Emeryville, CA – The U.S. Chemical Safety Board (CSB) has released its final report into multiple sulfuric acid releases that occurred in 2014 at the Tesoro Refinery in Martinez, CA. The report includes key process safety findings related to safety culture, safety indicators, and the continued need for a proactive regulator to conduct preventive inspections.
On February 12, 2014, an incident occurred at the Tesoro Refinery in Martinez, which burned two workers and released an estimated 84,000 pounds of sulfuric acid. Less than a month later, on March 10, 2014, sulfuric acid sprayed and burned two contract workers during the removal of piping. Both incidents occurred in the refinery’s alkylation unit – where high-octane blending components are produced for gasoline.
The CSB’s case study examines the Tesoro Martinez Refinery through the evaluation of previous incidents, worker statements, gaps in safety standards, deviations from established procedures and practices, and past efforts to assess and strengthen site safety culture.
The investigation found a number of safety culture concerns at the refinery, such as:
- Characterization of the February 2014 incident as a minor injury while the incident should have been classified as the most serious type of process safety incident under industry guidelines;
- Exposure of alkylation unit workers to hazardous materials including vapors, acids, and corrosives;
- Removal of safer sulfuric acid sampling systems from service and reliance on inadequate temporary alkylation unit equipment;
- Failure to provide alkylation unit workers with necessary protective equipment;
- Existence of site-specific safety policies that were less protective than corporate policies and established industry good practice;
- Failure to develop an action plan to address concerns identified in a 2007 safety culture survey;
- Withdrawal from key national safety programs that workers believed were effective; and
- Perceived pressure on alkylation unit workers to expedite training and reduce cost.
Following recent CSB investigations into other accidents at petroleum refineries such as the Chevron Refinery in Richmond, California, and the Tesoro Refinery in Anacortes, Washington, the CSB recommended changes to strengthen refinery regulations in California and Washington.
The state of California has issued a draft refinery process safety management standard containing more rigorous safety regulations for the oversight of petroleum refineries, and the CSB is encouraged by these proactive changes to improve safety for workers and communities.
The CSB’s case study underscores the need for the proposed refinery safety reforms as well as individual refineries to continually assess and improve their process safety programs.