shall not include motor vehicles or nonroad vehicles subject to regulation under title II.

(3) STATIONARY SOURCE.-The term "stationary source" shall have the same meaning as such term has under section 111(a).

(4) NEW SOURCE.-The term "new source" means a stationary source the construction or reconstruction of which is commenced after the Administrator first proposes regulations under this section establishing an emission standard applicable to such source.

(5) MODIFICATION.-The term "modification" means any physical change in, or change in the method of operation of, a major source which increases the actual emissions of any hazardous air pollutant emitted by such source by more than a de minimis amount or which results in the emission of any hazardous air pollutant not previously emitted by more than a de minimis amount.

(6) HAZARDOUS AIR POLLUTANT.-The term "hazardous air pollutant" means any air pollutant listed pursuant to subsection (b).

(7) ADVERSE ENVIRONMENTAL EFFECT.-The term "adverse environmental effect" means any significant and widespread adverse effect, which may reasonably be anticipated, to wildlife, aquatic life, or other natural resources, including adverse impacts on populations of endangered or threatened species or significant degradation of environmental quality over broad

areas.

(8) ELECTRIC UTILITY STEAM GENERATING UNIT.—The term "electric utility steam generating unit" means any fossil fuel fired combustion unit of more than 25 megawatts that serves a generator that produces electricity for sale. A unit that cogenerates steam and electricity and supplies more than onethird of its potential electric output capacity and more than 25 megawatts electrical output to any utility power distribution system for sale shall be considered an electric utility steam generating unit.

(9) OWNER OR OPERATOR.-The term "owner or operator" means any person who owns, leases, operates, controls, or supervises a stationary source.

(10) EXISTING SOURCE.-The term "existing source" means any stationary source other than a new source.

(11) CARCINOGENIC EFFECT.-Unless revised, the term "carcinogenic effect" shall have the meaning provided by the Administrator under Guidelines for Carcinogenic Risk Assessment as of the date of enactment. 1 Any revisions in the existing Guidelines shall be subject to notice and opportunity for comment.

(b) LIST OF POLLUTANTS.

1

(1) INITIAL LIST.-The Congress establishes for purposes of this section a list of hazardous air pollutants as follows:

So in original. Probably refers to the date of enactment of Public Law 101-549 (Nov. 15,

72435 Methoxychlor

74839 Methyl bromide (Bromomethane)

74873 Methyl chloride (Chloromethane)

71556 Methyl chloroform (1,1,1-Trichloroethane)

78933 Methyl ethyl ketone (2-Butanone)

60344 Methyl hydrazine

74884 Methyl iodide (Iodomethane)

108101 Methyl isobutyl ketone (Hexone)

624839 Methyl isocyanate

80626 Methyl methacrylate

1634044 Methyl tert butyl ether

101144 4,4-Methylene bis(2-chloroaniline)

75092 Methylene chloride (Dichloromethane)

101688 Methylene diphenyl diisocyanate (MDI)

101779 4,4'-Methylenedianiline

91203 Naphthalene

98953 Nitrobenzene 92933 4-Nitrobiphenyl

100027 4-Nitrophenol 79469 2-Nitropropane

684935 N-Nitroso-N-methylurea

62759 N-Nitrosodimethylamine

59892 N-Nitrosomorpholine

NOTE: For all listings above which contain the word "compounds" and for glycol ethers, the following applies: Unless otherwise specified, these listings are defined as including any unique chemical substance that contains the named chemical (i.e., antimony, arsenic, etc.) as part of that chemical's infrastructure.

1X'CN where X = H' or any other group where a formal dissociation may occur. For example KCN or Ca(CN)2

2 Includes mono- and di- ethers of ethylene glycol, diethylene glycol, and triethylene glycol R(OCH2CH2),-OR' where

n = 1, 2, or 3

R = alkyl or aryl groups

R' = R, H, or groups which, when removed, yield glycol ethers with the structure: R(OCH2CH),-OH. Polymers are excluded from the glycol category.

3 Includes mineral fiber emissions from facilities manufacturing or processing glass, rock, or slag fibers (or other mineral derived fibers) of average diameter 1 micrometer or less.

* Includes organic compounds with more than one benzene ring, and which have a boiling point greater than or equal to 100°C.

5 A type of atom which spontaneously undergoes radioactive decay.

(2) REVISION OF THE LIST.-The Administrator shall periodically review the list established by this subsection and publish the results thereof and, where appropriate, revise such list by rule, adding pollutants which present, or may present, through inhalation or other routes of exposure, a threat of adverse human health effects (including, but not limited to, 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 adverse environmental effects whether through ambient concentrations, bioaccumulation, deposition, or otherwise, but not including releases subject to regulation under subsection (r) as a result of emissions to the air. No air pollutant which is listed under section 108(a) may be added to the list under this section, except that the prohibition of this sentence shall not apply to any pollutant which independently meets the listing criteria of this paragraph and is a precursor to a pollutant which is listed under section 108(a) or to any pollutant which is in a class of pollutants listed under such section. No substance, practice, process or activity regulated under title VI of this Act shall be subject to regulation under this section solely due to its adverse effects on the environment.

(3) PETITIONS TO MODIFY THE LIST.—

(A) Beginning at any time after 6 months after the date of enactment of the Clean Air Act Amendments of 1990, any person may petition the Administrator to modify the list of hazardous air pollutants under this subsection by adding or deleting a substance or, in case of listed pollutants without CAS numbers (other than coke oven emissions, mineral fibers, or polycyclic organic matter) removing certain unique substances. Within 18 months after receipt of a petition, the Administrator shall either grant or deny the petition by publishing a written explanation of the reasons for the Administrator's decision. Any such petition shall include a showing by the petitioner that there is adequate data on the health or environmental defects 1 of the pollutant or other evidence adequate to support the

1 So in original. Probably should be “effects".