Dioxin and dioxin-like compounds data are reported on the TRI Reporting Form R Schedule 1. There are seventeen distinct members of this chemical category listed under TRI. In addition to the total grams released for the entire category, facilities must report the quantity for each individual member.

Although useful, total releases are not the best measure of the actual toxicity of these compounds because each compound has its own level of toxicity. To account for how 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). TEQs allow for a better understanding of the toxicity of releases and waste management activities at facilities that report to the TRI Program.

The data contained in these files are presented in comma delimited ASCII text bundled into a .zip format. For more information about using these files, see the TRI TEQ Data Files Guide (PDF).