More than a year after an explosion and fire at the Husky Energy oil refinery in neighboring Superior, Wis., Duluth Mayor Emily Larson is calling for a federal agency to re-examine hazards associated with the industry’s use of hydrogen fluoride.

The Duluth City Council plans to vote on a resolution Monday to formally request that the Environmental Protection Agency (EPA) “take action to prevent future catastrophic disasters” related to the use of the highly toxic chemical in refineries.

“My biggest hope is that no other community has to experience an explosion or a near-miss or a catastrophe because of a choice on the part of a refinery to continue to use that material,” Larson said Friday.

If passed, the Duluth resolution would not be the first plea for action from the federal agency. The U.S. Chemical Safety Board, an independent agency that investigates chemical accidents and makes recommendations to companies and regulatory bodies, sent a letter to the EPA in April saying it “strongly encourages” it to review whether refineries’ risk-management plans are sufficient to prevent “catastrophic releases” of hydrogen fluoride.

An EPA spokesperson said Friday the agency is still working on a response to the board’s request. It last studied the hazards of hydrogen fluoride in 1993 at Congress’ request.

The Chemical Safety Board raised alarms following its investigations of the Superior explosion and a similar incident at a former Exxon Mobil refinery in Torrance, Calif., in 2015. In late June, two months after the board sent its letter, an explosion and fire at a refinery in Philadelphia renewed concerns about the potential dangers of hydrogen fluoride. No chemical was released at any of the three incidents.

The explosion at the Superior refinery in April 2018 hurled shrapnel into a steel tank full of asphalt, spilling more than 15,000 barrels and eventually causing a major fire that created a cloud of smoke and ash far across northwestern Wisconsin. Superior officials evacuated most of the city for fear the blaze would cause a nearby tank of hydrogen fluoride at the plant to leak.

Hydrogen fluoride is a fast-acting acid that causes burns and can kill. The chemical can permanently damage eyes, skin, nose, throat, bones and the respiratory system, according to a 2013 report issued by the United Steelworkers union, which represents many refinery workers.

Hydrofluoric acid, which is hydrogen fluoride dissolved in water, is used as a catalyst to boost octane in gasoline in about half the nation’s refineries.

Accidents involving the chemical are rare, but the EPA conducts calculations predicting worst-case scenarios, many of which are catastrophic. In the Twin Ports, a massive hydrogen fluoride leak would put 180,000 people at risk, according to agency records.

Husky Energy announced in April that it would continue to use hydrogen fluoride at the Superior refinery after it is rebuilt, a $400 million project expected to begin this fall with the goal of allowing partial operations to resume in late 2020.

Mel Duvall, spokesperson for the Calgary-based company, said in an e-mail Friday that after a “rigorous evaluation,” Husky concluded alternatives to hydrogen fluoride “were not commercially viable or introduced significant risks for the Superior refinery.

“We remain committed to the future of the refinery, our employees and the community and want to ensure it will continue to contribute to the economy of the region for decades to come,” said Duvall, who added that the company is also installing new safety features as it rebuilds the refinery.

Larson argued it’s not enough and said the company’s response to last year’s explosion was unsatisfactory. She wrote a letter to Husky Energy in April asking it to prove that using hydrogen fluoride is the safest choice and “not a choice of cost or systems efficiency.”

Husky responded by citing the planned safety enhancements and noting that its system prevented a chemical leak during the 2018 explosion. It also said that the new plant will be more energy efficient and “in full compliance with government regulations.”

“So, I want to change the government regulations,” Larson said Friday.

The mayor, who is up for re-election in November, said she is aware of her limitations. She hopes the resolution will help spur change to federal policy and licensing policy surrounding the usage of hydrogen fluoride. The city of Superior does not plan to introduce a similar measure, but Mayor Jim Paine said in a statement that he supports Larson’s efforts to put pressure on the EPA.

Ultimately, Larson said she hopes policy changes will eventually take away the choice refineries have to use hydrogen fluoride.

“Because that choice,” she said, “comes with tremendous risk for health and safety.”