Public Law 119-73 (01/23/2026)

42 U.S.C. § 7409

National primary and secondary ambient air quality standards

(a)

Promulgation

(1)
The Administrator—
(A)
within 30 days after , shall publish proposed regulations prescribing a national primary ambient air quality standard and a national secondary ambient air quality standard for each air pollutant for which air quality criteria have been issued prior to such date; and
(B)
after a reasonable time for interested persons to submit written comments thereon (but no later than 90 days after the initial publication of such proposed standards) shall by regulation promulgate such proposed national primary and secondary ambient air quality standards with such modifications as he deems appropriate.
(2)
With respect to any air pollutant for which air quality criteria are issued after , the Administrator shall publish, simultaneously with the issuance of such criteria and information, proposed national primary and secondary ambient air quality standards for any such pollutant. The procedure provided for in paragraph (1)(B) of this subsection shall apply to the promulgation of such standards.
(b)

Protection of public health and welfare

(1)
National primary ambient air quality standards, prescribed under subsection (a) shall be ambient air quality standards the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health. Such primary standards may be revised in the same manner as promulgated.
(2)
Any national secondary ambient air quality standard prescribed under subsection (a) shall specify a level of air quality the attainment and maintenance of which in the judgment of the Administrator, based on such criteria, is requisite to protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air. Such secondary standards may be revised in the same manner as promulgated.
(c)

National primary ambient air quality standard for nitrogen dioxide

2section 7408(c) of this titleThe Administrator shall, not later than one year after , promulgate a national primary ambient air quality standard for NO concentrations over a period of not more than 3 hours unless, based on the criteria issued under , he finds that there is no significant evidence that such a standard for such a period is requisite to protect public health.

(d)

Review and revision of criteria and standards; independent scientific review committee; appointment; advisory functions

(1)
section 7408 of this titlesection 7408 of this title Not later than , and at five-year intervals thereafter, the Administrator shall complete a thorough review of the criteria published under and the national ambient air quality standards promulgated under this section and shall make such revisions in such criteria and standards and promulgate such new standards as may be appropriate in accordance with and subsection (b) of this section. The Administrator may review and revise criteria or promulgate new standards earlier or more frequently than required under this paragraph.
(2)
(A)
The Administrator shall appoint an independent scientific review committee composed of seven members including at least one member of the National Academy of Sciences, one physician, and one person representing State air pollution control agencies.
(B)
section 7408 of this titlesection 7408 of this title Not later than , and at five-year intervals thereafter, the committee referred to in subparagraph (A) shall complete a review of the criteria published under and the national primary and secondary ambient air quality standards promulgated under this section and shall recommend to the Administrator any new national ambient air quality standards and revisions of existing criteria and standards as may be appropriate under and subsection (b) of this section.
(C)
Such committee shall also (i) advise the Administrator of areas in which additional knowledge is required to appraise the adequacy and basis of existing, new, or revised national ambient air quality standards, (ii) describe the research efforts necessary to provide the required information, (iii) advise the Administrator on the relative contribution to air pollution concentrations of natural as well as anthropogenic activity, and (iv) advise the Administrator of any adverse public health, welfare, social, economic, or energy effects which may result from various strategies for attainment and maintenance of such national ambient air quality standards.

July 14, 1955, ch. 360Pub. L. 91–604, § 4(a)84 Stat. 1679Pub. L. 95–95, title I, § 10691 Stat. 691(, title I, § 109, as added , , ; amended , , .)

Editorial Notes

Codification

section 1857c–4 of this titleSection was formerly classified to .

Prior Provisions

Pub. L. 91–604section 7416 of this titleA prior section 109 of act , was renumbered section 116 by and is classified to .

Amendments

Pub. L. 95–95, § 106(b)1977—Subsec. (c). , added subsec. (c).

Pub. L. 95–95, § 106(a)Subsec. (d). , added subsec. (d).

Statutory Notes and Related Subsidiaries

Effective Date of 1977 Amendment

Pub. L. 95–95section 406(d) of Pub. L. 95–95section 7401 of this titleAmendment by effective , except as otherwise expressly provided, see , set out as a note under .

Modification or Rescission of Rules, Regulations, Orders, Determinations, Contracts, Certifications, Authorizations, Delegations, and Other Actions

Pub. L. 95–95Pub. L. 95–95section 406(b) of Pub. L. 95–95section 7401 of this titleAll rules, regulations, orders, determinations, contracts, certifications, authorizations, delegations, or other actions duly issued, made, or taken by or pursuant to act , the Clean Air Act, as in effect immediately prior to the date of enactment of [] to continue in full force and effect until modified or rescinded in accordance with act , as amended by [this chapter], see , set out as an Effective Date of 1977 Amendment note under .

Termination of Advisory Committees

section 1013 of Title 5Advisory committees established after , to terminate not later than the expiration of the 2-year period beginning on the date of their establishment, unless, in the case of a committee established by the President or an officer of the Federal Government, such committee is renewed by appropriate action prior to the expiration of such 2-year period, or in the case of a committee established by the Congress, its duration is otherwise provided for by law. See , Government Organization and Employees.

Role of Secondary Standards

Pub. L. 101–549, title VIII, § 817104 Stat. 2697

“(a)

Report .—

The Administrator shall request the National Academy of Sciences to prepare a report to the Congress on the role of national secondary ambient air quality standards in protecting welfare and the environment. The report shall:
“(1)
42 U.S.C. 7408 include information on the effects on welfare and the environment which are caused by ambient concentrations of pollutants listed pursuant to section 108 [] and other pollutants which may be listed;
“(2)
estimate welfare and environmental costs incurred as a result of such effects;
“(3)
examine the role of secondary standards and the State implementation planning process in preventing such effects;
“(4)
determine ambient concentrations of each such pollutant which would be adequate to protect welfare and the environment from such effects;
“(5)
estimate the costs and other impacts of meeting secondary standards; and
“(6)
42 U.S.C. 7401 consider other means consistent with the goals and objectives of the Clean Air Act [ et seq.] which may be more effective than secondary standards in preventing or mitigating such effects.
“(b)

Submission to Congress; Comments; Authorization .—

(1)
The report shall be transmitted to the Congress not later than 3 years after the date of enactment of the Clean Air Act Amendments of 1990 [].
“(2)
At least 90 days before issuing a report the Administrator shall provide an opportunity for public comment on the proposed report. The Administrator shall include in the final report a summary of the comments received on the proposed report.
“(3)
There are authorized to be appropriated such sums as are necessary to carry out this section.”
, , , provided that: