A flash fire occurred during turnaround activities inside a petrochemical plant pressure vessel. Our investigation identified causal factors that led to the incident, including vessel preparation and confined space entry procedures. Our resulting opinion from the root cause analysis was submitted into evidence in litigation and facilitated settlement prior to trial.

Internal inspections and repairs on refinery or petrochemical plant vessels and other process equipment cannot normally be performed during operations. Instead, they are typically achieved during "turnarounds"-scheduled periods of maintenance during which contract organizations that have specialized expertise in performing such tasks are engaged. Due to the complexities and risks associated with such activities, worker safety is a high priority. To assist in assuring worker safety, operating companies are required to comply with various federal regulations, including the Occupational Safety & Health Administration's (OSHA) process safety management (PSM) standard for highly hazardous chemicals. However, a company's own maintenance and operating procedures provide a critical layer of safety to mitigate risks associated with such work activities. These procedures are developed by trained operators and maintenance personnel with intimate knowledge of specific plant, processes, and equipment.

During a turnaround at a petrochemical plant, a "flash" fire occurred in a pressure vessel after it had been cleared for entry and workers had already begun performing their work inside. A flash fire is a sudden, intense fire caused by ignition of a mixture of air and a combustible liquid or gas characterized by high temperature and short duration. Fortunately, no one was severely injured, and damage to equipment was minimal. However, because of differing views on who was at fault, Baker & O'Brien was retained to identify factors that may have contributed to the incident.

The flash fire occurred following several days of activities inside the vessel, after a work crew had already exited. It flashed outside of the vessel and quickly self-extinguished. In this particular case, prior to workers entering the vessel, it had been treated with a hydrocarbon solvent to remove as much residue as possible, and then flushed with water to remove all flammable liquids. Correctly performing such activities is important in order to clear the vessel of all hazardous and flammable materials before work activities begin.

Other preparation activities commonly include: (a) acquiring the proper tools and personal protective equipment needed for the work; (b) testing the atmosphere inside the vessel and assuring that proper safety work permits have been issued; and (c) communicating with and assuring that workers are properly trained for the work.

As part of their assignment, Baker & O'Brien consultants reviewed potential ignition and fuel sources, as well as contributing or root causes, such as inadequate procedures or non-adherence to procedures. Our consultants issued an expert report that was submitted into evidence in litigation. The case was eventually settled outside of court.