Air Emissions Factors and Quantification

  • What is an emission factor?

    An emissions factor is a representative value that attempts to relate the quantity of a pollutant emitted with an industrial activity.

Emissions factors are tools for building emissions inventories, guiding air quality management decisions and developing emissions control strategies.  

Alerts

10/13/2026 - EPA has drafted new emission factors for AP-42 Chapter 4, Section 12 – Manufacture of Rubber Products. These factors can be found on the Draft Revisions to AP-42 Chapter 4, Section 12 – Manufacture of Rubber Products page. Comments will be accepted through 12/12/2026.

Air Emissions Factors / AP-42

Web Factor and Information Retrieval System (WebFIRE)

See also Clearinghouse for Inventories and Emissions Factors (CHIEF)

Contact Us about Air Emissions Factors to ask a question, provide feedback, or report a problem.
Last updated on October 13, 2026