What do gas blows, iron dust accumulations and sulfidation corrosion have in common?

This paper presents an analysis of three process incidents recently investigated by the US Chemical Safety Board (CSB): (i) Kleen Energy natural gas explosion (Middletown, CT), (ii) Hoeganaes Corporation iron dust flash fires and hydrogen explosion (Gallatin, TN), and (iii) Chevron Richmond refinery pipe rupture and fire (Richmond, CA). The starting point for the analysis is identification of the main hazardous materials, activities or conditions underlying the specific incident losses. These are, respectively: (i) Kleen Energy - purging of process pipelines with natural gas, (ii) Hoeganaes Corporation - accumulations of combustible iron dust in work areas, and (iii) Chevron Richmond refinery - a pipeline damage mechanism known as sulfidation corrosion. While the three incidents have many aspects in common, chief among the similarities are the key process safety concepts of inherently safer design (ISD), recognition of warning signs (precursor events), and safety culture. Each incident is analyzed for evidence of these concepts. The analysis is drawn from the relevant CSB investigation reports with the primary objective of illustrating the strong experiential learning that case histories of actual incidents can provide. While the lessons learned from these incidents are useful in and of themselves, capturing these lessons by incorporation in a safety management framework extends their usefulness to the prevention and mitigation of other potential process incidents. A typical process safety management system is employed in the current work to accomplish this secondary objective. Overall conclusions are made concerning the effectiveness of ISD, precursor recognition, and safety culture with respect to risk reduction in the process industries. It is anticipated that this work will help in communication of lessons learned to both the research and practice communities.