By Jaxon Van Derbeken and Henry K. Lee
San Francisco Chronicle
MARTINEZ, Calif. — Two contractors doing maintenance work at Tesoro Corp.’s refinery near Martinez, Calif., suffered burns Monday when they were splashed with sulfuric acid, an accident that occurred in the same processing unit where two employees were burned by acid last month, officials said.
The sulfuric acid spilled on the two contractors’ necks at 10:50 a.m. (Pacific time) at Tesoro’s Golden Eagle refinery in Northern California, said Maria Duazo, a Contra Costa County hazardous materials specialist.
Other workers with knowledge of what happened said the two had been splashed with acid while working on a pipeline, though the circumstances were not immediately known. The men initially were protected from injury by their protective suits, but some acid remained on the garments and drained onto their necks after the men took decontamination showers, the workers said.
Peter Melton, spokesman for Cal/OSHA, the state’s worker safety regulatory agency, said the contractors had been working on pipes in the same unit where two Tesoro employees were burned by acid Feb. 12. The pipes carry sulfuric acid to be mixed with butylene to boost octane levels in gasoline.
State inspectors were being dispatched to the plant Monday, Melton said.
Tina Barbee, spokeswoman for the San Antonio-based independent oil refiner, said in an email that the workers were conducting planned maintenance and were wearing “full protective safety equipment,” decontaminated in a shower and transported to a local hospital.
“One of the contractors has been cleared and released. The other remains at the facility for observation,” she said.
Barbee said “all requisite regulatory agencies have been notified,” and that the incident “is under investigation and unrelated to a chemical release that occurred on Feb. 12.”
In the Feb. 12 accident, two workers who weren’t wearing proper protective gear were sprayed with sulfuric acid when a pipe broke. They were treated for first- and second-degree facial burns at a Sacramento hospital and released the same day.
Cal/OSHA ordered Tesoro’s octane unit shut down on Feb. 18 after finding several possible safety violations. In justifying the shutdown, investigators said workers “feared” dealing with the sulfuric acid and that a pipe had broken apart in workers’ hands days after the spill.
After the company completed retraining and safety checks, the state agency allowed Tesoro to reopen the unit on Feb. 28, Cal/OSHA spokeswoman Erika Monterroza said.
The Feb. 12 incident was also scrutinized by the U.S. Chemical Safety Board, which investigates the causes of accidents at chemical plants. Tesoro allowed federal investigators into the refinery the day after the workers were burned, but barred them from future visits.
The safety board wrote a letter in protest and, after federal investigators subpoenaed Tesoro for documents, the company allowed inspectors onto the refinery grounds again earlier this month.
The board’s investigative team left the Bay Area last week, but late Monday, managing director Daniel Horowitz said the board’s lead investigator, Dan Tillema, was headed to Tesoro’s plant.
In an emailed statement Monday, Horowitz said that although the safety board has “obtained some cooperation from Tesoro,” the company hasn’t provided some key documents the safety board sought, including a recent survey of Tesoro’s safety culture.
“In addition, evidence at the site has not been preserved,” Horowitz said. “One eye-opening document that the team did obtain is a Tesoro engineering calculation estimating that 84,000 pounds of sulfuric acid were released in the Feb. 12 incident — hardly the minor release that Tesoro has been describing to the public.”
San Antonio Express-News Reporter Vicki Vaughan contributed.