An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to 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 This website is no longer updated and links to external websites and some internal pages may not work.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 »

Air Emissions Inventories

SPECIATE's VOC and PM Speciation Profiles and Their use to Prepare for Air quality Modeling (2017 EIC)

This training provides general concepts on chemical speciation, the SPECIATE database and browser, and how to use the Speciation Tool to create model ready speciation inputs for a photochemical air quality model.  

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.