A weak safety culture at the Tesoro refinery in Martinez led to four workers being injured by exposure to sulfuric acid in February and March of 2014, according to a report by the U.S. Chemical Safety Board released Tuesday.
The two incidents were part of a larger pattern of poor safety procedures at the refinery that included 15 workers being exposed to sulfuric acid in 13 separate incidents between 2010 and 2013.
CSB officials wrote in the 60-page report:
“The investigation found that a weak process safety culture created conditions conducive to the recurrence of sulfuric acid incidents that caused worker injuries over several years.”
The investigation found that Tesoro had tried to minimize the seriousness of the incident on Feb. 12, 2014, characterizing the two workers’ acid burns in the February incident as “minor” and not classifying it as a serious safety incident.
The workers suffered first- and second-degree burns and were airlifted to UC Davis Medical Center after the incident. They were released later that day.
The CSB stepped in to investigate the accident along with the state Division of Occupational Safety and Health. But in a letter released in 2014, CSB chairman Rafael Moure-Eraso complained that Tesoro was blocking the agency’s efforts to properly conduct its investigation.
Tesoro denied the allegation, but questioned whether the CSB had jurisdiction to investigate the accident. Less than a month later, on March 10, two other workers were injured by exposure to acid.
The weak safety culture went back over a decade, to before Tesoro took over the refinery, according to the CSB report. The problems were traced back to 1999, when four workers were killed and another was injured in a fire at the crude unit at the refinery, then called the Avon refinery and owned by the Tosco Corporation.
Tesoro took over the refinery in 2002, but the safety problems continued, according to the CSB. The agency found that the two 2014 incidents were just part of a pattern of numerous accidents involving exposure to acid that were tolerated without proper adjustments made to improve safety.
Among the safety problems identified in the report’s findings: workers were routinely exposed to hazardous vapors, acids and caustic chemicals, were not provided proper safety gear, and safety protocols at the site were below industry and corporate standards.
In a statement, Tesoro spokeswoman Patricia Deutsche referred to unspecified “inaccuracies” in the report, but said that Tesoro had learned from the 2014 accidents and worked closely with regulatory agencies in reviewing its safety procedures.
“The improvements made since 2014 include standardization of tubing assembly and testing, updated protective equipment and standards, upgraded sample system equipment and procedures, elevated safety communications and initiatives and improved tools and processes that enable continuous improvement.”
“We have, and continue to, share information with industry groups to ensure that others in our industry can also learn from these events. We are committed to continuing our journey toward an injury-free work place by nurturing a positive process safety culture and employing the right tools and processes.”