An investigation into the fatal chemical release and fire at the BP-Husky Refining LLC (BPHR) Toledo refinery in Oregon, Ohio, continues by the U.S. Chemical Safety and Hazard Investigation Board (CSB).

At about 6:46 p.m. on Tuesday, September 20, an accidental release of flammable chemicals ignited, creating a fire that fatally injured two employees and resulted in substantial property damage at the refinery. The CSB is examining the valves and interconnected piping associated with the refinery’s fuel gas mix drum located in the Crude 1 Unit.

The fuel gas mix drum was installed around 2016 and combines various sources of flammable gases for use as fuel in refinery furnaces and boilers. It is primarily a vapor-filled vessel and is equipped with features to remove liquids that could be entrained with vapor or that otherwise enter the refinery’s fuel gas system.

CSB investigators are focusing on a release of flammable naphtha from the fuel gas mix drum, based on information from various sources at the refinery. Access to the area surrounding the fuel gas mix drum is currently restricted due to the presence of asbestos fibers.

The CSB investigation team is conducting witness and employee interviews, documenting the incident scene, collecting equipment and equipment components, obtaining documents and evaluating recorded process data. The CSB team has already interviewed more than 80 people and anticipates interviewing 20-30 more.

BPHR is operated by BP Products North American Inc. (BP).