Order Code RL30853
CRS Report for Congress
Received through the CRS Web
Clean Air Act: A Summary of the Act
and Its Major Requirements
Updated May 9, 2005
James E. McCarthy, Coordinator
Specialist in Environmental Policy
Resources, Science, and Industry Division
Congressional Research Service ˜ The Library of Congress

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Clean Air Act: A Summary of the Act
and Its Major Requirements
Summary
This report summarizes the Clean Air Act and its major regulatory requirements.
It excerpts, with minor modifications, the Clean Air Act chapter of CRS Report
RL30798, which summarizes a dozen environmental statutes that form the basis for
the programs of the Environmental Protection Agency.
The principal statute addressing air quality concerns, the Clean Air Act was first
enacted in 1955, with major revisions in 1970, 1977, and 1990. The Act requires
EPA to set health-based standards for ambient air quality, sets deadlines for the
achievement of those standards by state and local governments, and requires EPA to
set national emission standards for large or ubiquitous sources of air pollution,
including motor vehicles, power plants, and other industrial sources. In addition, the
Act mandates emission controls for sources of 188 hazardous air pollutants, requires
the prevention of significant deterioration of air quality in areas with clean air,
requires a program to restore visibility impaired by regional haze in national parks
and wilderness areas, and implements the Montreal Protocol to phase out most
ozone-depleting chemicals.
This report describes the Act’s major provisions and provides tables listing all
major amendments, with the year of enactment and Public Law number, and cross-
referencing sections of the Act with the major U.S. Code sections of the codified
statute.

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Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
National Ambient Air Quality Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
State Implementation Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Nonattainment Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Requirements for Ozone Nonattainment Areas . . . . . . . . . . . . . . . . . . . 5
Requirements for Carbon Monoxide Nonattainment Areas . . . . . . . . . 7
Requirements for Particulate Nonattainment Areas . . . . . . . . . . . . . . . . 8
Emission Standards for Mobile Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Hazardous Air Pollutants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
New Source Performance Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Solid Waste Incinerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Prevention of Significant Deterioration / Regional Haze . . . . . . . . . . . . . . 12
Acid Deposition Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Permits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Enforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Stratospheric Ozone Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Selected References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
List of Tables
Table 1. Clean Air Act and Amendments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Table 2. Ozone Nonattainment Classifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 3. Major U.S. Code Sections of the Clean Air Act . . . . . . . . . . . . . . . . . . 18

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Clean Air Act: A Summary of the Act
and Its Major Requirements
Introduction
The authorities and responsibilities of the Environmental Protection Agency
(EPA) derive primarily from a dozen major environmental statutes. This report
provides a concise summary of one of those statutes, the Clean Air Act. It provides
a very brief history of federal involvement in air quality regulation and of the
provisions added by legislation in 1970, 1977, and 1990; it explains major authorities
contained in the Act; it defines key terms; and it lists references for more detailed
information on the Act and its implementation.
While this report attempts to present the essence of the Act, it is necessarily
incomplete. Many details and secondary provisions are omitted. In addition, the
report describes the statute largely without discussing its implementation. Statutory
deadlines to control emissions and achieve particular mandates have often been
missed as a result of delayed standard-setting by EPA, delayed action on
implementation by states and local governments, or law suits brought by interested
parties. Other CRS products, including CRS Issue Brief IB10137 (Clean Air Act
Issues in the 109th Congress) and about a dozen CRS reports discuss implementation
concerns and current issues. Readers interested in a more comprehensive discussion
of the history of the Act are referred to CRS Report 83-34 ENR, Environmental
Protection: An Historical Review of the Legislation and Programs of the Environ-
mental Protection Agency.
Overview
The Clean Air Act, codified as 42 U.S.C. 7401 et seq., seeks to protect human
health and the environment from emissions that pollute ambient, or outdoor, air. It
requires the Environmental Protection Agency to establish minimum national
standards for air quality, and assigns primary responsibility to the states to assure
compliance with the standards. Areas not meeting the standards, referred to as
“nonattainment areas,” are required to implement specified air pollution control
measures. The Act establishes federal standards for mobile sources of air pollution,
for sources of 188 hazardous air pollutants, and for the emissions that cause acid rain.
It establishes a comprehensive permit system for all major sources of air pollution.
It also addresses the prevention of pollution in areas with clean air and protection of
the stratospheric ozone layer.

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Table 1. Clean Air Act and Amendments
(codified generally as 42 U.S.C. 7401-7671)
Year
Act
Public Law Number
1955
Air Pollution Control Act
P.L. 84-159
1959
Reauthorization
P.L. 86-353
1960
Motor vehicle exhaust study
P.L. 86-493
1963
Clean Air Act Amendments
P.L. 88-206
1965
Motor Vehicle Air Pollution Control Act
P.L. 89-272, Title I
1966
Clean Air Act Amendments of 1966
P.L. 89-675
1967
Air Quality Act of 1967
National Air Emission Standards Act
P.L. 90-148
1970
Clean Air Act Amendments of 1970
P.L. 91-604
1973
Reauthorization
P.L. 93-13
1974
Energy Supply and Environmental Coordination Act
of 1974
P.L. 93-319
1977
Clean Air Act Amendments of 1977
P.L. 95-95
1980
Acid Precipitation Act of 1980
P.L. 96-294, Title VII
1981
Steel Industry Compliance Extension Act of 1981
P.L. 97-23
1987
Clean Air Act 8-month Extension
P.L. 100-202
1990
Clean Air Act Amendments of 1990
P.L. 101-549
1995-96
Relatively minor laws amending the Act
P.L. 104-6, 59, 70, 260
1999
Chemical Safety Information, Site Security and Fuels
Regulatory Relief Act
P.L. 106-40
2004
Amendments to §209 re small engines
P.L. 108-199, Division
G, Title IV, Section 428
Like many other programs administered by the Environmental Protection
Agency, federal efforts to control air pollution have gone through several phases,
beginning with information collection, research, and technical assistance, before
being strengthened in subsequent amendments, notably the Clean Air Act
Amendments of 1970, 1977, and 1990.
The 1970 amendments established the procedures under which EPA sets
national standards for air quality, required a 90% reduction in emissions from new
automobiles by 1975, established a program to require the best available control
technology at major new sources of air pollution, established a program to regulate
air toxics, and greatly strengthened federal enforcement authority. The 1977
amendments adjusted the auto emission standards, extended deadlines for the
attainment of air quality standards, and added the Prevention of Significant
Deterioration program to protect air cleaner than national standards.
Changes to the Act in 1990 included provisions to (1) classify nonattainment
areas according to the extent to which they exceed the standard, tailoring deadlines,
planning, and controls to each area’s status; (2) tighten auto and other mobile source
emission standards; (3) require reformulated and alternative fuels in the most
polluted areas; (4) revise the air toxics section, establishing a new program of
technology-based standards and addressing the problem of sudden, catastrophic
releases of toxics; (5) establish an acid rain control program, with a marketable
allowance scheme to provide flexibility in implementation; (6) require a state-run
permit program for the operation of major sources of air pollutants; (7) implement
the Montreal Protocol to phase out most ozone-depleting chemicals; and (8) update

