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 This website is no longer updated and links to external websites and some internal pages may not work.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 »

Ambient Monitoring Technology Information Center (AMTIC)

Air Monitoring Methods - Criteria Pollutants

These documents support the EPA program for approving Federal Reference Methods (FRM) and Federal Equivalent Methods (FEMs). This information will be updated periodically based on input from EPA’s Office of Research and Development.

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