A four-member investigative team from the U.S. Chemical Safety Board (CSB) is deploying to the scene of an explosion and fire overnight in a naphtha hydrotreater unit at the Tesoro refinery in Anacortes, Wash.

Four workers were reported to be killed and four were hospitalized for burns.

Currently, the board is investigating an October 2009 flash fire at a Tesoro Refinery in Salt Lake City, Utah, that occurred when flammable liquid overfilled a flare stack and ignited.

CSB chairman and CEO John Bresland said, “The CSB has eighteen ongoing investigations. Of those, seven of these accidents occurred at refineries across the country. This is a significant and disturbing trend that the refining industry needs to address immediately.”

The team will be led by CSB investigatons supervisor Robert Hall, PE. Board member William B. Wark will accompany the team.

Chairman Bresland said the large-scale deployment to Washington State will further complicate efforts to complete other important cases, including the CSB’s investigations of the Caribbean Petroleum fuel terminal fire near San Juan, Puerto Rico; the CITGO refinery hydrogen fluoride release and fire in Corpus Christi, Texas; the Goodyear heat exchanger rupture and ammonia release in Houston; and the Exxon Mobil refinery hydrogen fluoride release in Joliet, Ill.
The CSB is an independent federal agency charged with investigating serious 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 regulations, industry standards, and safety management systems. Visit the CSB’s Web site at www.csb.gov