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CRS-3
the enforcement provisions so that they parallel those in other pollution control acts,
including authority for EPA to assess administrative penalties.
The 1990 amendments also authorized appropriations for clean air programs
through FY1998. The Act has not been reauthorized since then. House rules require
enactment of an authorization before an appropriation bill can be considered; but this
requirement can be waived and frequently has been. Thus, while authorization of
appropriations in the Clean Air Act (and most other environmental statutes) have
expired, programs have continued and have been funded. The Act’s other legal
authorities, to issue and enforce regulations, are, for the most part, permanent and are
not affected by the lack of authorization.
The remainder of this report describes major programs required by the Act, with
an emphasis on the changes established by the 1990 amendments.
National Ambient Air Quality Standards
In section 109, the Act requires EPA to establish National Ambient Air Quality
Standards (NAAQS) for several types of air pollutants. The NAAQS must be
designed to protect public health and welfare with an adequate margin of safety.
Using this authority, EPA has promulgated NAAQS for six air pollutants: sulfur
dioxide (SO ), particulate matter (PM and PM ), nitrogen dioxide (NO ), carbon
2
2.5
10
2
monoxide (CO), ozone,1 and lead. The Act requires EPA to review the scientific data
upon which the standards are based, and revise the standards, if necessary, every five
years. More often than not, however, EPA has taken more than five years in
reviewing and revising the standards.
Originally, the Act required that the NAAQS be attained by 1977 at the latest,
but the states experienced widespread difficulty in complying with these deadlines.
As a result, the deadlines have been extended several times. Under the 1990
amendments, areas not in attainment with NAAQS must meet special compliance
schedules, staggered according to the severity of an area’s air pollution problem. The
amendments also established specific requirements for each nonattainment category,
as described below.
State Implementation Plans
While the Act authorizes the EPA to set NAAQS, the states are responsible for
establishing procedures to attain and maintain the standards. Under Section 110 of
the Act, the states adopt plans, known as State Implementation Plans (SIPs), and
submit them to EPA to ensure that they are adequate to meet statutory requirements.
SIPs are based on emission inventories and computer models to determine
whether air quality violations will occur. If these data show that standards would be
1 Unlike the other NAAQS pollutants, ozone is not directly emitted, but rather is formed in
the atmosphere by the interaction of volatile organic compounds (VOCs) and nitrogen
oxides (NOx) in the presence of sunlight. The control of ozone is, thus, based on regulating
emissions of VOCs and NOx.

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exceeded, the state imposes additional controls on existing sources to ensure that
emissions do not cause “exceedances” of the standards. Proposed new and modified
sources must obtain state construction permits in which the applicant shows how the
anticipated emissions will not exceed allowable limits. In nonattainment areas,
emissions from new or modified sources must also be offset by reductions in
emissions from existing sources.
The 1990 amendments require EPA to impose sanctions in areas which fail to
submit a SIP, fail to submit an adequate SIP, or fail to implement a SIP: unless the
state corrects such failures, a 2-to-1 emissions offset for the construction of new
polluting sources is imposed 18 months after notification to the state, and a ban on
most federal highway grants is imposed six months later. An additional ban on air
quality grants is discretionary. Ultimately, a Federal Implementation Plan may be
imposed if the state fails to submit or implement an adequate SIP.
The amendments also require that, in nonattainment areas, no federal permits
or financial assistance may be granted for activities that do not “conform” to a State
Implementation Plan. This requirement can cause a temporary suspension in funding
for most highway and transit projects if an area fails to demonstrate that the
emissions caused by such projects are consistent with attainment and maintenance
of ambient air quality standards. Demonstrating conformity of transportation plans
and SIPs is required in nonattainment areas at least every two years.
Nonattainment Requirements
In a major departure from the prior law, the 1990 Clean Air Act Amendments
group nonattainment areas into classifications based on the extent to which the
NAAQS is exceeded, and establish specific pollution controls and attainment dates
for each classification. These requirements are described here as spelled out in
Sections 171-193 of the Act.2
Nonattainment areas are classified on the basis of a “design value,” which is
derived from the pollutant concentration (in parts per million or micrograms per
cubic meter) recorded by air quality monitoring devices. The design value for the 1-
hour ozone standard is the fourth highest hourly reading measured during the most
recent three-year period. Using these design values, the Act created five classes of
ozone nonattainment, as shown in Table 2. Only Los Angeles fell into the “extreme”
class, but 97 other areas were classified in one of the other four ozone categories. A
simpler classification system establishes moderate and serious nonattainment areas
for carbon monoxide and particulate matter with correspondingly more stringent
control requirements for the more polluted class.
2 EPA has modified the ozone standard, specified in the statute as 0.12 parts per million
averaged over a 1-hour period, to 0.08 parts per million averaged over an 8-hour period,
through regulations promulgated in July 1997. In April 2004, the agency promulgated an
implementation rule for the new 8-hour standard. Under this rule, the 1-hour standard would
be revoked as of June 15, 2005, and areas that had not yet attained it would be converted to
new classifications depending on their 8-hour concentration of ozone. The revocation of the
1-hour standard has been challenged in court, and it is unclear whether the agency’s
implementation plan will supplant the statutory provisions.

