Feds: Botched safety reviews contributed to ExxonMobil refinery explosion
By Nick Green, Daily Breeze
Management failures to review an outdated procedure and inadequate hazard analyses were among a series of deficiencies that led to the February explosion at ExxonMobil’s Torrance refinery, an independent federal agency has concluded.
The U.S. Chemical Safety Board also reported that a piece of machinery that contributed to the blast had operated since 2010 without a maintenance overhaul, forcing some critical pieces of safety and other equipment to be in use beyond their “safe operating life.”
The agency, which is in charge of investigating serious chemical accidents, announced preliminary findings Tuesday in the ongoing probe of the “root cause” of the blast that injured two workers and belched industrial debris up to a mile away. Those findings were revealed at a Wednesday news conference in Redondo Beach.
Investigators for the agency said ExxonMobil’s missteps bore similarities to the Aug. 6, 2012, fire at the Chevron refinery in Richmond that sent more than 15,000 residents of the surrounding area to hospitals. But in this case, the force of the blast caused large pieces of debris to hit scaffolding surrounding a tank containing “tens of thousands of pounds” of potentially deadly hydrofluoric acid. The “near miss” could have caused a catastrophic release of the chemical into the surrounding neighborhood, the agency said.
“Had flying debris ruptured the tank of modified HF, this accident could have been far worse,” CSB Chairwoman Vanessa Allen Sutherland said in a statement. “Hydrofluoric acid can pose a severe hazard to the population and environment if a release occurs,” she added. “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.” There are 333,000 residents, 71 schools and eight hospitals within a three-mile radius of the sprawling refinery, the agency said.
“One or two” lasers designed to detect accidental HF releases were rendered inoperable by the force of the blast, said Mark Wingard, investigator-in-charge. “Some of the mitigation systems were compromised,” he said.
ExxonMobil on Wednesday disputed the threat to the community as described by CSB officials and said it had taken unspecified “corrective actions” to prevent a reoccurrence.
“We found there was no evidence that suggested the Feb. 18 incident posed any risk of harm from the modified hydrofluoric acid,” spokeswoman Gesuina Paras said via email. “There was no damage to (gasoline) process equipment or loss of containment.”
CSB investigators contend they have faced “a lack of cooperation” from ExxonMobil to comply with requests for information about the near miss. To date, the agency has “no or incomplete responses” to 49 percent of its subpoena requests, Sutherland said. South Bay Rep. Ted Lieu said Tuesday he found the company’s lack of disclosure in “intentionally obstructing the investigation troubling.” The agency is asking the Department of Justice to intervene in an effort to compel the company to respond. But Sutherland said Wednesday that ExxonMobil is asserting that the agency lacks jurisdiction to even investigate the “near miss.”
Nevertheless, ExxonMobil said Wednesday that the company “stands on its record of good faith compliance with all agencies.”
“Since February 2015, ExxonMobil has provided more than 340,000 pages of documents, images, and our workers participated in nearly 156 witness interviews with various agencies — including 136,000 pages and 67 interviews for the Chemical Safety Board,” Paras wrote.
The hydrofluoric acid used at the plant supposedly is modified with an additive to make it safer, but Lieu said CSB officials have expressed concerns to him about its efficacy. At the refinery, the additive as well as temperature and pressure controls are supposed to render inert 40 percent of any acid spill, Wingard said. That means, in theory, the HF vapor would form a liquid that is more easily contained and poses less of a threat than a gas.
“Their response was basically ‘we don’t know if this works,’ ” Lieu said. “There has been no non-industry-sponsored tests that show MHF would drop to the ground.”
Wingard said Wednesday that because of ExxonMobil’s stalling, the safety board didn’t know how much HF is routinely stored at the refinery, how much was in the vessel that was almost hit by debris or what percentage of additive was in use at the refinery. Sutherland said Wednesday the agency is considering taking a closer look at a possible ban of HF, which is used in about 50 of the nation’s oil refineries. The uncertainties surrounding modified HF have prompted Lieu and fellow South Bay Rep. Maxine Waters to prepare legislation that could ban its use, Lieu said.
In a statement released Wednesday, ExxonMobil responded that any review of HF use should not “unfairly single out the refining sector, which represents just 5 percent of the hydrofluoric acid used in California.”
In addition, Lieu said it appears ExxonMobil may have significantly underestimated the worst-case scenario for an accidental release of HF. The company has estimated that an accidental release of just 2 percent of the HF stored at the plant would put 250,000 people at risk, the first-term congressman said.
“I don’t know how anyone can predict how much MHF would be released,” Lieu said. “It certainly could be more than 2 percent.”
The U.S. Environmental Protection Agency announced in December that it would investigate whether ExxonMobil understated the public health risk associated with an accidental release of HF. Companies are required to comply with a risk management plan outlining a major disaster scenario.
An 80,000-pound piece of equipment reportedly was sent flying through the air by the force of the explosion, narrowly missing the vessel containing HF. Jim Tarr, president of Rolling Hills Estates-based Stone Lions Environmental Corp., which evaluates refinery emissions, said he would like to see an air dispersion modeling study conducted to evaluate the scope of the ensuing disaster had the vessel ruptured, given the air direction and wind speed on the day of the blast.
“Then everybody can understand the kind of threat they’re living next door to and what the opportunity for public harm really and truly is,” Tarr said.
CSB officials said Wednesday that ExxonMobil operators tried unsuccessfully for five days to bring under control “violent” vibrations in a piece of energy conservation equipment known as an “expander” that contributed to the blast. The CSB said ExxonMobil failed to conduct a “management of change review” to bring a piece of inoperable equipment back into service. The review would have looked at a variance — a written temporary deviation from normal operating procedures — that was created in 2012 to address problems with the equipment.
That review did not occur, even though refinery conditions had changed over the previous three years, the agency said. In addition, “inadequate process hazard analyses” failed to identify more effective safeguards that could have reduced any explosive threat.
The agency concluded that steam traveling through an undetected leaking valve caused the explosion. Hourly workers knew the valve could not withstand the pressure, but were not consulted by ExxonMobil management, safety board officials said.
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