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TRI Dioxin and Dioxin-like Compounds Toxic Equivalency Reporting Rule - Proposed Rule

EPA is proposing revisions to the reporting requirements for the Toxics Release Inventory (TRI) dioxin and dioxin-like compounds category. There are seventeen distinct members of this chemical category listed under TRI. EPA currently requires that facilities report, in grams, the total amount of dioxin and dioxin-like compounds released from the facility. When available, the facility must also provide a single “distribution,” showing how that total is divided among the individual dioxin and dioxin-like compounds. This single distribution must represent either total releases, or releases to the media (air, land, water) for which the facility has the best information.

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, we use a weighted value called toxic equivalents (TEQs). To calculate TEQs, we assign a value describing how toxic each dioxin and dioxin-like compound is compared to the most toxic members of the category: 2,3,7,8-tetrachlorodibenzo-p-dioxin and 1,2,3,7,8-pentachlorodibenzo-p-dioxin.

Expressing data for dioxin and dioxin-like compounds as TEQs allows the public to understand the toxicity of releases and waste management at facilities that report under the TRI program. For example, a facility releasing 3 grams of some combination of dioxin and dioxin-like compounds may or may not be of greater interest than a facility releasing 1 gram of a different combination. However, a facility releasing 3 grams TEQ of dioxins is of greater environmental importance than one releasing 1 gram TEQ to the same environmental medium (e.g., air).

TEQs will allow the public to make more informed environmental decisions within their communities. Expressing dioxin releases and waste management information in grams TEQ will also permit easier comparisons between TRI data and other EPA and international data.

The proposal contains three options. Each would require reporting of TEQs or information that can be used to calculate TEQs, for each member of the chemical category, in addition to the total grams released for the entire category. Each would also remove the requirement to report the single distribution of compounds in the category. The two preferred options (options two and three) would replace that distribution with reporting of the mass quantity of each individual member of the category; they differ primarily in whether the Agency or the facility would perform TEQ computations. Option one would not require reporting of releases for each compound in the category.

The proposal would also require that all reports for dioxin and dioxin-like compounds be filed electronically on a new Form R-D.

TRI Dioxin and Dioxin-like Compounds Toxic Equivalency Proposed Rule (PDF) - Federal Register Notice: 70 Federal Register 10919, March 7, 2005

Comments on the proposed rule are due to EPA by May 6, 2005. Further information on this proposed rule, including how to submit comments, is available from the following:

Q: What are dioxin and dioxin-like compounds?

A: Dioxin and dioxin-like compounds are trace level unintentional byproducts of some forms of combustion and several industrial chemical processes. They are not commercial chemical products.

Dioxins are transported primarily through the air and are deposited on surfaces; they have been detected in air, soil, sediments and food.

The principal route by which dioxins are introduced to most rivers, streams and lakes is soil erosion and storm water runoff from urban areas. Industrial discharges can significantly elevate water concentrations near the point of discharge to rivers and streams. Major contributors of dioxin to the environment include:

Backyard burning of household waste may also be an important source.

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Q: What is a TEQ and how is it calculated?

A: TEQs are a calculated value that allow us to compare the toxicity of different combinations of dioxins and dioxin-like compounds. The two most toxic compounds are the comparison point. For example, a mixture weighing 10g with a TEQ of 5g would be as toxic as 5g of either of those compounds.

In order to calculate a TEQ, a toxic equivalent factor (TEF) is assigned to each member of the dioxin and dioxin-like compounds category. The TEF is the ratio of the toxicity of one of the compounds in this category to the toxicity of the two most toxic compounds in the category, which are each assigned a TEF of 1: 2,3,7,8-tetrachlorodibenzo-p-dioxin (commonly referred to as dioxin) and 1,2,3,7,8-pentachlorodibenzo-p-dioxin. TEFs that have been established through international agreements currently range from 1 to 0.0001.

A TEQ is calculated by multiplying the actual grams weight of each dioxin and dioxin-like compound by its corresponding TEF (e.g., 10 grams X 0.1 TEF = 1 gram TEQ) and then summing the results. The number that results from this calculation is referred to as grams TEQ.

For example, consider the following 60g mixture:
10g of compound A, with a TEF of 1
20g of compound B, with a TEF of 0.5
30g of compound C, with a TEF of 0.2.

The TEQ of this mixture would be:
(10g x 1) + (20g x 0.5) + (30g x 0.2) = 26g TEQ,

In other words, this mixture of 60g of various compounds would be as toxic as 26g of either of the two most toxic compounds.

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Q: Why are TEQs useful? What are their drawbacks?

A: Using TEQs helps people understand the relative toxicity of the chemical release information. For example, it is not possible to conclude that two facilities, each releasing 2 grams of dioxin and dioxin-like compounds are of equal environmental importance without considering other factors. It may be possible, however, to conclude that two facilities each releasing 2 grams TEQ are of equal importance if the releases from each facility are to the same environmental medium (e.g., air)

On the other hand, it is not possible on the basis of TEQ alone to establish whether the two sources are making equal strides in release or waste minimization. Instead, it is necessary to know the actual mass of each compound that is released.