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Table 2. Ozone Nonattainment Classifications
Class
Marginal
Moderate
Serious
Severe
Extreme
Deadline
1993
1996
1999 2005-07*
2010
Areas**
42 areas
32 areas
14 areas
9 areas
1 area
Design
0.121 ppm-
0.138 ppm-
0.160 ppm-
0.180 ppm-
>0.280 ppm
Value
0.138 ppm
0.160 ppm
0.180 ppm
0.280 ppm
*Areas with a 1988 design value between 0.190 and 0.280 ppm have 17 years to attain; others have 15 years.
** Number of areas in each category as of the date of enactment.
As shown in the table, for ozone nonattainment areas the deadlines for
attainment stretch from 1993 to 2010, depending on the severity of the problem.
(Under the 8-hour rule, these deadlines will be changed to 2007 to 2021.) For carbon
monoxide, the attainment date for moderate areas was December 31, 1995, and for
serious areas, December 31, 2000. For particulate matter, the deadline for areas
designated moderate nonattainment as of 1990 was December 31, 1994; for those
areas subsequently designated as moderate, the deadline is six years after designation.
For serious areas, the respective deadlines are December 31, 2001 or 10 years after
designation.
Requirements for Ozone Nonattainment Areas. Although areas with
more severe air pollution problems have a longer time to meet the standards, more
stringent control requirements are imposed in areas with worse pollution. A
summary of the primary ozone control requirements for each nonattainment category
follows.
Marginal Areas
! Inventory emissions sources (to be updated every three years).
! Require 1.1 to 1 offsets (i.e., new major emission sources of volatile
organic compounds [VOCs] must reduce VOC emissions from
existing facilities in the area by 10% more than the emissions of the
new facility).
! Impose reasonably available control technology (RACT) on all
major sources emitting more than 100 tons per year for the nine
industrial categories where EPA had already issued control
technique guidelines describing RACT prior to 1990.
Moderate Areas
! Meet all requirements for marginal areas.
! Impose a 15% reduction in VOC emissions in six years.

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! Adopt a basic vehicle inspection and maintenance program.
! Impose RACT on all major sources emitting more than 100 tons per
year for all additional industrial categories where EPA will issue
control technique guidelines describing RACT.
! Require vapor recovery at gas stations selling more than 10,000
gallons per month.
! Require 1.15 to 1 offsets.
Serious Areas
! Meet all requirements for moderate areas.
! Reduce definition of a major source of VOCs from emissions of 100
tons per year to 50 tons per year for the purpose of imposing RACT.
! Reduce VOCs 3% annually for years 7 to 9 after the 15% reduction
already required by year 6.
! Improve monitoring.
! Adopt an enhanced vehicle inspection and maintenance program.
! Require fleet vehicles to use clean alternative fuels.
! Adopt transportation control measures if the number of vehicle miles
traveled in the area is greater than expected.
! Require 1.2 to 1 offsets.
! Adopt contingency measures if the area does not meet required VOC
reductions.
Severe Areas
! Meet all requirements for serious areas.
! Reduce definition of a major source of VOCs from emissions of 50
tons per year to 25 tons per year for the purpose of imposing RACT.
! Adopt specified transportation control measures.
! Implement a reformulated gasoline program.
! Require 1.3 to 1 offsets.
! Impose $5,000 per ton penalties on major sources if the area does
not meet required reductions.

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Extreme Areas
! Meet all requirements for severe areas.
! Reduce definition of a major source of VOCs from emissions of 25
tons per year to 10 tons per year for the purpose of imposing RACT.
! Require clean fuels or advanced control technology for boilers
emitting more than 25 tons per year of NO .
x
! Require 1.5 to 1 offsets.
As noted, EPA promulgated a new, 8-hour ozone standard in July 1997.
Following extensive court challenges, the agency designated nonattainment areas for
the new standard on April 15, 2004. State Implementation Plans must be submitted
within three years of an area’s designation.
Requirements for Carbon Monoxide Nonattainment Areas. As with
ozone nonattainment areas, carbon monoxide (CO) nonattainment areas are subjected
to specified control requirements, with more stringent requirements in Serious
nonattainment areas. A summary of the primary CO control requirements for each
nonattainment category follows.
Moderate Areas
! Conduct an inventory of emissions sources.
! Forecast total vehicle miles traveled in the area.
! Adopt an enhanced vehicle inspection and maintenance program.
! Demonstrate annual improvements sufficient to attain the standard.
Serious Areas
! Adopt specified transportation control measures.
! Implement an oxygenated fuels program for all vehicles in the area.
! Reduce definition of a major source of CO from emissions of 100
tons per year to 50 tons per year if stationary sources contribute
significantly to the CO problem.
Serious areas failing to attain the standard by the deadline have to revise their
SIP and demonstrate reductions of 5% per year until the standard is attained.

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Requirements for Particulate Nonattainment Areas. Particulate (PM )
10
nonattainment areas are also subject to specified control requirements. These are:
Moderate Areas
! Require permits for new and modified major stationary sources of
PM .
10
! Impose reasonably available control measures (RACM).
Serious Areas
! Impose best available control measures (BACM).
! Reduce definition of a major source of PM from 100 tons per year
10
to 70 tons per year.
In July 1997, EPA promulgated new standards for fine particulates (PM ). The
2.5
PM standards were also subject to court challenges. The absence of a monitoring
2.5
network capable of measuring the pollutant delayed implementation as well.
Nonattainment areas for PM were designated on January 5, 2005. States will have
2.5
three years subsequent to designation to submit State Implementation Plans.
Emission Standards for Mobile Sources
Title II of the Clean Air Act has required emission standards for automobiles
since 1968. The 1990 amendments significantly tightened these standards: for cars,
the hydrocarbon standard was reduced by 40% and the nitrogen oxides (NO )
x
standard by 50%. The new standards — referred to as “Tier 1” standards — were
phased in over the 1994-1996 model years.
The amendments envisioned a further set of reductions (“Tier 2” standards), but
not before model year 2004. For Tier 2 standards to be promulgated, the agency was
first required to report to Congress concerning the need for further emission
reductions, the availability of technology to achieve such reductions, and the cost-
effectiveness of such controls compared to other means of attaining air quality
standards. EPA submitted this report to Congress in August 1998, concluding that
further emission reductions were needed and that technology to achieve such
reductions was available and cost-effective. Tier 2 standards, requiring emission
reductions of 77% to 95% from cars and light trucks were promulgated in February
2000, and are being phased in over the 2004-2009 model years. To facilitate the use
of more effective emission controls, the standards also require a more than 90%
reduction in the sulfur content of gasoline, beginning in 2004.
The 1990 amendments also required that oxygenated gasoline, designed to
reduce emissions of carbon monoxide, be sold in the worst CO nonattainment areas
and that “reformulated” gasoline (RFG), designed to reduce emissions of volatile
organic compounds and toxic air pollutants, be sold in the nine worst ozone
nonattainment areas (Los Angeles, San Diego, Houston, Baltimore, Philadelphia,
New York, Hartford, Chicago, and Milwaukee); metropolitan Washington, D.C., and

