A publication of CHEMICAL ENGINEERING TRANSACTIONS VOL. 31, 2013 The Italian Association of Chemical Engineering Online at: www.aidic.it/cet Guest Editors: Eddy De Rademaeker, Bruno Fabiano, Simberto Senni Buratti Copyright © 2013, AIDIC Servizi S.r.l., ISBN 978-88-95608-22-8; ISSN 1974-9791 A Propane Fire Connected to Dumping Procedure in a Process Plant Daniele Cermelli*, Fabio Currò, Renato Pastorino and Bruno Fabiano DICCA – University of Genoa, via Opera Pia 15 – 16145 Genoa – Italy daniele.cermelli@gmail.com A propane gas cloud was released into the atmosphere during the loop rector dumping procedure in a process plant. After reactor inertization, the bottom valve of the dump tank was opened to collect spent powder and remove it. Unexpectedly, the powder on the floor started evaporating hydrocarbons. A propane cloud drifted very fast through the plant and ignited at the pump station area: even if the flash fire was extinguished immediately, there were several people injured and one fatality. The fire of the powdered material was extinguished later, by sprinkler system and fire brigade intervention. A detailed investigation was carried out and a multi-step methodology was applied to define the sequences and identify the most likely causes of the accident. It was adopted a complete fault tree, trying to find out without a structured scheme any critical causal factor in each relevant branch. Then, starting from the immediate cause, different sub-steps were identified as possible underlying cause, allowing to evidence in a sort of causal chain possible deficiencies in the safety management system, or in the safety culture of the company. Conclusions are drawn about practical recommendations to improve safety in dumping activities within a polymerization plant, adopting as well possible leading indicators for potential major incidents. The presented case study clearly shows how an effective HSE management system and a corresponding organization could have prevented or minimized the occurrence of such an unwanted event. 1. Introduction As amply recognized, learning from accidents is essential for improving safety, so as to address possible inadequacies and prevent future occurrences. In recent high profile accident investigations (e.g. BP Texas City, Deepwater Horizon) it was evidenced that good records of lost time accidents LTA (or other safety indicators, such as frequency index FI and fatal accident frequency index FAFR), not only do not provide effective precursors for major process accidents, but can also lead to a sort of “complacency”. In addition, as remarked by Kletz (1993), LTA has only limited value and should be supplemented by other measurements, such as the total accident rate, the cost of the damage caused by accidents and other dangerous incidents and, if possible, a numerical measure of the results of plant audits. Long-term studies on these indicators (e.g. Fabiano et al., 1998), put in evidence the positive trend over one century with declining trends in the number and rates of occupational fatalities and injuries for more than three decades in the chemical sector. Given this observation, there is a strong need to enforce a reporting culture and organizational climate that creates the conditions for collecting and analyzing process and plant safety near misses. A detailed reporting system, with a multi layer approach, can help in linking immediate causes of a near-miss to underlying causes that should be controlled by middle or higher management, or are parts of the corporate safety culture (Fabiano and Currò, 2012). In this way, it may be possible to identify appropriate leading indicators specific for the establishment under examination. In a recent survey on chemical process industry, based on the Failure Knowledge Database (Kidam et al., 2010), it was evidenced that accidents related to chemical handling, maintenance and cleaning work are significantly caused by poor management of plant operations. 565