A final report released in July by the U.S. Chemical Safety Board (CSB) discusses key process safety findings from the agency’s investigation into two sulfuric acid releases that occurred in 2014 at the Tesoro Refinery in Martinez, Calif. CSB’s report, which provides a summary of the investigation and focuses on safety culture and safety indicators, states that “a weak process safety culture created conditions conducive to the recurrence of sulfuric acid incidents that caused worker injuries over several years.”

The first incident at the Tesoro Martinez Refinery on Feb. 12, 2014, burned two workers and released an estimated 84,000 pounds of sulfuric acid. The second incident occurred less than a month later on March 10, when sulfuric acid sprayed and burned two contract workers during the removal of piping in the refinery’s alkylation unit, in which high-octane blending components are produced for gasoline. During its investigation into the incidents at Tesoro Martinez Refinery, CSB evaluated previous incidents, worker statements, gaps in safety standards, deviations from established procedures and practices, and past efforts to assess and strengthen site safety culture.

CSB’s report identifies several safety culture concerns at the refinery, including minimization of the seriousness of the Feb. 12, 2014, process safety incident; failure to provide alkylation unit workers with necessary and functional personal protective equipment; and ineffective incorporation and communication of lessons learned from previous safety incidents.

“Simply identifying safety culture deficiencies, however, is not sufficient,” CSB concludes. “Effective continual improvement programs are necessary to address safety culture weaknesses in order to prevent significant accidents, worker injuries, and the potential for community impact.”

Further details of CSB’s investigation and its recommendations are available in the ().