Site Feedback

Title 40

Displaying title 40, up to date as of 7/14/2026. Title 40 was last amended 7/14/2026.
eCFR Content

The Code of Federal Regulations (CFR) is the official legal print publication containing the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. It is not an official legal edition of the CFR.

Learn more about the eCFR, its status, and the editorial process.

Title 40Protection of EnvironmentPart / Section
Chapter IEnvironmental Protection Agency1 – 1099
Subchapter CAir Programs50 – 99
Part 52Approval and Promulgation of Implementation Plans52.01 – 52.2999
Subpart AGeneral Provisions52.01 – 52.46
§ 52.01Definitions.
§ 52.02Introduction.
§ 52.04Classification of regions.
§ 52.05Public availability of emission data.
§ 52.06Legal authority.
§ 52.07Control strategies.
§ 52.08Rules and regulations.
§ 52.09Compliance schedules.
§ 52.10Review of new sources and modifications.
§ 52.11Prevention of air pollution emergency episodes.
§ 52.12Source surveillance.
§ 52.13Air quality surveillance; resources; intergovernmental cooperation.
§ 52.14State ambient air quality standards.
§ 52.15Public availability of plans.
§ 52.16Submission to Administrator.
§ 52.17Severability of provisions.
§ 52.18Abbreviations.
§ 52.20Attainment dates for national standards.
§ 52.21Prevention of significant deterioration of air quality.
§ 52.23Violation and enforcement.
§ 52.24Statutory restriction on new sources.
§ 52.26 [Reserved]
§ 52.27Protection of visibility from sources in attainment areas.
§ 52.28Protection of visibility from sources in nonattainment areas.
§ 52.29 [Reserved]
§ 52.30Criteria for limiting application of sanctions under section 110(m) of the Clean Air Act on a statewide basis.
§ 52.31Selection of sequence of mandatory sanctions for findings made pursuant to section 179 of the Clean Air Act.
§ 52.32Sanctions following findings of SIP inadequacy.
§ 52.33Compliance certifications.
§ 52.34Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.
§ 52.35What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of nitrogen oxides?
§ 52.36What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate Rule (CAIR) relating to emissions of sulfur dioxide?
§ 52.37 [Reserved]
§ 52.38What are the requirements of the Federal Implementation Plans (FIPs) for the Cross-State Air Pollution Rule (CSAPR) relating to emissions of nitrogen oxides?
§ 52.39What are the requirements of the Federal Implementation Plans (FIPs) for the Cross-State Air Pollution Rule (CSAPR) relating to emissions of sulfur dioxide?
§ 52.40What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from sources not subject to the CSAPR ozone season trading program?
§ 52.41What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from the Pipeline Transportation of Natural Gas Industry?
§ 52.42What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from the Cement and Concrete Product Manufacturing Industry?
§ 52.43What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from the Iron and Steel Mills and Ferroalloy Manufacturing Industry?
§ 52.44What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from the Glass and Glass Product Manufacturing Industry?
§ 52.45What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from the Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, the Pulp, Paper, and Paperboard Mills Industries, Metal Ore Mining, and the Iron and Steel and Ferroalloy Manufacturing Industries?
§ 52.46What are the requirements of the Federal Implementation Plans (FIPs) relating to ozone season emissions of nitrogen oxides from Municipal Waste Combustors?