A coalition of environmental and public health groups, among other activists, are suing the federal government, attempting to force the EPA under President Donald Trump to enforce tight national soot standards slapped in place under former President Joe Biden, but which business groups and others warn would cripple the U.S. economy.
The coalition of 17 organizations filed their lawsuit on April 13 against the U.S. Environmental Protection Agency in San Francisco federal court.
The lawsuit takes aim purportedly at the Trump administration’s refusal to continue the work begun under the Biden administration to enforce the so-called 2024 National Ambient Air Quality Standard (NAAQS) for “particulate matter air pollution,” commonly referred to as soot.
The new standards were enacted in the waning days of the Biden administration, amid a slew of executive and bureaucratic actions in 2024 designed to ensconce Democratic policy priorities and initiatives, as the election of Donald Trump to a second term became increasingly likely.
Since Trump took office in January 2025, his administration has repeatedly sought to end or reverse many of those Biden executive initiatives.
However, those attempts by the president to enact his administration’s policies have repeatedly been challenged in court by Democrats and other left-wing groups, often asserting Trump has no choice but to execute the progressive rules, regulations and policies put in place by his predecessor.
Trump has pushed back on those legal challenges, with mixed results.
In 2024, the Biden EPA notably substantially tightened the emission limits for soot, dropping the allowed limits from the longstanding standard of 12 micrograms per cubic meter of air to just 9 mcg.
Environmental and public health groups hailed the decision, asserting it would generate billions of dollars in net health benefits over the coming years, claiming it would sharply reduce asthma in children and prevent 4,500 premature deaths.
They asserted it would particularly benefit black and Hispanic Americans living in and around industrial zones which typically have higher rates of air pollution from smokestacks, power plants, highways, railroads, trucking and shipping terminals, and other potential sources of soot.
Business groups, however, said the rules are based on questionable science and will hammer the U.S. economy, likely proving especially harmful to those same economically challenged communities the EPA asserted they are trying to help.
They argued the new standards would block new economic development in as many as 30% of U.S. counties that would be out of compliance.
The attorneys general of 25 states agreed.
Those states and business groups, including the U.S. Chamber of Commerce and National Association of Manufacturers, filed suits challenging the new soot rules.
“The EPA’s new rule has more to do with advancing President (Joe) Biden’s radical green agenda than protecting … health or the environment,” Kentucky Attorney General Russell Coleman said at the time the lawsuit challenging the new rules was filed.
In 2025, the Trump administration abandoned the federal government’s defense of those rules, instead filing a motion siding with the challengers.
That move generated shock and outrage from supporters of the new rules.
Now, they have lodged a separate lawsuit seeking a court order that the EPA under Trump is obligated to enforce the Biden soot standards, even if the current EPA no longer believes the regulations are scientifically or legally sound.
The activist plaintiffs assert the EPA has no discretion under the law on how to enforce the rules, and must simply enforce them.
In a statement announcing the lawsuit, the coalition made plain its desire to force the Trump administration to abide by the Biden-era rules: “The EPA’s refusal to take even basic steps to drive compliance with the 2024 soot standard leaves one of the most dangerous forms of air pollution largely unchecked, putting the health of Americans at risk,” they said.
“Doctors and scientists who treat patients and study air pollution have made overwhelmingly clear that soot pollution kills and sickens people. Delaying compliance and enforcement of the standard is a choice the Trump administration is making to allow preventable health harms to worsen every day.”
The Trump administration has not yet responded to the lawsuit in court.
Plaintiffs in the action include: the American Lung Association, Sierra Club, Natural Resources Defense Council, American Public Health Association, American Thoracic Society, Center for Biological Diversity, Citizens for Pennsylvania’s Future, Clean Air Council, CleanAIRE NC, Conservation Law Foundation, Environmental Defense Fund, Georgia Interfaith Power & Light, Michigan Environmental Council, and the Northeast Ohio Community Resilience Centre, among others.
The plaintiffs are represented by attorneys from the Natural Resources Defense Council, EarthJustice, and the Southern Environmental Law Center.
