MADISON, Wis. (AP) -- The U.S. Chemical Safety Board wants federal environmental regulators to re-examine a 1993 study on hydrofluoric acid after an explosion at a Superior oil refinery last year.
Wisconsin Public Radio reports that the board wants the U.S. Environmental Protection Agency to review the study to determine the effectiveness of existing regulations and the viability of using safer technologies in refineries.
About a third of the nation's 150 refineries still use hydrofluoric acid to produce high octane gas.
An explosion at the Husky Energy refinery in Superior in April 2018 sent debris within 150 feet of the refinery's hydrofluoric acid tank, forcing a large part of the city to evacuate.
Husky spokesman Mel Duvall tells WPR that the refinery has installed additional protections since the blast.
