City of Superior and Husky Energy officials said they are examining whether to continue using hydrogen fluoride at Superior's Husky Refinery after Thursday's asphalt fire burned within 200 feet of the tank containing the dangerous gas.
But the officials stopped short of making a commitment during a press conference Monday at the refinery.
"The only reason I'm not saying yes right now is because I have more to learn about hydrofluoric acid," Superior Mayor Jim Paine told the News Tribune after the press conference.
Breathing in hydrogen fluoride at high levels, or in combination with skin contact, can cause death from an irregular heartbeat or from fluid buildup in the lungs. The gas can also cause blindness by rapid destruction of the corneas. Evacuations Thursday were made with hydrogen fluoride in mind and officials considered a potential release of the chemical the worst-case scenario.
When asked if he would urge Husky to use a less-dangerous alternative to hydrogen fluoride, like sulfuric acid, Paine said it was "absolutely a possibility" but wanted to learn more about the refinery process before taking an official stance.
The Superior refinery is one of about 50 nationally that still uses hydrogen fluoride to process high-octane gasoline.
Kollin Schade, the refinery's manager, said the company will examine whether to continue storing hydrogen fluoride at the facility, but the investigation must be completed first.
"We will be looking at all kinds of different options for the refinery configuration going forward. Right now ... our main concern is to try to understand exactly what happened here," Schade said during the press conference.
"If you look at a refinery, technology is always improving ... we are always going to be examining new technology and what's available out there. That's an ongoing basis," Schade said.
The refinery can handle about 78,000 pounds of hydrogen fluoride, according to federal EPA records from 2012, but it contained about 15,000 pounds of the chemical at the time of the fire. The fire never reached the hydrogen fluoride, and on Friday Schade said that tank was "not compromised whatsoever" by the explosions or fire.
Paine said the city will hold Husky accountable throughout the investigation and cleanup.
"We expect Husky to be a great corporate citizen," Paine said during the news conference.
However, both the mayor and Husky officials said it is too early to tell who will foot the bill if any cleanup is needed in the surrounding area.
The timeline of the investigation and refinery repair is unclear.
"It's going to take a while," Schade said.
Husky to repair, restart refinery
Prior to the press conference, Wisconsin Gov. Scott Walker walked along 24th Avenue East with city and refinery officials to see the refinery damage firsthand.
During the press conference, Walker told reporters that Robert Peabody, Husky's president and CEO, remained committed to operating the refinery in Superior.
"They are going to be here, which is good because on a day-in and day-out basis, there's a lot of families that depend on the good-paying, family-supporting jobs and careers available here," Walker said.