California and the Clean Air Act (CAA) Waiver: Frequently Asked Questions
In the Air Quality Act of 1967 (P.L. 90-148), later amended to the Clean Air Act (CAA; codified at 42 U.S.C. §§7401 et seq.), Congress preempted state governments from adopting their own air pollutant emissions standards for new motor vehicles and new motor vehicle engines. Notwithstanding, Congress decided to provide an exemption for the State of California. Under CAA Section 209, California can apply to the U.S. Environmental Protection Agency (EPA) for a waiver from the federal preemption, and EPA is to grant this waiver absent certain disqualifying conditions. As of 2024, California has used this authority to receive more than 100 federal preemption waivers for new and amended state-level vehicle emissions standards. Further, in the CAA Amendments of 1990 (P.L. 101-549), Congress allowed other states to adopt California’s vehicle emissions standards under certain conditions. As of 2024, 17 states and the District of Columbia have used the authority under CAA Section 177 to adopt some subset of California’s standards. California estimates that itself and these “Section 177 States” accounted for more than 40% of new light-duty vehicle registrations and 25% of new heavy-duty vehicle registrations in the United States in 2023. This report examines some of the frequently asked questions regarding California’s federal preemption waiver authority for new vehicle emissions standards, including its origin, purpose, history, and regulatory process. This report also reviews associated actions by California, other states, the executive branch, Congress, and the federal courts.
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Supplemental Notes:
- This report is updated periodically while the text remains available at the URL indicated above. The actual date of publication, pagination, and other features may differ from that indicated in this record.
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Corporate Authors:
Congressional Research Service
Washington, DC United States -
Authors:
- Barczewski, Benjamin M
- Lattanzio, Richard K
- Peterson, Emily N
- Publication Date: 2024-8-30
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; References;
- Pagination: 33p
Subject/Index Terms
- TRT Terms: Exemption; Motor vehicles; Policy, legislation and regulation; Pollutants; Standards
- Identifier Terms: Clean Air Act
- Geographic Terms: California
- Subject Areas: Environment; Highways; Policy; Vehicles and Equipment;
Filing Info
- Accession Number: 01931603
- Record Type: Publication
- Report/Paper Numbers: R48168
- Files: TRIS
- Created Date: Sep 23 2024 9:05AM