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CRS-9
four areas in California were added to the mandatory list later. Other ozone
nonattainment areas can opt in to the RFG program; as of 2005, additional areas in
11 states had done so.
Use of alternative fuels and development of cleaner engines was to be
stimulated by the Clean-Fuel Fleet Program. In all of the most seriously polluted
ozone and CO nonattainment areas, centrally fueled fleets of 10 or more passenger
cars and light-duty trucks must purchase at least 30% clean-fuel vehicles when they
add new vehicles to existing fleets, starting in 1999. (The Act originally required the
program to begin in 1998, but the start was delayed by a year.) The percentage rose
to 50% in 2000 and 70% in 2001. Heavy-duty fleets are required to purchase at least
50% clean-fuel vehicles annually. A clean fuel vehicle is one which meets Low
Emission Vehicle (LEV) standards and operates on reformulated gasoline,
reformulated diesel, methanol, ethanol, natural gas, liquefied petroleum gas,
hydrogen, or electricity.
In addition to the above program, California’s Zero Emission Vehicle (ZEV)
program also is intended to promote the development of alternative fuels and
vehicles. Section 209(b) of the Clean Air Act grants California the authority to
develop its own vehicle emissions standards if those standards are at least as stringent
as the federal standards. In addition to setting more stringent standards for all
vehicles, California used this authority to establish a program requiring auto
manufacturers to sell ZEVs (electric or hydrogen fuel cell vehicles) in the state
beginning in 2003. This program has been substantially modified since it was
enacted, and now allows credit for hybrid and partial ZEV vehicles in addition to true
ZEVs, but it has served as an incubator for lower emission technologies since its
adoption. Section 177 of the Act allows other states to adopt California’s stricter
standards: Maine, Massachusetts, New York, and Vermont have done so, and three
other northeastern states (Connecticut, New Jersey, and Rhode Island) will do so over
the next few years.
The 1990 amendments also imposed tighter requirements on certification (an
auto’s useful life is defined as 100,000 miles instead of the earlier 50,000 miles), on
emissions allowed during refueling, on low temperature CO emissions, on in-use
performance over time, and on warranties for the most expensive emission control
components (8 years/80,000 miles for the catalytic converter, electronic emissions
control unit, and onboard emissions diagnostic unit). Regulations were also extended
to include nonroad fuels and engines.
Standards for trucks and buses using diesel engines were also strengthened. The
1990 amendments required new urban buses to reduce emissions of diesel
particulates 92% by 1996, and all other heavy-duty diesel engines to achieve an 83%
reduction by the same year. NO emissions must also be reduced, 33% by 1998.
x
Authority to further strengthen these standards led to promulgation in January 2001
of new emission standards requiring a further 90%-95% reduction in emissions
phased in over the 2007-2010 model years, and a reduction of 97% in the allowable
amount of sulfur in highway diesel fuel.

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Hazardous Air Pollutants3
Completely rewritten by the Clean Air Act Amendments of 1990, Section 112
of the Act establishes programs for protecting the public health and environment
from exposure to toxic air pollutants. As revised by the 1990 amendments, the
section contains four major provisions: Maximum Achievable Control Technology
(MACT) requirements; health-based standards; standards for stationary “area
sources” (small, but numerous sources, such as gas stations or dry cleaners, that
collectively emit significant quantities of hazardous pollutants); and requirements
for the prevention of catastrophic releases.
First, EPA is to establish technology-based emission standards, called MACT
standards, for sources of 188 pollutants listed in the legislation, and to specify
categories of sources subject to the emission standards.4 EPA is to revise the
standards periodically (at least every eight years). EPA can, on its initiative or in
response to a petition, add or delete substances or source categories from the lists.
Section 112 establishes a presumption in favor of regulation for the designated
chemicals; it requires regulation of a designated pollutant unless EPA or a petitioner
is able to show “that there is adequate data on the health and environmental effects
of the substance to determine that emissions, ambient concentrations,
bioaccumulation or deposition of the substance may not reasonably be anticipated to
cause any adverse effects to human health or adverse environmental effects.”
EPA is required to set standards for sources of the listed pollutants that achieve
“the maximum degree of reduction in emissions” taking into account cost and other
non-air-quality factors. These MACT standards for new sources “shall not be less
stringent than the most stringent emissions level that is achieved in practice by the
best controlled similar source.” The standards for existing sources may be less
stringent than those for new sources, but must be no less stringent than the emission
limitations achieved by either the best performing 12% of existing sources (if there
are more than 30 such sources in the category or subcategory) or the best performing
5 similar sources (if there are fewer than 30). Existing sources are given three years
following promulgation of standards to achieve compliance, with a possible one-year
extension; additional extensions may be available for special circumstances or for
certain categories of sources. Existing sources that achieve voluntary early emissions
reductions will receive a six-year extension for compliance with MACT.
The second major provision of Section 112 directs EPA to set health-based
standards to address situations in which a significant residual risk of adverse health
effects or a threat of adverse environmental effects remains after installation of
MACT. This provision requires that EPA, after consultation with the Surgeon
General of the United States, submit a report to Congress on the public health
3 This section of the report was written by Linda-Jo Schierow, Specialist in Environmental
Policy.
4 The 1990 amendments specified 189 pollutants, but Public Law 102-187, enacted on
December 4, 1991, deleted hydrogen sulfide from the list of toxic pollutants, leaving only
188.

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significance of residual risks, and recommend legislation regarding such risks. If
Congress does not legislate in response to EPA’s recommendations, then EPA is
required to issue standards for categories of sources of hazardous air pollutants as
necessary to protect the public health with an ample margin of safety or to prevent
an adverse environmental effect. A residual risk standard is required for any source
emitting a cancer-causing pollutant that poses an added risk to the most exposed
person of more than one-in-a-million. Residual risk standards would be due eight
years after promulgation of MACT for the affected source category. Existing sources
would have 90 days to comply with a residual risk standard, with a possible two-year
extension. In general, residual risk standards do not apply to area sources.
The law directed EPA to contract with the National Academy of Sciences
(NAS) for a study of risk assessment methodology, and created a Risk Assessment
and Management Commission to investigate and report on policy implications and
appropriate uses of risk assessment and risk management. In 1994 NAS published
its report, Science and Judgment in Risk Assessment. The Commission study,
Framework for Environmental Health Risk Management, was released in 1997.
Third, in addition to the technology-based and health-based programs for major
sources of hazardous air pollution, EPA is to establish standards for stationary “area
sources” determined to present a threat of adverse effects to human health or the
environment. The provision requires EPA to regulate the stationary area sources
responsible for 90% of the emissions of the 30 hazardous air pollutants that present
the greatest risk to public health in the largest number of urban areas. In setting the
standard, EPA can impose less stringent “generally available” control technologies,
rather than MACT.
Finally, Section 112 addresses prevention of sudden, catastrophic releases of air
toxics by establishing an independent Chemical Safety and Hazard Investigation
Board. The Board is responsible for investigating accidents involving releases of
hazardous substances, conducting studies, and preparing reports on the handling of
toxic materials and measures to reduce the risk of accidents.
EPA is also directed to issue prevention, detection, and correction requirements
for catastrophic releases of air toxics by major sources. Section 112(r) requires
owners and operators to prepare risk management plans including hazard
assessments, measures to prevent releases, and a response program.
New Source Performance Standards5
Section 111 of the Act requires EPA to establish nationally uniform,
technology-based standards (called New Source Performance Standards, or NSPS)
for categories of new industrial facilities. These standards accomplish two goals:
first, they establish a consistent baseline for pollution control that competing firms
must meet, and thereby remove any incentive for states or communities to weaken
5 This section of the report was written by Larry B. Parker, Specialist in Energy and
Environmental Policy.

