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  2. Clean Air Act Overview

Clean Air Act Text

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  • What is the Clean Air Act?
  • Clean Air Act Table of Contents by Title

What is the Clean Air Act?

The Clean Air Act is the law that defines EPA's responsibilities for protecting and improving the nation's air quality and the stratospheric ozone layer. The last major change in the law, the Clean Air Act Amendments of 1990, was enacted by Congress in 1990. Legislation passed since then has made several minor changes.

The Clean Air Act, like other laws enacted by Congress, was incorporated into the United States Code as Title 42, Chapter 85. The House of Representatives maintains a current version of the U.S. Code, which includes Clean Air Act changes enacted since 1990.

This site provides links to sections of the U.S. Code containing the amended text of the Clean Air Act. Section numbers in the U.S. Code are different than the Clean Air Act's section numbers. The following table of contents gives corresponding section numbers in the Clean Air Act (CAA) and the U.S. Code (USC). Another difference is that titles in the Clean Air Act correspond to subchapters in the U.S. Code. 

composite of air pollution from various sources

Clean Air Act Table of Contents by Title

  • Title I - Air Pollution Prevention and Control
    • Part A - Air Quality and Emission Limitations (CAA § 101-131; USC § 7401-7431 )
    • Part B - Ozone Protection (replaced by Title VI)
    • Part C - Prevention of Significant Deterioration of Air Quality (CAA § 160-169b; USC § 7470-7492)
    • Part D - Plan Requirements for Nonattainment Areas (CAA § 171-193; USC § 7501-7515)
  • Title II - Emission Standards for Moving Sources
    • Part A - Motor Vehicle Emission and Fuel Standards (CAA § 201-219; USC § 7521-7554)
    • Part B - Aircraft Emission Standards (CAA § 231-234; USC § 7571-7574)
    • Part C - Clean Fuel Vehicles (CAA § 241-250; USC § 7581-7590)
  • Title III - General (CAA § 301-328; USC § 7601-7627)
  • Title IV - Noise Pollution (USC § 7641-7642). See Note at end of section.
  • Title IV-A - Acid Deposition Control (CAA § 401-416; USC § 7651-7651o) See Note at end of section.
  • Title V - Permits (CAA § 501-507; USC § 7661-7661f )
  • Title VI - Stratospheric Ozone Protection (CAA § 601-618; USC § 7671-7671q )

Note: The 1990 Clean Air Act Amendments added a new title IV, relating to acid deposition control, without repealing the existing title IV, relating to noise pollution. The U.S. Code designates the original title IV, noise pollution, as subchapter IV and the new title IV, acid deposition control, as subchapter IV-A.

Clean Air Act Overview

  • Progress Cleaning the Air
  • Air Pollution Challenges
  • Requirements and History
  • Role of Science and Technology
  • Roles of State, Local, Tribal and Federal Governments
  • Developing Programs Through Dialogue
  • Flexibility with Accountability
  • The Clean Air Act and the Economy
Contact Us About the Clean Air Act
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 28, 2025
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