# 40 CFR § 81.1: Definitions

> Federal · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/ecfr-40-81.1

## Section

- **Citation:** 40 CFR § 81.1
- **Heading:** Definitions
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** September 22, 2026
- **Source:** Publisher's official text
- **Location:** Title 40—Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS > PART 81—DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES > Subpart A—Meaning of Terms

## Text

As used in this part, all terms not defined herein shall have the meaning given them by the Act.
(a) Act means the Clean Air Act as amended (42 U.S.C. 7401, et seq.).
(b) Administrator means the Administrator of the Environmental Protection Agency or his authorized representative.
(c) Federal Indian Reservation, Indian Reservation or Reservation means all land within the limits of any Indian reservation under the jurisdiction of the United States government, notwithstanding the issuance of any patent, and including rights-of-way running through the reservation.
(d) Indian tribe or tribe means any Indian tribe, band, nation, or other organized group or community, including any Alaska Native village, which is federally recognized as eligible for the special programs and services provided by the United States to Indians because of their status as Indians.
(e) State means a state, the District of Columbia, the Commonwealth of Puerto Rico, the Virgin Islands, Guam, and American Samoa and includes the Commonwealth of the Northern Mariana Islands.
[36 FR 22421, Nov. 25, 1971, as amended at 63 FR 7274, Feb. 12, 1998]

## Nearby sections

- [40 CFR § 81.1 § 81.1 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.1.md)
- [40 CFR § 81.11 § 81.11 Scope.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.11.md)
- [40 CFR § 81.12 § 81.12 National Capital Interstate Air Quality Control Region (District of Columbia, Maryland, and Virginia).](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.12.md)
- [40 CFR § 81.13 § 81.13 New Jersey-New York-Connecticut Interstate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.13.md)
- [40 CFR § 81.14 § 81.14 Metropolitan Chicago Interstate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.14.md)
- [40 CFR § 81.15 § 81.15 Metropolitan Philadelphia Interstate Air Quality Control Region (Pennsylvania-New Jersey-Delaware).](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.15.md)
- [40 CFR § 81.16 § 81.16 Metropolitan Denver Intrastate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.16.md)
- [40 CFR § 81.17 § 81.17 Metropolitan Los Angeles Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.17.md)
- [40 CFR § 81.18 § 81.18 Metropolitan St. Louis Interstate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.18.md)
- [40 CFR § 81.19 § 81.19 Metropolitan Boston Intrastate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.19.md)
- [40 CFR § 81.20 § 81.20 Metropolitan Cincinnati Interstate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.20.md)
- [40 CFR § 81.21 § 81.21 San Francisco Bay Area Intrastate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.21.md)
- [40 CFR § 81.22 § 81.22 Greater Metropolitan Cleveland Intrastate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.22.md)
- [40 CFR § 81.23 § 81.23 Southwest Pennsylvania Intrastate Air Quality Control Region.](https://www.frixlaw.com/law-library/statutes/ecfr-40-81.23.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/ecfr-40-81.1. Check the current official text before relying on it. Not legal advice.