CSB issues recommendations after Louisiana refinery fire investigation

Washington – The Chemical Safety Board released a set of recommendations Sept. 18 after its investigation into last year’s ExxonMobil refinery fire, which severely burned four workers in Baton Rouge, LA.

The fire occurred Nov. 22 during maintenance in the refinery’s sulfuric acid alkylation unit when an older, “ill-advised” design on a support bracket led to the release of about 2,000 pounds of pressurized isobutane, a hydrocarbon gas.

Two workers were attempting to get a spare isobutane pump into service but could not open an inlet plug valve because of a malfunctioning gearbox. They removed the gearbox to turn the valve stem with a pipe wrench, but the four bolts on the support bracket also secured a critical pressure-containment part known as a top-cap, which came apart and released the vapor cloud.

“Our investigation found that these accepted practices were conducted without appropriate safety hazard analysis, needlessly injuring these workers,” CSB Chairperson Vanessa A. Sutherland said in a press release. “It is important to remember that good safety practices are good maintenance practices and good business practices.”

CSB’s safety bulletin states that only 15 out of about 500 plug valves used the flawed support bracket design, which was more than 30 years old. The agency pointed to the refinery’s “failure to identify and address the older model plug valve design and gearbox reliability issues” as among its deficiencies.

The bulletin lists the following recommendations for chemical manufacturing facilities:

• Use the Hierarchy of Controls to alleviate hazards and look at “human factors associated with operational difficulties that exist in your machinery and other equipment.”
• Create accurate and detailed procedures for potentially dangerous work, including removing inoperable gearboxes.
• Supply training – focused on equipment and processes – to ensure workers can perform their duties safely, boost hazard awareness and prevent incidents.

CSB released an animated video on the refinery fire in July.