CSB Board Members Add Preventive Maintenance to Most Wanted Safety Improvement Program


Washington, D.C., July 15, 2016 - Today the U.S. Chemical Safety Board (CSB) formally announced that “Preventive Maintenance” has been included as a “Most Wanted Safety Improvement,” stating that inadequate mechanical integrity programs, delayed or deferred preventive maintenance, and the aging infrastructure of equipment at chemical facilities have been a recurring root cause of incidents investigated by the CSB.

The CSB has investigated 11 incidents and currently has 21 open recommendations aimed at addressing gaps at a number of levels, including: facility, corporate, regulatory programs and industry standards. The intent of the board’s recommendations is to promptly identify equipment upgrades, ensure that replacements are not delayed and equipment is not made to operate longer than it should.

CSB Chairperson Vanessa Allen Sutherland, who will serve as the champion for this issue with support from the board members – said, “It is imperative that facilities institute a comprehensive preventive maintenance schedule for their equipment. Too many CSB investigations have highlighted a lack of timely inspections and scheduling of proper maintenance.”

Several of the 11 investigations identified occurred at refineries.

The CSB’s investigation into the catastrophic failure of a forty-year-old heat exchanger at the Tesoro Refinery in Anacortes, WA, found that the fatal explosion and fire was caused by damage to the heat exchanger, a mechanism known as “high temperature hydrogen attack,” or HTHA, which severely cracked and weakened carbon steel tubing lead to a rupture. Tesoro used an inspection strategy that relied on design operating conditions rather than verifying actual operating parameters, and the CSB determined that inspections for this type of damage are unreliable, as the microscopic cracks can be localized and difficult to identify.

Another refinery investigation in which a lack of preventive maintenance was a root cause is the 2012 accident at the Chevron Refinery in Richmond, California, where a catastrophic pipe failure led to a massive fire. Testing determined that the pipe failed due to thinning caused by sulfidation corrosion, a common damage mechanism in refineriesThe CSB’s investigation of the incident found that Chevron repeatedly failed over a ten-year period to upgrade piping in its crude oil processing unit, which was extremely corroded and ultimately ruptured on August 6, 2012.  The CSB found a failure by Chevron to identify and evaluate damage mechanism hazards, which if acted upon, would likely have identified the possibility of a catastrophic sulfidation corrosion-related piping failure.

The CSB is an independent federal agency charged with investigating significant chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.

The Board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA. Visit our website, www.csb.gov.

For more information, contact Communications Manager Hillary Cohen, cell 202-446-8094 or Sandy Gilmour, Public Affairs, cell 202-251-5496.

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