September 2, 2025
The U.S. Environmental Protection Agency (EPA) recently announced it is proposing to disapprove California’s heavy-duty vehicle inspection and maintenance requirements as they apply to vehicles not registered in the state, including out-of-state and foreign-registered trucks, according to a story from Advanced Clean Tech News on Aug. 26. The EPA said the measure raises constitutional and federal law concerns, specifically pointing to the Commerce Clause and Section 110 of the Clean Air Act.
“California was not, and has never been, duly elected by the American people to run our great country,” said EPA Administrator Lee Zeldin. “EPA will not allow California to violate federal law, and we will not sit idly by while, in the name of climate change, they raise the cost of living on all Americans who rely on truck drivers and the products they deliver across the country.”
The proposal will be published in the Federal Register and open to public comment for 30 days before any final decision is made.
This move follows earlier EPA actions in February and June 2025 to roll back waivers granted under the Biden Administration for several of California’s clean-vehicle standards, including its Advanced Clean Cars II, Advanced Clean Trucks, and Heavy-Duty Engine Omnibus NOₓ rules. Those rollbacks relied on the Congressional Review Act and were followed by lawsuits filed by the Department of Justice against the California Air Resources Board over enforcement of preempted emissions standards through the Clean Truck Partnership.
California has long argued that its unique air quality challenges justify tougher emissions rules, and the state’s authority to adopt more stringent standards has historically been recognized through EPA waivers under the Clean Air Act. Federal officials now contend that applying California’s rules to out-of-state and foreign-registered vehicles exceeds constitutional limits and undermines national consistency in regulation.
The next step will be the 30-day comment period, during which stakeholders including states, trucking fleets, manufacturers, and environmental groups may weigh in. Any final action from EPA is expected to draw legal challenges, particularly if California or its allies dispute both the agency’s authority and its interpretation of federal law.