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Q: What changes is EPA proposing for the reporting for the dioxin and dioxin-like compounds category under TRI?

A: EPA is proposing to require reporting of TEQ data and/or the individual grams data for each member of the category for each release, by medium, and each waste management process, in addition to the total category grams data currently reported. In addition, EPA is proposing that all facilities report using a new Form R-D specifically developed for reporting dioxin and dioxin-like compounds, and that all Form R-Ds be filed electronically. EPA is also proposing to eliminate the current requirement to report a single distribution for the dioxin and dioxin-like compounds category, since this information will be redundant when today’s proposal is finalized.

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Q: Why is EPA proposing these changes to the reporting for dioxin and dioxin-like compounds?

A: The addition of TEQ reporting will allow further understanding of the releases and waste management quantities currently reported to the TRI for dioxin and dioxin-like compounds. In addition, TEQs make it easier to compare TRI data with other EPA data and international data.

EPA is proposing these revisions in response to requests from TRI reporters that EPA provide facilities with a method of reporting TEQ data to provide important context for dioxin release data. In addition, EPA believes that the public will benefit from the additional context and comparability of data provided by TEQ reporting.

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Q: If TEQs are the product of a simple mathematical formula using grams of weight multiplied by toxic equivalent factors assigned by the international scientific community, why doesn’t EPA just calculate the TEQs in-house rather than requiring reporters to provide that information?

A: The TRI data currently reported for dioxin and dioxin-like compounds are not detailed enough to use to calculate TEQ data specific to each release or waste management activity. In order for the facility or EPA to do TEQ calculations, the grams data for each individual member of the category must be available for each release or waste management practice. Two of the three options would include TEQ reporting, but one option in the proposed rule would have facilities report just the individual grams data and then EPA would calculate the TEQ data. Though EPA could, and would intend to, report TEQs alongside the reported data, there would be no regulatory or statutory requirement for it to do so. Consequently we are seeking comment on the reasons why such an option could be beneficial and what, if any, concerns, the public would have about such a decision.

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Q: Why is EPA proposing to require facilities that report releases and waste management for dioxin and dioxin-like compounds to report these numbers electronically when the same information can be reported on paper for other chemicals?

A: In order to capture the individual grams data for each member of the category for each release and waste management activity, the proposed Form R-D will include many more data elements than are reported for other chemicals, which will increase the possibility for errors when EPA has to transfer data to the TRI database from hard copy reports. Requiring all Form R-Ds to be submitted electronically will result in less preparation error and fewer processing errors than are associated with paper submissions. As EPA stated in a recent letter to TRI reporting facilities, EPA has an ongoing effort to modernize and streamline the TRI program. One goal of the modernization effort is to process all reporting forms via the Internet utilizing EPA's Central Data Exchange (CDX). Requiring that all Form R-D reports be submitted electronically, which includes submissions via CDX or diskette, would be one small step toward the ultimate goal of full Internet reporting.

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Q:Will TEQ data be available for all reports of releases and waste management data for dioxin and dioxin-like compounds when the proposal is finalized?

A: TRI reporters are not required to collect new data or undertake monitoring for use in completing Form Rs or Form A Certification Statements, and will not be required to do so to complete the new Form R-D. Instead, facilities use the best information they have available or estimate information to be reported.

For reporting year 2001, there were 1,315 facilities that filed Form Rs for dioxin and dioxin-like compounds. Of these facilities, 70 percent (920 facilities) completed section 1.4 of the Form R containing distribution information on the members of the category. The 395 facilities that did not complete section 1.4 are unlikely to be able to provide individual grams data for each member of the category and therefore are unlikely to be able to calculate a TEQ value or provide EPA sufficient information that EPA could calculate a TEQ value.

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Q: How much will the change in reporting requirements cost?

A: The total incremental cost to industry for the proposed option that requires industry to report both individual grams data and TEQ data is estimated at $170,030 in the first reporting year and $92,392 in subsequent reporting years. All other options discussed in the proposal would cost less. For example, the option under which EPA would calculate the TEQ data is estimated at $122,687 in the first reporting year and $45,049 in subsequent reporting years.

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Q: Who has to report releases and other waste management information for dioxin and dioxin-like compounds?

A: Any facilities in specified Standard Industrial Codes (SIC ) codes with 10 or more employees that exceed the reporting thresholds for dioxin and dioxin-like compounds and meet the other TRI reporting criteria must file a report. The individual sectors and facilities reporting on the TRI dioxin and dioxin-like compounds category will not change as a result of this proposed rule.

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Q: How can I get more background on EPA’s TRI Program and the proposed rule?

A: This information is available:

• on our Web site (http://www.epa.gov/tri/tridata/teq/teqmodfrule.html)
• by calling an EPA representative, or
• by contacting the Emergency Planning and Community Right-to-Know hotline (toll-free) 1-800-424-9346 or (toll-free) TDD: 1-800-553-7672.

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