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CRS-12
air pollution standards in order to attract polluting industry; and second, they preserve
clean air to accommodate future growth, as well as for its own benefits.
NSPS establish maximum emission levels for new major stationary sources —
powerplants, steel mills, and smelters, for example — with the emission levels
determined by the best “adequately demonstrated” continuous control technology
available, taking costs into account. EPA must regularly revise and update NSPS
applicable to designated sources as new technology becomes available, since the goal
is to prevent new pollution problems from developing and to force the installation of
new control technology.
The standards also apply to modifications of existing facilities, through a
process called New Source Review (NSR). The law’s ambiguity regarding what
constitutes a modification (subject to NSR) as opposed to routine maintenance of a
facility has led to litigation, with EPA recently proposing to modify its interpretation
of the requirements of this section.
Solid Waste Incinerators
Prior to 1990, solid waste incinerators, which emit a wide range of pollutants,
were subject to varying degrees of state and federal regulation depending on their
size, age, and the type of waste burned. In a new Section 129, the 1990 amendments
established more consistent federal requirements specifying that emissions of 10
categories of pollutants be regulated at new and existing incinerators burning
municipal solid waste, medical waste, and commercial and industrial waste. The
amendments also established emissions monitoring and operator training
requirements.
Prevention of Significant Deterioration / Regional Haze6
Sections 160-169 of the act establish requirements for the prevention of
significant deterioration of air quality (PSD). The PSD program reflects the principle
that areas where air quality is better than that required by NAAQS should be
protected from significant new air pollution even if NAAQS would not be violated.
The Act divides clean air areas into three classes, and specifies the increments
of SO and particulate pollution allowed in each. Class I areas include international
2
and national parks, wilderness and other pristine areas; allowable increments of new
pollution are very small. Class II areas include all attainment and not classifiable
areas, not designated as Class I; allowable increments of new pollution are modest.
Class III represents selected areas that states may designate for development;
allowable increments of new pollution are large (but not exceeding NAAQS).
Through an elaborate hearing and review process, a state can have regions
redesignated from Class II to Class III (although none have yet been so redesignated).
6 This section of the report was written by Larry B. Parker, Specialist in Energy and
Environmental Policy and James E. McCarthy, Specialist in Environmental Policy.

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CRS-13
While the 1977 amendments only stipulated PSD standards for two pollutants,
SO and particulates, EPA is supposed to establish standards for other criteria
2
pollutants. Thus far, only one of the other four (NO ) has been addressed: the agency
2
promulgated standards for NO in 1988.
2
Newly constructed polluting sources in PSD areas must install best available
control technology (BACT) that may be more strict than that required by NSPS. The
justifications of the policy are that it protects air quality, provides an added margin
of health protection, preserves clean air for future development, and prevents firms
from gaining a competitive edge by “shopping” for clean air to pollute.
In Sections 169A and B, the Act also sets a national goal of preventing and
remedying impairment of visibility in national parks and wilderness areas, and
requires EPA to promulgate regulations to assure reasonable progress toward that
goal. In the 1990 Amendments, Congress strengthened these provisions, which had
not been implemented.
The amendments required EPA to establish a Grand Canyon Visibility Transport
Commission, composed of Governors from each state in the affected region, an EPA
designee, and a representative of each of the national parks or wilderness areas in the
region. Other visibility transport commissions can be established upon EPA’s
discretion or upon petition from at least two states. Within 18 months of receiving
a report from one of these commissions, EPA is required to promulgate regulations
to assure reasonable progress toward the visibility goal, including requirements that
states update their State Implementation Plans to contain emission limits, schedules
of compliance, and other measures necessary to make reasonable progress.
Specifically mentioned is a requirement that states impose Best Available Retrofit
Technology on existing sources of emissions impairing visibility.
The Grand Canyon Commission delivered a set of recommendations to EPA in
June 1996, and the agency subsequently promulgated a “regional haze” program
applicable to all 50 states under this authority.
Acid Deposition Control7
The Clean Air Act Amendments of 1990 added an acid deposition control
program (Title IV) to the Act. It sets goals for the year 2000 of reducing annual SO2
emissions by 10 million tons from 1980 levels and reducing annual NO emissions
x
by 2 million tons, also from 1980 levels.
The SO reductions are imposed in two steps. Under Phase 1, owners/operators
2
of 111 electric generating facilities listed in the law that are larger than 100
megawatts had to meet tonnage emission limitations by January 1, 1995. This would
reduce SO emission by about 3.5 million tons. Phase 2 included facilities larger
2
than 75 megawatts, with a deadline of January 1, 2000. So far, compliance has been
100%.
7 This section of the report was written by Larry B. Parker, Specialist in Energy and
Environmental Policy.

