Safety standards changed as a result of the hydrocarbon explosion and fire that killed seven workers at the Tesoro Corp. Anacortes, WA, refinery in April of 2010.
More than a year after the deadly blast, the San Antonio-based company released on a report confirmed through an internal report the cause of the explosion.
A “high temperature hydrogen attack” ruptured a heat exchanger, the company said. A hydrogen attack happens when hydrogen mixes with carbon.
Among the new safety initiatives, the company said new heat exchangers will minimize the risk of hydrogen attacks.
The state Department of Labor and Industries had previously concluded Tesoro failed to inspect cracks that developed in the nearly 40-year-old heat exchanger that ruptured. The state fined Tesoro $2.39 million.