Final report released on DeRidder plant explosion
Emergency response personnel were at the scene after what authorities said was an explosion of two tanks at DeRidder’s PCA Plant on February 8, 2017. Three were confirmed dead and three more injured. (Pamela Sleezer/American Press)
The U.S. Chemical Safety Board released its final report Tuesday into the Feb. 8, 2017, explosion at the Packaging Corporation of America plant in DeRidder.
The explosion occurred at the company’s pulp and paper mill during “hot work,” or welding activities, that took place during the facility’s annual shutdown, according to chairperson Vanessa Allen Sutherland.
Sutherland said Tuesday during a conference call that when the explosion occurred, both contract workers and PCA employees were working to repair a cracked condensate tank that contained about 10 feet of “foul condensate.”
She said that at the time the repairs were being made, it was believed by PCA that the tank only held water but that it in fact contained residual turpentine that became flammable when exposed to the atmosphere and the welding tools.
The resulting explosion caused the 100,000-gallon tank to fly 60 feet in the air, separate into two parts and launch over a nearby six-story structure, she said. Three contract workers were killed, and seven more were injured.
CSB investigator Jared Denton said that during the normal, correct process, the tank would catch flow from upstream and downstream of the plant and the residual turpentine would be skimmed from the water before reaching the tank. Prior to the February explosion, he said, the turpentine was not being properly removed.
Denton said that in the months before the explosion, there was confusion over who exactly had ownership of the tank, and thus who was responsible for its operations.
He did say that prior to the repairs beginning, workers used a combustible gas detector to test for a flammable atmosphere outside the tank but that they were unaware of the mixture of air and turpentine that was accumulating inside the tank.
“The CSB believes that PCA missed opportunities to prevent this incident from occurring and likely could have been avoided,” Sutherland said.
She said the CSB found four main processes that PCA could have conducted to avoid such a tragedy: a process hazard analysis for the non-condensate gas system; applying safeguards; evaluating safer design options that would have prevented air from entering the tank; and establishing proper ownership and responsibility over the tank.
Sutherland said those recommendations are being submitted to PCA for future application, in addition to a 2002 recommendation the Occupational Safety and Health Administration made to cover the atmospheric storage tanks that are interconnected to a covered process — which would include the foul condensate tank that exploded.
She said that while the findings will not make the loss of the three workers any less tragic, the lessons learned can be used to make future safety changes.
“Our goal through all of this is to prevent future incidents from happening,” she stated.
While the CSB does not impose fines or penalties, OSHA formally noted five safety violations and assessed $63,375 in penalties against the DeRidder mill in December in regard to the explosion.
Denton said PCA is contesting the fines.
PCA has multiple other facilities across the nation, but Sutherland said the DeRidder incident will not prompt investigations into the processes at those other facilities.
“We do not typically conduct proactive investigations,” she said.
An animated illustration of the mill’s explosion was released by the CSB on April 18 and remains available for viewing at the board’s website, www.csb.gov.