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  2. Air Emissions Factors and Quantification

Final Revisions to AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks - 2024

Introduction

This final section presents procedures 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.

AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks

The final version of AP-42 Chapter 7, Section 1 can be found here:

Final AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks (pdf) (13.72 MB)

Summary of Changes Final AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks (pdf) (178.34 KB)

Final AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks RLSO (pdf) (7.19 MB)

Public Comments and Response to Comments 

Response to Comments - TANKS 5.0 and AP-42 Chapter 7, Section 1 (pdf) (838.23 KB)  

Drafted Chapter 7, Section 1 - Organic Liquid Storage Tanks Revised Documents

Draft AP-42 Chapter 7, Section 7.1 - Organic Liquid Storage Tanks (pdf) (5.11 MB)

Red Line Strike Out Draft AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks (pdf) (6.85 MB)

Summary of Changes Draft AP-42 Chapter 7, Section 1 - Organic Liquid Storage Tanks (pdf) (127.87 KB)

TANKS 5.1

EPA has released TANKS 5.1. The TANKS 5.1 application is located here: https://TANKS.app.cloud.gov. More information can be found here: https://www.epa.gov/air-emissions-factors-and-quantification/tanks-emissions-estimation-software-version-5. To receive notifications related to application updates, sign up for the CHIEF Listserv by sending an e-mail to join-chief@lists.epa.gov. 

The TANKS 5.1 User Guide (pdf) (870.8 KB) explains each screen and defines the parameters entered into TANKS 5.1. 

Air Emissions Factors and Quantification

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Last updated on March 25, 2025
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