An assessment of the likelihood of occurrence, and the damage potential ofdomino effect (chain of accidents) in a typical cluster of industries

in the context of risk assessment and loss prevention in chemical process i ndustries, the term domino effect denotes 'chain of accidents: or situation s when a fire/explosion/missile/toxic load generated by an accident in one unit in an industry causes secondary and higher order accidents in other un its. Most of the past risk assessment studies deal with accident in a singl e industry, more so in one of the units of an industry. But, often, acciden t in one unit can cause a secondary accident in a nearby unit, which in tur n may trigger a tertiary accident, and so on. The probability of occurrence and adverse impacts of such 'domino' or 'cascading effects are increasing due to increasing congestion in industrial complexes and increasing density of human population around such complexes. The multi-accident catastrophe which occurred in a refinery at Vishakhapatnam, India, on 14 September 1997 , claiming 60 lives and causing loss of property worth over Rs 600 million, is the most recent example of the damage potential of domino effect [Lees F.P. Loss prevention in process industries, 2nd ed. Butterworths. 1-3, Lond on; Khan, F.I., & Abbasi, S.A. (1999a). Major accidents in process industri es and an analysis of their causes and consequences. Journal of Loss Preven tion in Process Industries, 12, 361-378: Khan, F.I., & Abbasi, S.A. (1999b) . The worst chemical industry accident of 1990's-what happened and what mig ht have been: A quantitative study. Proress Safety. Progress, 18, 135-145]. Recently, we have proposed a systematic methodology called 'domino effect analysis' (DEA). A computer automated tool DOMIFFECT has also been develope d by us based on DEA [Khan, F.I., & Abbasi, S.A. (1998a). Models for domino effect analysis in chemical process industries. Process Safer?: Progress - AIChE, 17 (2), 107-113; Khan, F.I., & Abbasi, S.A. (1998b). DOMIFFECT (DOM Ino eFFECT): a new software for domino effect analysis in chemical process industries. Environmental Modelling and Software, 13, 163-177.]. The method ology is based on deterministic models used in conjunction with probabilist ic analysis. This paper illustrates the application of DEA and DOMIFFECT to an industrial complex. Out of 16 credible accident scenarios envisaged in four closely situated industries namely Madras Fertilisers Limited (MFL), S PIC-Heavy Chemical Division (SPIC-HCD). Manali Petrochemical Limited (MPL), and Tamilnadu Petroproducts Limited (TPL). ten scenarios forecast domino e ffect. Further analysis reveals that accidents in the ammonia synthesis uni t, secondary reformer, and urea reactor of MFL may cause domino effect. Sim ilarly, accidents in the storage units of propylene oxide, ethylene oxide a nd mono propylene glycol at MPL, hydrogen storage units at SPIC-HCD, and th e propylene oxide and fuel oil storage units of TPL are likely to cause a d omino effect. The consequences of all these credible accidents have also be en forecast. The paper makes a strong case for making DEA an integral part of all risk assessment initiatives. (C) 2001 Elsevier Science Ltd. All righ ts reserved.