Mar 26, 2005
CSB Investigation of BP America Texas City Tragedy Continues as Investigators Prepare to Enter Blast Site; Investigators Focusing on "Raffinate Splitter" within Refinery Isomerization Unit
Texas City, Texas, March 26, 2005 - The U.S. Chemical Safety and Hazard Investigation Board (CSB) continued its investigation today of the March 23 tragedy at the BP America Texas City refinery, as investigators prepared to enter the explosion site for the first time. Entry is expected as early as Monday when appropriate air monitoring equipment is in place.
Fifteen workers were killed and about 100 were injured in the incident which occurred about 1:20 p.m. on Wednesday, March 23. A number of the injured remained hospitalized in intensive care, some with critical trauma and burn injuries.
Final site safety arrangements were in progress Saturday afternoon, in preparation for entry using protective clothing and gear known as Level D. CSB team members have inspected the perimeter of the blast area. Investigators have also interviewed more of the plant operators who were on duty at the time of accident.
Additional investigators and specialists have been dispatched to the site from Washington, DC, and other locations. About one dozen investigators should be in place at the refinery by Monday. On Saturday, a CSB team was also examining homes and businesses in the vicinity of the plant, many of which had broken windows due to blast overpressure. Those structures were located approximately one-half mile north of the plant.
Investigation Manager Steve Selk said: "Process equipment within the explosion site shows substantial thermal damage and limited blast damage, consistent with a flash fire of flammable hydrocarbon in the open atmosphere. Trailers adjacent to the isomerization unit were very heavily damaged or destroyed. The walls and roof of an adjacent metal warehouse used to store catalyst were heavily damaged as well."
It was not immediately clear how many trailers had been present or what materials they were made of, but Selk said that typical mobile trailers would be much less resistant to blast effects than permanent, protected structures such as control rooms that are often found at large refineries and chemical plants. The trailers were used by contract workers performing maintenance operations at the refinery.
Board member John Bresland said, "The placement of the trailers in close proximity to an operating refinery unit is one factor we will be focusing on as the investigation proceeds." Bresland said the team would also be looking into company reports of a small fire in the isomerization unit the day before, but said there was not presently any evidence to link the fire with the explosion Wednesday afternoon.
Mr. Bresland said, "This was a profound tragedy for Texas City and the entire region. We offer our deepest sympathies to all those who were affected by this terrible accident, and we will expend every effort to determine its root causes and prevent its recurrence here or elsewhere." Bresland added that the Board would likely convene one or more community meetings as the investigation proceeds. Such meetings typically are convened at the midpoint of the investigative process, which can take one to two years to complete, but Bresland did not rule out earlier public hearings if circumstances warrant.
The isomerization unit converts the chemicals pentane and hexane into isopentane and isohexane in order to boost the octane rating of gasoline. The unit works by heating feedstock in the presence of a catalyst. Investigators are currently focusing on equipment associated with a "raffinate splitter." This equipment comprises a distillation system that is used to prepare the feed stream for the isomerization reactor. Preliminary evidence points to a release of flammable liquid and vapor in that area of the plant. The distillation equipment was being restarted following maintenance work on the reactor a few days earlier. Pentane and hexane are both highly flammable.
The CSB root-cause investigation will likely include examination of blast patterns to determine the explosion origin; review of the design of the isomerization unit equipment; and examination of plant safety and operating procedures, past accidents, maintenance procedures, and oversight and inspection. Investigators will also review the adequacy of applicable regulations and industry standards for the placement of temporary structures such as trailers in refineries.
The CSB is an independent federal agency charged with investigating industrial chemical accidents. Agency 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 Daniel Horowitz (202) 441-6074 or Sandy Gilmour at (202) 251-5496.