Download the Code of Federal Regulations in XML.
The Electronic Code of Federal Regulations (e-CFR) is a regularly updated, unofficial editorial compilation of CFR material and Federal Register amendments produced by the National Archives and Records Administration's Office of the Federal Register (OFR) and the Government Printing Office.
Parallel Table of Authorities and Rules for the Code of Federal Regulations and the United States Code
Text | PDF
Find, review, and submit comments on Federal rules that are open for comment and published in the Federal Register using Regulations.gov.
Purchase individual CFR titles from the U.S. Government Online Bookstore.
Find issues of the CFR (including issues prior to 1996) at a local Federal depository library.
Electronic Code of Federal Regulations
Title 40: Protection of Environment
§51.902 Which classification and nonattainment area planning provisions of the CAA shall apply to areas designated nonattainment for the 1997 8-hour NAAQS?
(a) An area designated nonattainment for the 1997 8-hour NAAQS will be classified in accordance with section 181 of the CAA, as interpreted in §51.903(a), for purposes of the 1997 8-hour NAAQS, and will be subject to the requirements of subpart 2 that apply for that classification.
[77 FR 28841, May 14, 2012]