On April 2, 2010, heat exchangers at a Tesoro Petroleum refinery in Anacortes, Washington, exploded, killing two female and five male company employees. After six months of investigations, the Washington State Department of Labor and Industries (L&I) announced it had issued a $2.39 million fine against Tesoro — the largest fine in the agency’s history.
According to L&I, a heat exchanger at the Tesoro refinery ruptured around 12:30 a.m., releasing volatile hydrocarbon vapor, which ignited almost immediately upon its release. L&I officials said the resulting explosion was the worst industrial disaster in the 37 years that the agency has been enforcing the Washington Industrial Safety and Health Act, the state’s workplace safety laws.
“The loss of seven lives is a tragedy not just for their loved ones but for our entire state. What makes the loss of these lives all the more painful is that these deaths could have been prevented,” Washington’s Governor Chris Gregoire said. “I believe the action L&I is announcing today and the record fine they have assessed against Tesoro sends a clear message that these tragedies are not acceptable.”
L&I cited Tesoro for 39 willful violations and five serious violations of state workplace safety and health regulations. A willful violation occurs when the employer knowingly violates a rule and is plainly indifferent to correcting it, while a serious violation is one involving an instance where there is a substantial probability of serious injury or death.
L&I inspectors discovered that Tesoro ignored a spectrum of safety regulations, continued to operate failing equipment for years, postponed critical maintenance, inadequately tested for potentially catastrophic damage, and failed to adequately protect its workers from significant risk of injury and death.
“This explosion and the deaths of these men and women would never have occurred had Tesoro tested their equipment in a manner consistent with standard industry practices, their own policies, and state regulations,” said L&I Director Judy Schurke.
L&I said that the fatal explosion occurred because the heat exchangers that receive a highly flammable byproduct of the refining process called Naptha were nearly 40 years old and in poor condition, as lab tests revealed.
“In addition, they were subjected to extreme heat and pressure, wide temperature and pressure swings, extensive chemical exposure and a near doubling of production over the years,” L&I officials said. “These are all stresses that can damage this equipment, including causing cracking.”
“The equipment also leaked hot, volatile and flammable vapor and liquid from flanges and other connections for years, especially when starting up following a shutdown,” L&I authorities said. “Tesoro’s repair efforts, including clamps, were ineffective and when they could not correct the problem, workers had to disperse the flammable vapors with long tubes called ‘steam lances’ in an effort to prevent ignition. Employees did this work in hard hats, gloves, goggles, and basic flame-resistant coveralls, which were inadequate protection for the hazards they faced.”
“If Tesoro had tested their equipment appropriately and had followed their other safety requirements, we believe that they would have found the cracks that caused this explosion and, either by replacing the equipment or repairing it, prevented this from happening,” said Dr. Michael Silverstein, assistant director, Division of Occupational Safety and Health.
Other violations L&I cited Tesoro for included failure to properly inspect equipment, failure to test for cracks and other defects in equipment prone to damage from thermal fatigue, chemical exposure, failure to implement a corrosion awareness and management program, failure to repair equipment, failure to maintain proper start-up procedures for the heat exchangers, failure to properly train workers responsible for operating the heat exchangers, failure to properly train fire brigade members, and failure to designate a single incident commander for emergency communications.