"TM-17" denotes the "total mass" of the 17 dioxin compounds of interest in any given sample of dioxin. Dioxins almost always occur as a complex mixture of individual compounds. The EPA requires facilities to report the 2000 TRI dioxin data in units of total grams, or grams-TM-17 (g-TM17).

"TM-17" reporting is different from "TEQ" reporting of dioxin quantities. The TEQ method is a toxicity-weighted reporting method whereby the masses of individual dioxin compounds are scaled by Toxic Equivalency Factors (TEFs). Unlike the TM-17 method, the TEQ method offers meaningful information about the total toxicity of a dioxin sample. Dioxins commonly are reported using the TEQ method. The US EPA lists dioxin quantities in grams-TEQ in its Inventory of Sources of Dioxin in the United States. Click here for a complete description of TEQ reporting.

Click here for individual facility data

Click here for TRI press release, Toxics Release Inventory Demonstrates Chlorine Industry Success in Managing Dioxin