Accidents in chemical industry: are they foreseeable?

‘Accidents recur,’ which is what Kletz [Kletz T. (1993). Lessons from disasters, how organisations have no memory and accidents recur. UK: Institution of Chemical Engineers] wrote in 1993. Indeed, despite all measures taken accidents may re-occur, but ‘disruptions’ in a process reoccur much more frequently. If a disruption occurs it may lead to an accident. If the same disruption reoccurs it is certainly suspect and should be considered as a potential precursor. In this paper, we concentrate on these disruptions and we will define them as precursors if they recur. Organizations somehow lack the ability to control such recurring disruptions that may escalate into serious accidents under certain circumstances. The presence of such precursors long before the occurrence of an accident raises doubts about how well organizations control safety. In this paper, the control mechanism inside organizations is examined, by means of several accident investigations. It will be shown that not only accidents recur, but also that disruptions recur in a period preceding the actual accident. The recurrence of these disruptions implies that the corresponding organizational control mechanism must be failing. Often, alternative circumstances prompt the escalation of such precursors and lead to actual accidents. It is demonstrated that the use of detailed accident information is of great importance for companies that are actually willing to prevent accidents through the elimination of disruptions preceding accidents. Keywords: Process safety; Accident; Precursor; Prevention; Knowledge base