Sen. Tammy Baldwin, D-Wis., joined by senators from Minnesota and New Jersey, is calling for the U.S. Environmental Protection Agency to review the continued use of hydrogen fluoride in the refinery process.

Sens. Amy Klobuchar and Tina Smith, DFL-Minn., and Sens. Cory Booker and Robert Menendez, D-N.J., also signed the letter addressed to EPA Administrator Andrew Wheeler.

The senators are calling on the EPA to re-evaluate the adequacy of risk management plans to protect refinery workers and nearby communities for refineries in the nation that still use HF.

“In the past four years, three of the 48 refineries in the United States that still use HF have experienced severe malfunctions that could have resulted in catastrophic releases of the chemical,” the senators wrote to Wheeler. “All of there facilities where these incidents occurred had EPA-approved risk management plans, and yet they still came unacceptably close to equipment failures that could have released HF, devastating plant workers and neighboring communities. For example, at the Husky Refinery in Superior … debris released in an explosion on April, 26, 2018 punctured a structure just feet away from a tank of HF.”

In addition to a review of risk management plans, the senators are asking the EPA to review the use of HF, in light of alternatives, provide safety information if its use is be continued.

“In many cases, including the Husky Refinery … people living near the refinery are totally unaware of the presence of such a hazardous chemical in their community,” Baldwin wrote in the letter dated July 19.