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This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »
Join the CHIEF Listserv to receive information about new emissions factors, conferences, updates to software tools and related information by contacting join-chief@lists.epa.gov.
Emissions factors are tools for building emissions inventories, guiding air quality management decisions and developing emissions control strategies. This technical website provides current information on these tools and provides support for using them.