In a unanimous decision, a three-judge panel of the U.S. Ninth Circuit Court of Appeals ruled Monday that Exxon Mobil Oil Corp. must produce information to the U.S. Chemical Safety Board (CSB) related to a tank filled with hydrofluoric acid at the site of a 2015 oil refinery explosion in Torrance, California.

The decision reverses a lower Court ruling that the information was not sufficiently relevant to the CSB’s investigation.

Debris landed near hazmat

The incident occurred on Feb. 18, when an explosion in the fluid catalytic cracking (FCC) unit shook the surrounding area with the force of a 1.7 magnitude earthquake and propelled a 40-ton piece of debris about 100 feet where it landed within five feet of a tank containing thousands of gallons of modified hydrofluoric acid. Hydrofluoric acid is a highly corrosive liquid that dissolves glass. Breathing it can cause lung damage and skin contact can cause severe burns and death.

The CSB issued subpoenas for information regarding the contents of the tank, siting hazards, and related safety concerns. Exxon refused to provide this information.

Risks made subpoenas relevant

The Appeals Court agreed with the CSB’s position that the subpoenas related to the modified hydrofluoric acid tank were relevant and within the Board’s authority because “the risks of … an accidental release of modified hydrofluoric acid were among the ‘facts, conditions, and circumstances’” of the February 15, 2015, explosion:

"The Board is not limited to the “facts, conditions, and circumstances” that caused the accidental release,” said CSB Interim Executive Authority Dr. Kristen Kulinowski. “The Board should look as well to the effects and the potential harm, were a similar incident to occur.

“The presence of two tanks full of toxic chemicals on the site of the explosion, very close to where debris from that explosion landed, is among the ‘circumstances’ of the explosion."

Kulinowski said the CSB is hopeful that Exxon will cooperate and promptly provide details about the HF tanks to the agency. “With this information, the CSB will be able to complete a critical part of its investigation into the Torrance refinery explosion that has been stalled due to litigation.”

The CSB was represented by attorneys from the Environmental and Natural Resources Division of the U.S. Department of Justice. The Attorney General of California and the South Coast Air Quality Management District filed an Amicus brief with the Court in support of the CSB.

United States v. Exxon Mobil Corp., 9th Cir., No. 18-55481, 12/9/19 and is available at