The U.S. Environmental Protection Agency (EPA) announced a final rule on May 10 to increase reporting of dioxin compounds, some of the most potent carcinogens, under the Toxics Release Inventory (TRI) program.

In accordance with the Emergency Planning and Community Right-to-Know Act (EPCRA) of 1986, all facilities have been required to report the combined amount of seventeen dioxin and dioxin-like compounds that are released or transferred from a facility. EPA is now expanding the reporting to include requirements that facilities report on each compound individually, beginning June 9. Such detailed reporting will enable EPA to more accurately track the toxicity of dioxin releases at a facility, as the different compounds have varying levels of toxicity. This "toxic equivalent" (TEQ) — a weighted toxic value using the most toxic compound as a baseline — provides a more accurate and useful comparison of facility releases. The new reporting should also allow communities to better determine the level of risk posed from dioxin and dioxin-like compounds released in their area.

Dioxins, unintentional byproducts of combustion and industrial chemical processes, are extremely toxic and mobile. Typically released as airborne pollution, they often contaminate air, soil, sediments and food, causing cancer, reproductive problems, and developmental delays. Not naturally found in the environment, dioxins are entirely a human creation with no known "safe" level. TRI requires disclosure of any release greater than a single gram, as opposed to the five-thousand pound threshold of other toxic chemicals. In 2005, more than 1,200 facilities released or disposed of approximately 84,500 grams, or 186 pounds, of dioxin compounds.

While this increased specificity in dioxin reporting is an improvement, it seems a very minor advance in the face of the larger rollbacks promulgated by EPA's December 2006 rule change, which reduced reporting on more than 600 other chemicals tracked under TRI. The December rule raised the reporting threshold for most chemicals from 500 pounds to 5,000 pounds, of which up to 2,000 pounds can be released directly to the environment.