Attorney General Bonta Files Motion for Preliminary Injunction to Block Trump Administration’s Unlawful Reclassification of Clean Air Act Waivers

OAKLAND— California Attorney General Rob Bonta, Governor Gavin Newsom, and California Air Resources Board (CARB) today filed a motion for a preliminary injunction to block the Trump Administration’s recent actions targeting four Clean Air Act preemption waivers previously granted to California.  The U.S. Environmental Protection Agency (EPA) illegally reclassified these waivers as though they are “rules” subject to Congressional disapproval and sent them to Congress in an apparent pursuit of such disapproval. The four waivers — which concern CARB’s 2008 Greenhouse Gas Emission Standards for cars; CARB’s 2012 Emissions Standards for Cars (Advanced Clean Cars I Rule); and 2022 Small Offroad Engine Rule amendments — enable California to enforce state-level emission standards to address its severe air pollution. On Monday, California filed a lawsuit challenging EPA’s latest attack on state's efforts to improve air quality and protect public health.

“The Trump Administration is resorting to a familiar illegal playbook. Its continuous, outright assault on California’s waivers is blatantly politically motivated, and California won’t stand for this,” said Attorney General Bonta. “We’re asking the court to stop the Administration’s latest attack on our waivers that threatens both public health and good, green jobs that bolster our economy.”

The Clean Air Act requires the EPA to set federal emission standards for air pollutants from new motor vehicles or new motor vehicle engines (and for new off-road vehicles and engines) that cause or contribute to air pollution that endangers public health or welfare. The Clean Air Act allows California to enforce its own emission requirements independent of, and often more stringent than, EPA’s regulations, and the Act requires EPA to approve preemption waivers for those requirements absent certain, limited circumstances not present here. Historically, EPA — under both Republican and Democratic administrations — has granted California more than 75 preemption waivers for updates to the state’s emissions control programs. As Congress intended, these waivers have allowed California to improve those programs, which pre-existed the federal government’s efforts to regulate these emissions via the Clean Air Act.

The EPA has always taken the position that Clean Air Act preemption waivers are “orders,” not “rules,” as defined under relevant federal laws including the Congressional Review Act (CRA), which provides a streamlined process for Congress to disapprove federal agency rules. In February 2025, President Trump and EPA Administrator Lee Zeldin reversed course, purporting to reclassify three preemption waivers as “rules” and submitting them to Congress. In June 2025, Attorney General Bonta, joined by Governor Newsom and CARB, led a multistate lawsuit against the federal government challenging the unprecedented and unlawful attempt to attack California’s waivers using the CRA.

In their motion for preliminary injunction in this new case, California argues that:

• The state is likely to prevail on its claims that the Trump Administration’s reclassification violates the Administrative Procedure Act.
• The state is suffering irreparable harm from the Trump Administration’s recent actions.
• Granting the preliminary injunction would simply restore the status quo that existed for years before these unlawful actions and would not harm the Trump Administration.