CSB Investigating 2 Toxic Chemical Incidents

The US Chemical Safety and Hazard Investigation Board (CSB) has launched investigations into toxic chemical releases at two facilities in Louisiana during 2023: the release of hydrogen fluoride (HF) and chlorine at the Honeywell Performance Materials and Technologies facility in Geismar in January 2023, and the release of ethylene oxide (EtO) at the Dow Chemical Louisiana Operations facility in Plaquemine in July 2023.

“Because we recently completely eliminated the CSB’s long-standing backlog of investigation reports, we now have the ability to address other serious chemical incidents reported to the agency under the Accidental Release Reporting Rule," said CSB Chairperson Steve Owens. "Fortunately no one was seriously injured or killed in either of these two events, but both involved the release of highly toxic chemicals — hydrogen fluoride and chlorine at the Honeywell facility and ethylene oxide at the Dow facility — that could have put workers and nearby residents at serious risk under different circumstances. We want to make sure that similar incidents do not happen again at these facilities.”

On Jan. 23, 2023, a heat exchanger ruptured at the Honeywell facility in Geismar, LA, resulting in an explosion and the release of approximately 870 lb of hydrogen fluoride (HF) and 1,700 lb of chlorine. Local officials closed nearby highways, and workers at the facility sheltered in place. No injuries were reported. Property damage at the facility is estimated to be $4 million.

On July 14, 2023, a fire and explosion occurred at the Dow facility in Plaquemine, LA. Dow reported to the CSB that a detonation occurred in a pipe segment for an ethylene oxide (EtO) pressure relief system within a glycol manufacturing unit. Hot combustion gases subsequently entered a distillation column reflux drum, creating high-pressure conditions that ruptured the pressure vessel. EtO that passed through the rupture disc contacted air within the downstream piping, triggering a fire and an explosion.

Local officials ordered a shelter-in-place for hundreds of residents within a half-mile of the plant. No injuries were reported. The dollar amount of the property damage has not yet been determined.