Process safety in hindsight—When the hose breaks during bulk chemical transfer

Oleum, also known as “fuming sulfuric acid,” is a chemical commonly used for a variety of processes, such as sulfonation, nylon manufacturing, dye production, nitration, and hydrofluoric acid production. It is also a highly hazardous material regulated under the Environmental Protection Agency Risk Management Program and the Occupational Safety and Health Administration Process Safety Management standard. This paper is based on an oleum release incident that occurred during bulk unloading from railcar to chemical reactor via flexible hosing, resulting in injury to operating personnel. A post‐incident investigation supported the determination of contributory causes. This case study describes the sequence of events and decision‐making that led to the subject release, while also providing lessons learned with respect to process safety management. To illustrate the utility of appropriate consequence and hazard analysis techniques, we have applied typical methodologies and calculational tools to the activities surrounding the incident. Although these are applied in hindsight, they provide useful linkage between real events and lessons that can be delivered through these techniques. This paper applies computational consequence evaluation and simplified What‐If/Quantitative Risk Assessment techniques to fully characterize consequence associated with the release of highly hazardous materials during non‐standard bulk transfer operations.