Industry News

CSB Investigates Hazardous Releases at Dow, Honeywell Performance Materials Plants

April 8, 2024

Agency turns its attention to accidental releases after closing investigation backlog.

By Jonathan Katz

The U.S. Chemical Safety and Hazard Investigation Board (CSB) has launched an investigation into toxic chemical releases from a Dow Chemical plant and a Honeywell Performance Materials facility, both located in Louisiana.

CSB said April 4 it’s looking into the release of hydrogen fluoride (HF) and chlorine at the Honeywell Performance Materials and Technologies facility in Geismar on Jan. 23, 2023, and the release of ethylene oxide (EtO) at the Dow Louisiana operations facility in Plaquemine in July 14, 2023.

A heat exchanger ruptured at the Honeywell facility in Geismar leading to an explosion and the release of approximately 870 pounds of hydrogen fluoride (HF) and 1,700 pounds 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.

Dow reported to the CSB that a detonation occurred in a pipe segment at the Plaquemine facility for an 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.

The companies reported the incidents to the CSB in accordance with the agency’s accidental release reporting rule. After clearing a backlog of investigation reports, the agency is now turning its attention to other serious chemical incidents logged under its 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,” he said in a news release. “We want to make sure that similar incidents do not happen again at these facilities.”