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 This website is no longer updated and links to external websites and some internal pages may not work.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

Toxics Release Inventory (TRI) Program

2010 Dioxin and Dioxin-like Compounds and TEQ Data Files

Six data files represent all of the Toxics Release Inventory (TRI) dioxin and dioxin-like compounds data for reporting year 2010, including toxic equivalency (TEQ) data. There are seventeen distinct members of this chemical category listed under TRI. In addition to the total quantity (in grams) released for the entire dioxin category, facilities must report the quantity for each individual member. Dioxin data are reported on the TRI Form R Schedule 1.

Although useful, the total quantity of releases is not the best measure of the actual toxicity of dioxin and dioxin-like compounds because each compound has a different level of toxicity. To account for how these compounds vary in toxicity, EPA calculates weighted values called toxic equivalents (TEQs) from the individual mass quantity data reported by facilities and the associated Toxic Equivalency Factors (TEFs).

For detailed descriptions of the contents of these files, please see Guidance for Using Historical TRI Dioxin and Dioxin-like Compounds Data Files.

The types of TRI Dioxin and Dioxin-like Compounds and TEQs Data Files include:

Note: Quantities of dioxin and dioxin-like compounds are reported in grams, while all other chemicals are reported in pounds.