CSB Updates Investigation on 2023 Toxic Chemical Release

The US Chemical Safety and Hazard Investigation Board (CSB) just released an update on its investigation into a July 2023 explosion at the Dow Louisiana Operations’ Glycol II plant in Plaquemine, LA that resulted in the release of over 31,000 pounds of ethylene oxide (EtO), a known carcinogen.

Multiple subsequent explosions and fires damaged nearby piping and equipment, including a reflux drum. In addition to the release of EtO, the incident resulted in substantial property damage at the facility, and a shelter in place was ordered for hundreds of nearby residents.

The CSB launched a team to the site of this investigation on April 4, 2024, after the agency eliminated CSB’s long-standing backlog of investigation reports.

“Because we completely eliminated the CSB’s long-standing backlog of investigation reports that developed under prior agency leadership, we now are able to investigate serious chemical incidents, like this one at the Dow facility, that were reported to the CSB under the Accidental Release Reporting Rule," said CSB Chairperson Steve Owens. "Fortunately, no one was seriously injured during this incident, but workers and nearby residents could have been put at serious risk under different circumstances.”

The CSB now has identified several events of concern that occurred during this incident, including high vibration in a reflux pump, upsets in the EtO finishing process, and multiple explosions and fires, and ultimately the release of 31,525 pounds of EtO, a cancer-causing substance. Investigating the root causes of each event will be crucial in understanding and preventing similar incidents in the future.

The CSB is continuing to gather facts and analyze several key areas involved in this incident, including:

The CSB’s investigation of this incident is ongoing. Complete findings, analyses, and appropriate recommendations will be detailed in the CSB’s final investigation report.