Over the last decades a significant need has developed for change regarding safety control in the process and storage industries. Past-accident analysis shows that most dangerous incidents are related to failure of process operations and/or associated equipment. In October 2009, a series of events triggered by the dearth of redundant level control measures led to the release of huge quantities of gasoline from a bulk storage of Indian Oil Corporation Limited (IOCL) facility at Sitapura near the Jaipur airport in India, preceded by Buncefield, UK (2005), Puerto-Rico, USA (2009). All the above episodic incidents involved much extended clouds with characteristic diameters in the range 400-1000 m. Such incident established the need to not only understand vapour cloud explosion (VCE), but also the importance of avoiding the escalation of minor incidents into much more devastating consequences. At 18:10 IST on 29th October 2009, a leakage of gasoline occurred from one of the storage tanks on the IOCL Petroleum Oil Lubricants Terminal at Jaipur, India. The leakage continued for about 75-90 min led to the release of almost 340-400 tons of gasoline and created a very large vapor cloud (approximate to 180,000 m(2)) over the entire installation. The delay ignition triggered a devastating VCE, which generated significant peak overpressure (> 200 kPa). The VCE was followed by a multiple tank fire (9 tanks immediate after VCE), which lasted for 11 days. This accident resulted 11 fatalities, more than 150 people were injured, and a property loss of approximately US $60 million was reported. From an incident investigation so far, it can be understood that the obstacle in the flame path will create the intensified flame velocity reaching the Deflagration to Detonation Transition (DDT) level. A detonation is an unusual event; however, it is the worst case accidental event. The detailed analysis of IOCL, Jaipur and other accidents reported have highlighted that a typical major accident is not the result of a single undesired event, but rather the consequence of a succession of failures at several levels. Therefore, it has been a key challenge to anticipate combinations of such failures and corresponding unidentified incident scenarios. Additionally, the consideration of DDT phenomena in hazard and risk assessment would identify new escalation potentials and identify critical impacted. This knowledge will allow a more effective management of this hazard. Two complementary approaches to deal with this challenge are: i) improved identification of a typical scenarios, to reduce the occurrence of unforeseen events; ii) improved early detection, to reduce the possibility of remaining unforeseen events leading to an accident.
