The Clean Air Act
United States Congress / 1970 / on the adoption of its provisions and amendments
Federal law with binding character in all United States of America
The Clean Air Act is a law that regulates air emissions form stationary and mobile sources in order to insure proper air quality. It addresses a wide range of factors that may affect air quality: chemical pollutants, noise, particulate matter, tropospheric ozone precursors and stratospheric ozone depleting substances, clean fuels etc.
The Act establishes a list of hazardous pollutants that includes substances ”which are known to be, or may reasonably be anticipated to be, carcinogenic, mutagenic, teratogenic, neurotoxic, which cause reproductive dysfunction, or which are acutely or chronically toxic” or have ”adverse environmental effects whether through ambient concentrations, bioaccumulation, deposition, or otherwise”.
The law provides the framework for establishing Ambient Air Quality Standards at national level and for the transposition of these standards at local (state) level.
In the case of stationary sources with high level of emissions per year (“major sources”) the Environmental Protection Agency establishes ”standards that require the maximum degree of reduction in emissions of hazardous air pollutants”. Such standards should include substitution of ”hazardous materials” as a measure for “maximum achievable control technology”.
The Clean Air Act has been amended in 1977, 1990 and 2004. This presentation refers to the latest edition.
In Section 112 ”Hazardous air pollutants” is stated that emission standards applicable to new or existing sources of hazardous air pollutants shall require the maximum degree of reduction or elimination of such pollutants ”through process changes, substitution of materials or other modifications”. Paragraph (n,3) refers to applying such measures to publicly owned treatment works.
Section 183 refers to federal measures for tropospheric ozone and defines ”best available controls” that should include “chemical reformulation, product or feedstock substitution” as means to reduce emissions of substances that contribute to ozone formation.
Section 608 refers to stratospheric ozone depleting substances. The Environmental Protection Agency shall promulgate regulations establishing standards and requirements regarding the use and disposal of substances that are most hazardous for the stratospheric ozone layer. Such measures may include requirements to use alternative substances and/or to promote the use of such safer alternatives.
Section 612 ”Safe alternatives policy” also refers to the substances causing stratospheric ozone depletion. According to it, the most hazardous such substances (class I and II) shall be subject to measures like “replaced chemicals, product substitutes, or alternative manufacturing process”. Federal research facilities should assist users in identifying and developing alternatives to the use of such substances in solvents, fire retardants, foam blowing agents, and other commercial applications and in achieving a transition to such alternatives. The Environmental Protection Agency shall prevent using unsafe substitutes by publishing a list of prohibited substitutes and another list of safe alternatives identified for specific uses. Moreover, substitutes for some of these substances (class I) need to undergo an assessment and a notification procedure.
Section 613 expands legal provisions regarding ozone depleting substances to federal procurement. According to this Section important federal institutions (like the General Services Administration and the Secretary of Defense) shall ”promulgate regulations requiring each department, agency, and instrumentality of the United States to conform its procurement regulations to the policies and requirements of this title and to maximize the substitution”.
The law has provisions regarding substitution measures whenever chemical pollutants are concerned. The systematic requirement of safer alternatives and the involvement of federal resources and institutions in research activities and in supporting transition to such alternatives illustrate the importance given to substitution. Substitution measures are not limited to substance by substance replacement but include also process changes. The procurement process should also take into account substitution of hazardous substances, in particular of those that are known to endanger the stratospheric ozone layer (a very actual environmental problem at the time of the Act publication).
Clean Air Act Timeline – short presentation of the Act’s achievements and failures
The Plain English Guide to the Clean Air Act by EPA
Summary of the Clean Air Act by EPA
Last update: 21.02.2010