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CRS-14
To introduce some flexibility in the distribution and timing of reductions, the
Act creates a comprehensive permit and emissions allowance system. An allowance
is a limited authorization to emit a ton of SO . Issued by EPA, the allowances would
2
be allocated to Phase 1 and Phase 2 units in accordance with baseline emissions
estimates. Powerplants which commence operation after November 15, 1990 would
not receive any allowances. These new units would have to obtain allowances
(offsets) from holders of existing allowances. Allowances may be traded nationally
during either phase. The law also permits industrial sources and powerplants to sell
allowances to utility systems under regulations to be developed by EPA. Allowances
may be banked by a utility for future use or sale.
The Act provided for two types of sales to improve the liquidity of the
allowance system and to ensure the availability of allowances for utilities and
independent power producers who need them. First, a special reserve fund consisting
of 2.8% of Phase 1 and Phase 2 allowance allocations has been set aside for sale.
Allowances from this fund (25,000 annually from 1993-1999 and 50,000 thereafter)
are sold at a fixed price of $1,500 an allowance. Independent power producers have
guaranteed rights to these allowances under certain conditions. Second, an annual,
open auction sells allowances (150,000 from 1993-1995, and 250,000 from 1996-
1999) with no minimum price. Utilities with excess allowances may have them
auctioned off at this auction, and any person may buy allowances.
The Act essentially caps SO emissions at individual existing sources through
2
a tonnage limitation, and at future plants through the allowance system. First,
emissions from most existing sources are capped at a specified emission rate times
an historic baseline level. Second, for plants commencing operation after November
15, 1990, emissions must be completely offset with additional reductions at existing
facilities beginning after Phase 2 compliance. However, as noted above, the law
provides some allowances to future powerplants which meet certain criteria. The
utility SO emission cap is set at 8.9 million tons, with some exceptions.
2
The Act provides that if an affected unit does not have sufficient allowances to
cover its emissions, it is subject to an excess emission penalty of $2,000 per ton of
SO and required to reduce an additional ton of SO the next year for each ton of
2
2
excess pollutant emitted.
The Act also requires EPA to inventory industrial emissions of SO and to report
2
every five years, beginning in 1995. If the inventory shows that industrial emissions
may reach levels above 5.60 million tons per year, then EPA is to take action under
the Act to ensure that the 5.60 million ton cap is not exceeded.
The Act requires EPA to set specific NO emission rate limitations — 0.45 lb.
x
per million Btu for tangentially-fired boilers and 0.50 lb. per million Btu for wall-
fired boilers — unless those rates can not be achieved by low-NO burner technology.
x
Tangentially and wall-fired boilers affected by Phase 1 SO controls must also meet
2
NO requirements. EPA is to set emission limitations for other types of boilers by
x
1997 based on low-NO burner costs, which EPA did. In addition, EPA is to propose
x
and promulgate a revised new source performance standard for NO from fossil fuel
x
steam generating units, which EPA also did, in 1998.

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CRS-15
Permits8
The Clean Air Act Amendments of 1990 added a Title V to the Act which
requires states to administer a comprehensive permit program for the operation of
sources emitting air pollutants. These requirements are modeled after similar
provisions in the Clean Water Act. Previously, the Clean Air Act contained limited
provision for permits, requiring only new or modified major stationary sources to
obtain construction permits (under Section 165 of the Act).
Sources subject to the permit requirements generally include major sources that
emit or have the potential to emit 100 tons per year of any regulated pollutant, plus
stationary and area sources that emit or have potential to emit lesser specified
amounts of hazardous air pollutants. However, in nonattainment areas, the permit
requirements also include sources which emit as little as 50, 25, or 10 tons per year
of VOCs, depending on the severity of the region’s nonattainment status (serious,
severe, or extreme).
States were required to develop permit programs and to submit those programs
for EPA approval by November 15, 1993. EPA had one year to approve or
disapprove a state’s submission in whole or in part. After the effective date of a state
plan, sources had 12 months to submit an actual permit application.
States are to collect annual fees from sources sufficient to cover the “reasonable
costs” of administering the permit program, with revenues to be used to support the
agency’s air pollution control program. The fee must be at least $25 per ton of
regulated pollutants (excluding carbon monoxide). Permitting authorities have
discretion not to collect fees on emissions in excess of 4,000 tons per year and may
collect other fee amounts, if appropriate.
The permit states how much of which air pollutants a source is allowed to emit.
As a part of the permit process, a source must prepare a compliance plan and certify
compliance. The term of permits is limited to no more than five years; sources are
required to renew permits at that time. State permit authorities must notify
contiguous states of permit applications that may affect them; the application and any
comments of contiguous states must be forwarded to EPA for review. EPA can veto
a permit; however, this authority is essentially limited to major permit changes. EPA
review need not include permits which simply codify elements of a state’s overall
clean air plan, and EPA has discretion to not review permits for small sources.
Holding a permit to some extent shields a source from enforcement actions: the Act
provides that a source cannot be held in violation if it is complying with explicit
requirements addressed in a permit, or if the state finds that certain provisions do not
apply to that source.
8 This section of the report was written by Claudia Copeland, Specialist in Environmental
Policy.

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CRS-16
Enforcement
Section 113 of the Act, which was also strengthened by the 1990 amendments,
covers enforcement. The section establishes federal authority to issue agency and
court orders requiring compliance and to impose penalties for violations of Act
requirements. Section 114 authorizes EPA to require sources to submit reports,
monitor emissions, and certify compliance with the Act’s requirements, and
authorizes EPA personnel to conduct inspections.
Like most federal environmental statutes, the Clean Air Act is enforced
primarily by states or local governments; they issue most permits, monitor
compliance, and conduct the majority of inspections. The federal government
functions as a backstop, with authority to review state actions. The agency may act
independently or may file its own enforcement action in cases where it concludes
that a state’s response was inadequate.
The Act also provides for citizen suits both against persons (including
corporations or government agencies) alleged to have violated emissions standards
or permit requirements, and against EPA in cases where the Administrator has failed
to perform an action that is not discretionary under the Act. Citizen groups have
often used the latter provision to compel the Administrator to promulgate regulations
required by the statute.
The 1990 Amendments elevated penalties for some knowing violations from
misdemeanors to felonies; removed the ability of a source to avoid an enforcement
order or civil penalty by ceasing a violation within 60 days of notice; gave authority
to EPA to assess administrative penalties; and authorized $10,000 awards to persons
supplying information leading to convictions under the Act.
Stratospheric Ozone Protection9
Title VI of the 1990 Clean Air Act Amendments represents the United States’
primary response on the domestic front to the ozone depletion issue. It also
implements the U.S. international responsibilities under the Montreal Protocol on
Substances that Deplete the Ozone Layer (and its amendments). Indeed, Section
606(a)(3) provides that the Environmental Protection Agency shall adjust phase-out
schedules for ozone-depleting substances in accordance with any future changes in
Montreal Protocol schedules. As a result, the phase-out schedules contained in Title
VI for various ozone-depleting compounds have now been superseded by subsequent
amendments to the Montreal Protocol.
Since passage of Title VI, depleting substances such as CFCs, methyl
chloroform, carbon tetrachloride, and halons (referred to as Class 1 substances) have
been phased out by industrial countries, including the United States. New uses of
hydrochlorofluorocarbons (HCFCs) (called Class 2 substances under Title VI) are
banned beginning January 1, 2015, unless the HCFCs are recycled, used as a
9 This section of the report was written by Larry B. Parker, Specialist in Energy and
Environmental Policy.

