U.S. Chemical Safety Board officials found common threads -- including poor maintenance practices, ineffective warning alarms, and insufficient accident investigations -- among the three incidents that occurred over a 33-hour period Jan. 22-23, 2010.
Chief among the findings was that nearly 25 years ago DuPont rejected proposals to enclose the Belle plant's phosgene unit, a move that would have protected workers and local residents from the poisonous material used as a chemical weapon in World War I.
CSB investigators also concluded that the most serious of the incidents, a fatal phosgene leak, was caused by the use of the wrong type of chemical hose and DuPont's failure to replace even that inadequate hose on its own required schedule.
"These kinds of findings would cause us great concern in any chemical plant -- but particularly in DuPont with its historically strong work and safety culture," said CSB member John Bresland, a longtime chemical plant manager and one-time DuPont lab technician. "In light of this, I would hope that DuPont officials are examining the safety culture company-wide."
Board Chairman Rafael Moure-Eraso said, "Tragedies can occur even with companies with highly-regarded safety cultures" and urged Kanawha Valley and West Virginia officials to create a local chemical plant accident prevention program.
DuPont officials said that they are reviewing the CSB report, but had already taken a variety of steps to improve safety procedures based on their own internal review of the incidents.
"Safety is a core value at DuPont and is our most important priority," company spokesman Dave Hastings said. "Our goal is zero -- meaning we believe all incidents and injuries are preventable."
In their 172-page report, CSB investigators focused on the Jan. 23, 2010, phosgene leak that killed plant worker Danny Fish. Agency experts also examined a methyl chloride leak that went on for five days before being discovered on Jan. 22, 2010, and a release of the chemical oleum the same morning as the deadly phosgene leak.
The report was issued in draft form. It won't be finalized until after a 45-day comment period that ends Aug. 22 and until the board approves the final version.
CSB officials found that the methyl chloride leak occurred when excess pressure caused a "rupture disc" to burst as designed to relieve that pressure.