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Air Emissions Factors and Quantification

Final Revisions to AP-42 Chapter 7, Section 7.1 - Organic Liquid Storage Tanks


This section presents models for estimating air emissions from organic liquid storage tanks. It also contains detailed descriptions of typical varieties of such tanks, including horizontal, vertical, and underground fixed roof tanks, and internal and external floating roof tanks.

The emission estimation equations presented herein have been developed by the American Petroleum Institute (API), which retains the legal right to these equations. API has granted EPA permission for the nonexclusive, noncommercial distribution of this material to governmental and regulatory agencies.  However, API reserves its rights regarding all commercial duplication and distribution of its material. Hence, the material presented is available for public use, but it cannot be sold without written permission from both the American Petroleum Institute and the U. S. Environmental Protection Agency.

The major pollutant of concern is volatile organic compounds. There also may be speciated organic compounds that may be toxic or hazardous.

Chapter 7, Section 7.1 - Organic Liquid Storage Tanks

The link to Chapter 7, Section 7.1 of AP-42 can be found here: 

AP-42 Chapter 7, Section 7.1: Organic Liquid Storage Tanks June, 2020.

Chapter 7 Updates  (4 pp, 221 K) March 2020

Public Comments and Response to Comments

Comments were received during the comment period of July 25, 2018 to November 26, 2018.

Public comments for Chapter 7, Section 7.1  February 2019 (66 pp, 4 MB)

Response to Comments for Chapter 7, Section 7.1 November 2019 (39 pp, 609 K)

Proposed Revised Documents

Proposed AP-42 Chapter 7, Section 7.1  July 25, 2018 (196 pp, 5 MB)

Proposed AP-42 Chapter 7, Section 7.1 revisions: Organic Liquid Storage Tanks (redline strikeout version)  July 25, 2018 (211 pp, 5 MB)

Proposed AP-42 Chapter 7, Section 7.1 revisions summary  July 25, 2018 (27 pp, 470 K)