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Air Emissions Factors and Quantification

Older Editions of AP 42, Compilation of Air Pollutant Emission Factors

The AP 42, Compilation of Air Pollutant Emission Factors, was first published by the US Public Health Service in 1968. The first through fourth editions, including supplements, are available below. In September 1985, the fourth edition was split into two volumes. Volume I includes stationary point and area source emission factors, and Volume II includes mobile source emission factors. Volume II is available on the the EPA's Office of Transportation & Air Quality web site.

This information is available for historical purposes only. For the most recent emission factors, supported by the EPA, please go to the current AP 42 web site.

The files are scanned images and have been converted to Acrobat PDF.

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

First editions, AP 42, US EPA
Compilation of Air Pollutant Emission Factors, 1968 (PDF) (76 pp, 2 MB) Environmental Health Series, US Public Health Service
Compilation of Air Pollutant Emission Factors, 1971 (PDF) (184 pp, 7 MB) Preliminary Document, US EPA
Compilation of Air Pollutant Emission Factors, 1972 (PDF) (170 pp, 9 MB) Revised, US EPA


Second edition, AP 42, US EPA
Compilation of Air Pollutant Emission Factors - Second edition, 1973 (PDF) (305 pp, 10 MB)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 1, July 1973 (PDF) (28 pp, 1 MB)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 2, September 1973 (PDF) (20 pp, 765 K)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 3, May 1974 (PDF) (60 pp, 3 MB)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 4, January 1975 (PDF) (75 pp, 3 MB)
Compilation of Air Pollutant Emission Factors - Second edition with supplements 1-4, 1975 (PDF) (390 pp, 14 MB)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 5, December 1975 (PDF) (166 pp, 7 MB)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 6, April 1976 (PDF) (62 pp, 3 MB)
Compilation of Air Pollutant Emission Factors - Second edition, supplement 7, April 1977 (PDF) (128 pp, 5 MB)


Third edition, AP 42, US EPA
Compilation of Air Pollutant Emission Factors - Third edition including supplements 1- 7 from second edition, 1977 (PDF) (548 pp, 21 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 8, 1978 (PDF) (116 pp, 5 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 9, 1979 (PDF) (228 pp, 7 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 10, February 1980 (PDF) (162 pp, 6 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 11, October 1980 (PDF) (95 pp, 4 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 12, 1981 (PDF) (184 pp, 6 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 13, 1982 (PDF) (132 pp, 5 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 14, 1983 (PDF) (182 pp, 7 MB)
Compilation of Air Pollutant Emission Factors - Third edition, supplement 15, 1984 (PDF) (94 pp, 4 MB)
Compilation of Air Pollutant Emission Factors - Third edition, Update package, 1985 (PDF) (94 pp, 4 MB)
Fourth edition, Volume I: Stationary Point and Area Sources, AP 42, US EPA Compilation of Air Pollutant Emission Factors, - Fourth Edition, 1985 (PDF) (874 pp, 29 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, supplement A, 1986 (PDF) (484 pp, 14 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, supplement B, 1988 (PDF) (188 pp, 7 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, supplement C, 1990 (PDF) (161 pp, 6 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, supplement D, 1991 (PDF) (144 pp, 6 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, supplement E, 1992 (PDF) (281 pp, 9 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, supplement F, 1993 (PDF) (630 pp, 23 MB)
Compilation of Air Pollutant Emission Factors - Fourth Edition, with supplements A through F incorporated, (1985 to 1993) (PDF) (1809 pp, 62 MB)


Fifth edition, Volume I: Stationary Point and Area Sources, AP 42, US EPA
*Most sections in the 5th edition have been updated. The most recent supplements are available on the the AP42 webpage.
Compilation of Air Pollutant Emission Factors, - Fifth Edition, 1995 (PDF) (1998 pp, 74 MB)