OAKLAND — California Attorney General Rob Bonta, California Governor Gavin Newsom, and the California Air Resources Board (CARB) today filed a lawsuit against the U.S. Environmental Protection Agency (EPA) challenging its latest attack on California's efforts to improve air quality and protect public health. Last week, EPA purported to reclassify four Clean Air Act preemption waivers previously granted to California as “rules” subject to Congressional disapproval and sent them to Congress in apparent pursuit of such disapproval. The four waivers — which allow California to implement CARB’s 2008 Greenhouse Gas Emission Standards for cars; CARB’s 2012 emissions standards for cars (Advanced Clean Cars I or ACC I Rule); the Biden Administration’s 2022 reinstatement of parts of the ACC I waiver after the first Trump Administration purported to administratively rescind them; and the 2022 Small Offroad Engine (SORE) Rule amendments — enable California to enforce state-level emission standards to address its severe air pollution. In over 50 years since the Clean Air Act was enacted, waivers have never been considered rules subject to Congressional disapproval. Nor have any other agency orders that adjudicate requests for permission, such as oil and gas leases or mining permits. However, last week, EPA purported to reclassify these waivers as rules and submitted them to Congress in an unlawful attempt to end-run administrative procedure and tee up a Congressional attack on California’s vehicle emissions rules. In a lawsuit filed in the U.S. District Court for the District of Columbia, Attorney General Bonta, Governor Newsom, and CARB challenge EPA’s unlawful reclassification of California’s waivers and ask the court to find EPA’s actions unlawful. 

“The Trump Administration is doubling down on its unlawful attack on California’s longstanding authority to address air pollution and adopt clean vehicle and equipment standards that protect our State and residents,” said Attorney General Bonta. “For fifty years, both Democratic and Republican administrations have agreed that EPA Clean Air Act waivers are not rules, and EPA's unlawful attempt to reclassify them — years after the fact — is an illegal attempt to take down these important tools. These latest illegal actions would mean more pollution, poorer air quality, more market uncertainty, and greater health risks for communities already overburdened by emissions. California will continue to fight against the Trump Administration's lawless overreach and vigorously defend our authority to protect the health and well-being of our communities and the environment.”   

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 adopt more stringent emission requirements independent of 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.

EPA has always taken the position that Clean Air Act preemption waivers are “orders,” not “rules,” and are thus not subject to the CRA.  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. Attorney General Bonta, joined by Governor Newsom and CARB, led a multistate lawsuit against the federal government challenging the unprecedented and unlawful attempt to use the CRA. 

The complaint filed today alleges that EPA’s attempt to reclassify California’s waivers violated the Administrative Procedure Act and was ultra vires.  The complaint asks the court to declare the EPA’s reclassification to be unlawful and to restore the status quo that existed before EPA acted.