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Refinery fostered weak safety, Chemical Safety Board says

Report probes sulfuric acid accidents that injured workers

by Jeff Johnson, special to C&EN
August 4, 2016 | APPEARED IN VOLUME 94, ISSUE 32

Credit: CSB
A piping failure during a maintenance operation to replace a sulfuric acid sampling system injured workers at the Tesoro Refinery in Martinez, Calif.
Credit: CSB
A piping failure during a maintenance operation to replace a sulfuric acid sampling system injured workers at the Tesoro Refinery in Martinez, Calif.

The Tesoro refinery in Martinez, Calif., for years ignored safety problems and fostered a weak safety culture, the U.S. Chemical Safety Board says in a report released on Aug. 2.

Board officials urged Tesoro and other refiners to elevate the importance of process safety and encouraged state and local regulators to frequently conduct preventive safety inspections of the facility.

Triggering CSB’s report and investigation were incidents in February and March 2014 at the facility’s alkylation unit, which carries out a process common at U.S. refineries. Tesoro’s unit uses sulfuric acid as a catalyst to reformulate low-value hydrocarbons, such as propane and butane, to produce a premium, high-octane gasoline blend stock.

The first of the two accidents was the result of a piping failure that released some 38,000 kg of sulfuric acid over two hours and burned two employees. Tesoro initially characterized the accident as minor and refused to allow CSB to investigate. In the second incident a month later, two contract workers were sprayed and burned with sulfuric acid at the same unit.

The two incidents followed 13 similar sulfuric acid accidents at the facility since 2010, CSB says. It suggests the company failed to learn from past mistakes and allowed accidents to continue.

The second incident, CSB notes, had similarities to a 1999 incident at the refinery in which four workers were killed.

Much of CSB’s report focuses on the February 2014 accident which occurred in piping for the plant’s sulfuric acid sampling system. Tesoro had purchased and intended to install a new, closed-loop, so-called inherently safer acid sampling system that is similar to those used at other California refineries.

However, the company claimed the system was unreliable, CSB says, and never installed it. Instead Tesoro slightly upgraded its existing sampling system, which requires workers who draw samples to wear personal protective gear to counter the expected release of sulfuric acid vapors.

Tesoro officials would not comment on the specific accident or decision not to install inherently safer technology. They, however, cited unspecified “inaccuracies” in CSB’s report.



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Cliff Tebeau, PhD (August 10, 2016 9:09 AM)
There is absolutely NO excuse for this irresponsible Corporate behavior toward their employee Safety. CSB, thanks your report.
Ken Nightlinger (August 10, 2016 6:10 PM)
Repeated problems of even a similar nature do show a pattern. Problem is many corporate decisions are now overridden by corporate bean counters/CFO's, so needed changes never happen. This simple bean counting mentality never considers the total costs such as: damage to other equipment, loss of production, disruption of the country's economic supply chain, insurance costs we all pay in the final product prices, investigation costs, csb expenses, court and legal costs, the trauma of the survivors and the families of lost loved ones and disfigured family members, burdens on the emergency response and medical community. Imminent lawsuits filed and usually settled out of court for undisclosed terms, with gag orders.

Thus the substantially lacking corporate safety culture perpetuates, until the company decides to change and strictly operate based upon providing a work environment that they would place their own children into, day after day.

Respectfully submitted
Ken Nightlinger

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