SEATTLE — A scathing report from federal safety investigators on the deadly Tesoro refinery explosion in Anacortes said the oil company is to blame.
The 146-page report squarely places the blame for the explosion on Tesoro, but also calls for industry-wide changes to prevent future accidents.
The U.S Chemical Safety Board also released an animated video that describes in detail what caused the explosion and fireball that killed seven workers at the Tesoro plant in 2010.
The 4-year investigation found that over time, high-temperature hydrogen in the pressurized heat exchangers used to purify crude oil at the plant had caused tiny cracks in the steel pipes.
The morning of the explosion, one of those cracks ripped open.
The board also announced two of the biggest factors in the explosion. One was the lower-grade steel used in Tesoro's heat exchanger pipes.
Even though it met regulations, federal investigators think stronger steel should be used.
The second factor was that Tesoro was "complacent" and hadn't fixed flammable leaks at the facility, according to the report.
The report calls on the U.S. Environmental Protection Agency to work with the industry to come up with a new regulation requiring chemical facilities to make their operations inherently safer, such as replacing a material with one that's less hazardous or reducing the amount of hazardous material stored and used.
It also recommends that state regulators audit all petroleum refineries in the state to prevent the kind of equipment failure that occurred at Tesoro's facility.
In a statement about Thursday's report, Tesoro fought back about the allegations of complacency, saying:
"We respectfully disagree with several findings in the draft report and, most importantly, take exception to CSB's inaccurate depiction of our process safety culture."
The blast was the deadliest refinery incident in the U.S. since a 2005 explosion killed 15 people and injured 180 at a BP refinery in Texas City, Texas.
KIRO
