PROCESS SAFETY MANAGEMENT
CSB: Multiple Safety Deficiencies Caused Refinery Explosion, Near Miss
Multiple process safety management deficiencies contributed to the February 2015 explosion, and serious near miss, at the ExxonMobil Refinery in Torrance, Calif., according to preliminary findings released by the U.S. Chemical Safety Board (CSB) on Jan. 13. The blast, which was caused by an accumulation of hydrocarbons inside of the refinery’s electrostatic precipitator (ESP), injured two workers. CSB investigators found that ExxonMobil failed to conduct a management of change review before implementing an outdated “variance,” a document required for temporary deviances from normal operating procedures, when bringing a piece of equipment back online. ExxonMobil also failed to perform adequate process hazard analyses, which could have targeted better safeguards against the flow of hydrocarbons. “Although our investigation found two different process hazard analyses that considered a combustible mixture igniting in the electrostatic precipitator, no effective safeguards were implemented at the refinery to mitigate this threat,” said Mark Wingard, CSB’s investigator-in-charge. The investigation also revealed that a large piece of debris thrown during the explosion nearly missed a tank that contained tens of thousands of pounds of modified hydrofluoric acid (HF). “Had flying debris ruptured the tank of modified HF, this accident could have been far worse,” CSB Chairperson Vanessa Allen Sutherland stated. “After HF acid vaporizes it condenses into small droplets that form a dense low-lying cloud that will travel along the ground for several miles and can cause severe damage to the respiratory system, skin, and bones of those who are exposed, potentially resulting in death.” According to CSB, 333,000 residents live within a three-mile radius of the refinery. Read more in CSB’s press release.