The U.S. Chemical Safety Board is calling on the U.S. Environmental Protection Agency to revisit a 1993 study on hydrofluoric acid in the wake of an explosion and series of fires at the Husky Energy oil refinery in Superior last year.
Kristen Kulinowski, the CSB's interim executive, said the agency should examine existing regulations, risk management procedures, and the feasibility of safer technologies used in the alkylation process at oil refineries.
"In the last 4 years, the CSB has investigated two refinery incidents where an explosion elevated the threat of a release of HF. Refinery workers and surrounding community residents are rightly concerned about the adequacy of the risk management for the use of hazardous chemicals like HF," said Kulinowski in a statement. "The EPA should review its 1993 HF study to ensure the health and safety of communities near petroleum refineries utilizing HF."
Congress directed the EPA to conduct the study in 1990 to pinpoint impacts to the environment and human health. Since then, an explosion at the ExxonMobil refinery in Torrance, California occurred in its fluid catalytic cracking unit in 2015, which is similar to the explosion that occurred at Husky's refinery in Superior last year. Hydrofluoric acid, which is also known as hydrogen fluoride, is a highly toxic chemical that can be hazardous to human health if released. The chemical can kill at concentrations of 30 parts per million, according to the CSB.
Fears over a potential release of the chemical prompted the evacuation of Superior residents last spring. Debris from the explosion came within 150 feet of the hydrogen fluoride tank, but Husky has said its safety systems worked and the tank was not compromised.
Around one-third of the nation’s 150 refineries still use the chemical in its refining process. The chemical is used as a catalyst in producing high octane gasoline.
More than one-third of roughly 1,600 Superior residents surveyed this winter by a local activist group said they would like to see the use of hydrogen fluoride banned in the city. Three dozen people were injured as a result of the explosion last April, according to the CSB.