---

CRS-17
feedstock, or used as a refrigerant for appliances manufactured prior to January 1,
2020. Production of HCFCs is to be frozen January 1, 2015 and phased out by
January 1, 2030. Exemptions consistent with the Montreal Protocol are allowed.
The EPA is required to add any substance with an ozone depletion potential
(ODP) of 0.2 or greater to the list of Class 1 substances and set a phase-out schedule
of no more than seven years. For example, methyl bromide (ODP estimated by EPA
at 0.7) was added to the list in December 1993, requiring its phaseout by January 1,
2001; this decision was altered by Congress in 1998 to harmonize the U.S. methyl
bromide phase-out schedule with the 2005 deadline set by the parties to the Montreal
Protocol in 1997. Also, EPA is required to add any substance that is known or may
be reasonably anticipated to harm the stratosphere to the list of Class 2 substances
and set a phase-out schedule of no more than ten years.
Title VI contains several implementing strategies to avoid releases of ozone-
depleting chemicals to the atmosphere, including (1) for Class 1 substances used as
refrigerant — lowest achievable level of use and emissions, maximum recycling, and
safe disposal required by July 1, 1992; (2) for servicing or disposing refrigeration
equipment containing Class 1 and 2 substances — venting banned as of July 1, 1992;
(3) for motor vehicle air conditioners containing Class 1 or 2 substances — recycling
required by January 1, 1992 (smaller shops by January 1, 1993); (4) sale of small
containers of class 1 and 2 substances — banned within two years of enactment; and
(5) nonessential products — banned within two years of enactment.
Selected References
U.S. Environmental Protection Agency. Office of Air Quality Planning and
Standards. Air Trends. Research Triangle Park, NC. Compiled annually, and
available at [http://www.epa.gov/airtrends/].
Martineau, Robert J., Jr. and Novello, David P. (eds.). The Clean Air Act Handbook.
2nd edition. Chicago: American Bar Association, 2004. 728 p.
For current issues, see CRS Issue Brief IB10137, Clean Air Act Issues in the 109th
Congress.

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CRS-18
Table 3. Major U.S. Code Sections of the Clean Air Act10
(codified generally as 42 U.S.C. 7401-7671)
Clean Air Act,
42 U.S.C.
Section Title
as amended
Subchapter I -
Programs and Activities
Part A -
Air Quality Emissions and Limitations
7401
Findings, purpose
Sec. 101
7402
Cooperative activities
Sec. 102
7403
Research, investigation, training
Sec. 103
7404
Research relating to fuels and vehicles
Sec. 104
7405
Grants for air pollution planning and control
Sec. 105
programs
7406
Interstate air quality agencies; program cost
Sec. 106
limitations
7407
Air quality control regions
Sec. 107
7408
Air quality criteria and control techniques
Sec. 108
7409
National primary and secondary air quality
Sec. 109
standards
7410
SIPs for national primary and secondary air
Sec. 110
quality standards
7411
Standards of performance for new stationary
Sec. 111
sources
7412
Hazardous air pollutants
Sec. 112
7413
Federal enforcement
Sec. 113
7414
Recordkeeping, inspections, monitoring, and
Sec. 114
entry
7415
International air pollution
Sec. 115
7416
Retention of state authority
Sec. 116
7417
Advisory committees
Sec. 117
7418
Control of pollution from federal facilities
Sec. 118
7419
Primary nonferrous smelter orders
Sec. 119
7420
Noncompliance penalty
Sec. 120
7421
Consultation
Sec. 121
7422
Listing of certain unregulated pollutants
Sec. 122
7423
Stack heights
Sec. 123
7424
Assurance of adequacy of state plans
Sec. 124
7425
Measures to prevent economic
Sec. 125
disruption/unemployment
7426
Interstate pollution abatement
Sec. 126
7427
Public notification
Sec. 127
7428
State boards
Sec. 128
7429
Solid waste combustion
Sec. 129
7430
Emission factors
Sec. 130
7431
Land use authority
Sec. 131
10 NOTE: This tables shows only the major U.S. Code sections. For more detail and to
determine when a section was added, the reader should consult the official printed version
of the U.S. Code.

---

CRS-19
Clean Air Act,
42 U.S.C.
Section Title
as amended
Part B - Ozone Protection (repealed — new provisions related to stratospheric ozone
protection are found at 42 U.S.C. 7671 et seq., below)
Part C -
Prevention of Significant Deterioration of Air Quality
Subpart I -
Clean Air
7470
Congressional declaration of purpose
Sec. 160
7471
Plan requirements
Sec. 161
7472
Initial classifications
Sec. 162
7473
Increments and ceilings
Sec. 163
7474
Area redesignation
Sec. 164
7475
Preconstruction requirements
Sec. 165
7476
Other pollutants
Sec. 166
7477
Enforcement
Sec. 167
7478
Period before plan approval
Sec. 168
7479
Definitions Sec.
169
Subpart II -
Visibility Protection
7491
Visibility protection for federal class I areas
Sec. 169A
7492
Visibility
Sec. 169B
Part D -
Plan Requirements for Nonattainment Areas
Subpart 1 -
Nonattainment Areas in General
7501
Definitions
Sec. 171
7502
Nonattainment plan provisions in general
Sec. 172
7503
Permit requirements
Sec. 173
7504
Planning procedures
Sec. 174
7505
Environmental Protection Agency grants
Sec. 175
7505a
Maintenance plans
Sec. 175A
7506
Limitations on certain federal assistance
Sec. 176
7506a
Interstate transport commissions
Sec. 176A
7507
New motor vehicle emission standards in
Sec. 177
nonattainment areas
7508
Guidance documents
Sec. 178
7509
Sanctions and consequences of failure to attain
Sec. 179
7509a
International border areas
Sec. 179B
Subpart 2 -
Additional Provisions for Ozone Nonattainment Areas
7511
Classifications and attainment dates
Sec. 181
7511a
Plan submissions and requirements
Sec. 182
7511b
Federal ozone measures
Sec. 183
7511c
Control of interstate ozone air pollution
Sec. 184
7511d
Enforcement for Severe and Extreme ozone
Sec. 185
nonattainment areas for failure to attain
7511e
Transitional areas
Sec. 185A
7511f
NO and VOC study
Sec. 185B
x
Subpart 3 -
Additional Provisions for Carbon Monoxide Nonattainment Areas
7512
Classification and attainment dates
Sec. 186
7512a
Plan submissions and requirements
Sec. 187

