial area. Vulnerability assessment is carried out using probit functions for toxic, thermal and pressure loads. Mapping of threat zones associated with different incident outcome cases from different MAH industries are also done with the help of Arc GIS. Individual and societal risk is also estimated at different locations due to different incident outcome cases. These results will be useful as operational tools for competent authorities, industrialists and risk experts to assess the vulnerability of the areas surrounding industrial