Investigation update on fatal BP-Husky refinery incident released

01 November 2022

The US Chemical Safety and Hazard Investigation Board (CSB) has released information related to its ongoing investigation of the chemical release and fire at the BP-Husky Refining Toledo refinery in Oregon, Ohio. The incident on September 20 killed two workers and resulted in a release of sulphur dioxide and hydrogen sulphide, as well as significant property damage.

Image: CSB

At about 18:46 local time, 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 (see image) 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, the CSB said. The Fuel Gas Mix Drum is primarily a vapour-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 fibres.

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.

In its update, CSB added that:

- BP, the Occupational Safety and Health Administration (OSHA), the United Steelworkers International and Local 1-346 are conducting parallel investigations of the incident.

- The CSB, OSHA, and BP-Husky Refining LLC signed an evidence and site control agreement to preserve evidence.

- BP, OSHA, and the United Steelworkers, which represents hourly workers at the refinery, have been cooperating with the CSB team.

The CSB will continue providing updates as the investigation progresses and additional information becomes available.