A Denka Co. subsidiary has told a U.S. court that alleged toxic air pollution from its southern Louisiana chemical plant does not warrant emergency action by the U.S. Environmental Protection Agency, claiming the emissions do not pose an imminent cancer threat to the nearby community.

The Japanese company on Monday said the EPA overstepped its authority when it sought rapid reductions of carcinogenic chloroprene emissions at the plant under a little-used provision of the Clean Air Act intended for emergencies. Non-emergency provisions of that law are available to address concerns at the plant in St. John the Baptist Parish, the company said in a motion for summary judgment filing.

The EPA’s 2023 lawsuit against the subsidiary, Denka Performance Elastomer, said air monitoring had consistently shown chloroprene near the plant as high as 15 times the recommended concentration deemed safe over a lifetime of exposure.

The EPA said the facility, a former DuPont plant purchased by Denka in 2015, poses an “imminent and substantial endangerment to public health and welfare" in the nearby community, which is predominantly Black.