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Nov 7, 2005

CSB Investigators to Assess Fatal Nitrogen Incident at Valero Delaware City Refinery


Washington, DC, November 7, 2005 - Investigators from the U.S. Chemical Safety and Hazard Investigation Board (CSB) are en route to the Valero oil refinery in Delaware City, Delaware, where two contract workers were overcome and killed this weekend by entry into a nitrogen gas-filled process vessel.

Investigators Stephen Wallace, PE, and Francisco Altamirano are expected at the site later this afternoon. The team will gather preliminary information to assess whether the incident warrants further investigation by the CSB.

In August 2002, the CSB completed a year-long investigation of a fatal storage tank explosion at the same refinery, then owned by Motiva Enterprises.

In June 2003, the CSB issued a Safety Bulletin on the hazards of nitrogen asphyxiation, which identified 85 incidents in the U.S. between 1992 and 2002 that resulted in a total of 80 deaths and 50 injuries. The bulletin was prompted in part by the CSB's investigation of a nitrogen asphyxiation incident at a Union Carbide chemical plant in March 1998; one worker was killed and another severely injured when they entered a large process pipe that was being flushed with nitrogen.

More information is available from, including the full text of the CSB's Nitrogen Safety Bulletin, Union Carbide investigation report, and Motiva investigation report.

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, regulations, and industry standards. 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.

For more information, contact Daniel Horowitz (202) 261-7613 / (202) 441-6074 cell.




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