CSB asks EPA to update HF study in wakes of refinery fires

The US Chemical Safety Board called on the US Environmental Protection Agency to review its existing hydrofluoric acid (HF) study to determine if existing regulations are effective and whether inherently safer alkylation technologies are a better option at refineries.

“In the last 4 years, the CSB has investigated two petroleum refinery incidents where an explosion elevated the threat of a possible release of HF or modified hydrofluoric acid (MHF),” CSB Board Member and Designated Interim Executive Kristen M. Kulinowski said in an Apr. 23 letter to EPA Administrator Andrew H. Wheeler.

“In both investigations, the CSB conducted a public hearing in which members of the surrounding communities indicated great concern about the adequacy of the risk management strategies for the use of HF and the effectiveness of community notification procedures in the event of a catastrophic release,” she noted.

The letter specifically mentioned a Feb. 18, 2015, accident at the former ExxonMobil Corp. refinery in Torrance, Calif., when an electrostatic precipitator exploded during maintenance activities, and an Apr. 26, 2018, explosion and fire at Superior Refinery Co. LLC’s plant, known as the Husky Refinery, in Superior, Wis., which injured 36 people, including 11 refinery and contract workers.

At a Jan. 30, 2016, public meeting, members of the Torrance community expressed their concerns about MHF’s presence in their community and asked if there was a safer alternative, Kulinowski said. During a Dec. 12, 2018, public town hall which CSB held in Superior, “concerned citizens expressed their desire to see HF eliminated from the Husky Refinery and the fear they experience of a possible HF release,” she continued.

Congress directed EPA to study HF in 1990 to identify potential hazards posed to the public and the environment, Kulinowski said. In a report which EPA delivered to Congress in 1993, EPA noted there were more than 500 facilities in the US which used HF, including 62 refineries, and an accidental release of HF could travel significant distances downwind as a dense vapor or aerosol cloud, posing a possibly significant threat to the public and severe consequences, she indicated.

“While we understand the anxiety and concerns the presence of HF and MHF at the Torrance and Husky refineries causes residents of these local communities, the CSB does not have the statutory authority to prevent the use of HF or MHF, or order the use of any other alternatives at these refineries,” Kulinowski told Wheeler.

“It is our understanding that new alkylation technologies are being developed, which may have inherent advantages over the use of HF at US refineries. These include a solid-state technology and an ionic liquid technology, both of which are currently being planned to replace existing HF alkylation units at least two US refineries,” she continued.

CSB is asking EPA to initiate a review and update its 1993 study to determine whether these refineries’ risk management plans are sufficient to prevent catastrophic releases, as well as whether commercially viable, inherently safer alkylation technologies are available, Kulinowski said in her letter.