Federal Judge Blocks Trump EPA’s Efforts to Attack Clean Air Waivers

Yesterday, a federal judge granted California a preliminary injunction blocking EPA’s actions targeting four Clean Air Act preemption waivers previously granted to California.

Senior U.S. District Judge Beryl Howell also denied EPA’s motion to dismiss the case.

The preliminary injunction ordered EPA to “restore the status quo” before announcing the reclassification of four clean air waivers. EPA unlawfully reclassified the waivers so Congress could attempt to repeal the waivers with an expedited process under the Congressional Review Act.

In response to the announcement, Sierra Club’s Clean Transportation for All Director Katherine García released the following statement:

“For decades, California's Clean Air Act waivers have protected public health and driven innovation in cleaner vehicles and engines. This summer, as families across the country struggled with rising costs, Trump’s EPA and congressional Republicans chose to spend their time attacking states' ability to protect residents from harmful pollution – instead of addressing the affordability crisis. The EPA's move to attack these waivers would benefit Big Oil at the expense of public health, and the court saw through it. Congress should take this ruling as a signal to abandon this unlawful scheme entirely and get to work on the real problems facing Americans.”

Background on waivers:

In June 2026, the EPA announced it was reclassifying four Clean Air Act preemption waiver orders into rules subject to Congressional Review Act. The four waivers enable California to address air pollution through the following standards:

• Greenhouse gas (GHG) emission standards for passenger cars, light-duty trucks and medium-duty vehicles that the auto industry has already been complying with since 2009;
• Smog-forming pollutant and GHG emissions limits for light-duty vehicles that the auto industry has already been complying with since 2015 (Advanced Clean Cars I (ACC I) program);
• The 2022 reinstatement of the 2013 ACC I waiver after the EPA unlawfully purported to withdraw it in 2019;
• The Small Off-Road Engine amendments, which set exhaust standards for garden equipment and other polluting small engines in California.