Providing congressional disapproval under chapter 8 of title 5, United States Code, of the rule submitted by the Environmental Protection Agency relating to "California State Motor Vehicle and Engine Pollution Control Standards; Heavy-Duty Vehicle and Engine Emission Warranty and Maintenance Provisions; Advanced Clean Trucks; Zero Emission Airport Shuttle; Zero-Emission Power Train Certification; Waiver of Preemption; Notice of Decision".

This law overturns a 2023 Environmental Protection Agency decision that approved California's request for a waiver to enforce stricter vehicle emission standards. Specifically, the law invalidates EPA approval of California's Advanced Clean Trucks program, which required increasing percentages of zero-emission truck sales; Zero Emission Airport Shuttle standards; and Zero-Emission Power Train Certification rules. These programs had been designed to reduce emissions from heavy-duty vehicles operating in California and other states that adopted California's standards.

By nullifying the EPA's waiver approval, this law prevents California from enforcing these emission standards within its borders and blocks other states from adopting California's standards as well. The law effectively preempts California's authority to set these vehicle emission requirements, asserting that such regulations fall outside California's authority under the Clean Air Act. The law also prevents the EPA from issuing future regulations that are substantially similar to the disapproved standards without new congressional authorization.

The practical impact affects vehicle manufacturers, trucking companies, and fleet operators who had begun planning for compliance with California's stricter emission standards. Companies that had committed to meeting these standards may need to reassess their compliance obligations and product development plans. However, some major manufacturers had entered into voluntary agreements with California to comply with these regulations regardless of legal challenges, which may continue to influence their operations.

The law took effect upon the President's signature on June 12, 2025. It represents a significant shift in federal authority over state environmental regulations, with supporters arguing it prevents one state from imposing nationwide vehicle standards and critics contending it limits state environmental protection efforts.