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CRS-20
Clean Air Act,
42 U.S.C.
Section Title
as amended
Subpart 4 -
Additional Provisions for Particulate Matter Nonattainment Areas
7513
Classifications and attainment dates
Sec. 188
7513a
Plan provisions and schedules for plan
Sec. 189
submissions
7513b
Issuance of RACM and BACM guidance
Sec. 190
Subpart 5 -
Additional Provisions for Areas Designated Nonattainment for
Sulfur Oxides, Nitrogen Dioxide, or Lead
7514
Plan submission deadlines
Sec. 191
7514a
Attainment dates
Sec. 192
Subpart 6 -
Savings Provisions
7515
General savings clause
Sec. 193
Subchapter II -
Emission Standards for Moving Sources
Part A -
Motor Vehicle Emission and Fuel Standards
7521
Emission standards for new motor vehicles or
Sec. 202
engines
7522
Prohibited acts
Sec. 203
7523
Actions to restrain violations
Sec. 204
7524
Civil penalties
Sec. 205
7525
Motor vehicle and engines testing and
Sec. 206
certification
7541
Compliance by vehicles and engines in actual
Sec. 207
use
7542
Information collection
Sec. 208
7543
State standards
Sec. 209
7544
State grants
Sec. 210
7545
Regulation of fuels
Sec. 211
7547
Nonroad engines and vehicles
Sec. 213
7548
Study of particulate emissions from motor
Sec. 214
vehicles
7549
High altitude performance adjustments
Sec. 215
7550
Definitions
Sec. 216
7551
Study and report on fuel consumption of
Sec. 203
CAAA of 1977
7552
Motor vehicle compliance program fees
Sec. 217
7553
Prohibition on production of engines requiring
Sec. 218
leaded gasoline
7554
Urban bus standards
Sec. 219
Part B -
Aircraft Emissions Standards
7571
Establishment of standards
Sec. 231
7572
Enforcement of standards
Sec. 232
7573
State standards and controls
Sec. 233
7574
Definitions
Sec. 234
Part C -
Clean Fuel Vehicles
7581
Definitions
Sec. 241

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CRS-21
Clean Air Act,
42 U.S.C.
Section Title
as amended
7582
Requirements applicable to clean-fuel vehicles
Sec. 242
7583
Standards for light-duty clean-fuel vehicles
Sec. 243
7584
Administration and enforcement as per
Sec. 244
California standards
7585
Standards for heavy-duty clean-fuel vehicles
Sec. 245
7586
Centrally fueled fleets
Sec. 246
7587
Vehicle conversions
Sec. 247
7588
Federal agency fleets
Sec. 248
7589
California pilot test program
Sec. 249
7590
General provisions
Sec. 250
Subchapter III -
General Provisions
7601
Administration
Sec. 301
7602
Definitions
Sec. 302
7603
Emergency powers
Sec. 303
7604
Citizen suits
Sec. 304
7605
Representation in litigation
Sec. 305
7606
Federal procurement
Sec. 306
7607
Administrative proceedings and judicial review
Sec. 307
7608
Mandatory licensing
Sec. 308
7609
Policy review
Sec. 309
7610
Other authority
Sec. 310
7611
Records and audits
Sec. 311
7612
Economic impact analyses
Sec. 312
7614
Labor standards
Sec. 314
7615
Separability
Sec. 315
7616
Sewage treatment plants
Sec. 316
7617
Economic impact assessment
Sec. 317
7619
Air quality monitoring
Sec. 319
7620
Standardized air quality modeling
Sec. 320
7621
Employment effects
Sec. 321
7622
Employee protection
Sec. 322
7624
Cost of vapor recovery equipment
Sec. 323
7625
Vapor recovery for small business marketers of
Sec. 324
petroleum products
7625-1
Exemptions for certain territories
Sec. 325
7625a
Statutory construction
Sec. 326
7626
Authorization of appropriations
Sec. 327
7627
Air pollution from Outer Continental Shelf
Sec. 328
activities
Subchapter IV-A Acid Deposition Control
7651
Findings and purposes
Sec. 401
7651a
Definitions
Sec. 402
7651b
Sulfur dioxide allowance program for existing
Sec. 403
and new units
7651c
Phase I sulfur dioxide requirements
Sec. 404
7651d
Phase II sulfur dioxide requirements
Sec. 405
7651e
Allowances for states with emissions rates at or
Sec. 406
below 0.80 lbs./mmBtu

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CRS-22
Clean Air Act,
42 U.S.C.
Section Title
as amended
7651f
Nitrogen oxides emission reduction program
Sec. 407
7651g
Permits and compliance plans
Sec. 408
7651h
Repowered sources
Sec. 409
7651i
Election for additional sources
Sec. 410
7651j
Excess emissions penalty
Sec. 411
7651k
Monitoring, reporting, and recordkeeping
Sec. 412
requirements
7651l
General compliance with other provisions
Sec. 413
7651m
Enforcement
Sec. 414
7651n
Clean coal technology regulatory incentives
Sec. 415
7651o
Contingency guarantee, auctions, reserve
Sec. 416
Subchapter V -
Permits
7661
Definitions
Sec. 501
7661a
Permit programs
Sec. 502
7661b
Permit applications
Sec. 503
7661c
Permit requirements and conditions
Sec. 504
7661d
Notification to administrator and contiguous
Sec. 505
states
7661e
Other authorities
Sec. 506
7661f
Small business stationary source technical and
Sec. 507
environmental compliance assistance program
Subchapter VI -
Stratospheric Ozone Protection
7671
Definitions
Sec. 601
7671a
Listing of class I and class II substances
Sec. 602
7671b
Monitoring and reporting requirements
Sec. 603
7671c
Phase-out of production and consumption of
Sec. 604
class I substances
7671d
Phase-out of production and consumption of
Sec. 605
class II substances
7671e
Accelerated schedule
Sec. 606
7671f
Exchange authority
Sec. 607
7671g
National recycling and emission reduction
Sec. 608
program
7671h
Servicing of motor vehicle air conditioners
Sec. 609
7671i
Nonessential products containing
Sec. 610
chlorofluorocarbons
7671j
Labeling
Sec. 611
7671k
Safe alternatives policy
Sec. 612
7671l
Federal procurement
Sec. 613
7671m
Relationship to other laws
Sec. 614
7671n
Authority of Administrator
Sec. 615
7671o
Transfers among parties to Montreal Protocol
Sec. 616
7671p
International cooperation
Sec. 617
7671q
Miscellaneous provisions
Sec. 618
[29 U.S.C. 655]
Chemical Process Safety Management
Sec. 304 of CAA
of 1990
[29 U.S.C. 1662e] Clean Air Employment Transition Assistance
Sec.1101 of
CAA of 1990

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