Washington, DC, August 3, 2004 - The U.S. Chemical Safety and Hazard Investigation Board (CSB) investigation into the Giant Industries explosion and fire continues, focusing on several areas. The April 8 accident at the company's Ciniza refinery east of Gallup, New Mexico, seriously injured four workers when highly flammable gasoline components were released and ignited.
The CSB's investigation will continue for a number of months, at which point the agency will release findings and determinations of the root causes of the accident. Board spokesman Daniel Horowitz said CSB is pursuing several lines of investigation, including examining the condition of a shut-off valve that allowed the hydrocarbon leak. The release occurred as workers were removing a malfunctioning pump from the refinery's alkylation unit, which produces highly flammable hydrocarbon known as "alkylate," using hydrofluoric acid (HF) as a catalyst. Unknown to personnel, a shutoff value connecting the pump to a distillation column was apparently in the open position, leading to the release of alkylate vapor and subsequent explosions.
"Examinations indicate that the valve was not properly assembled, and the handle position did not accurately reflect the internal position of the valve," Dr. Horowitz said. "This may have led workers to believe that the valve was safely closed when in fact it was open."
In addition, CSB investigators are assessing the adequacy of the refinery's design, operation, and maintenance practices for preventing the release of hazardous materials from vessels and piping systems. Specifically, investigators are reviewing the refinery's procedures for blocking off or isolating lines that contain hazardous materials prior to undertaking maintenance work. The CSB is also examining equipment and process conditions upstream of the malfunctioning pump that caused sludge to accumulate in the piping, necessitating repeated maintenance on the pump over the year previous to the accident. CSB investigators are seeking to determine whether sludge could have temporarily stopped the flow of alkylate in the piping and prevented workers from realizing that the valve was open until there was a sudden release of pressurized material.
The CSB is an independent federal agency charged with investigating industrial chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in safety management systems.
The Board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA. Further information about the CSB is available from www.csb.gov. For more information, contact Sandy Gilmour (Public Affairs Contractor), 202-261-7614 / 202-251-5496 (cell), or Daniel Horowitz, 202-261-7613.