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Toxic Equivalence (TEQ): TEQ is the product of the concentration of an individual DLC in an environmental mixture and its corresponding TCDD TEF for that compound. vii
The “Toxic Equivalent” (TEQ) scheme weighs the toxicity of the less toxic compounds as fractions of the toxicity of the most toxic TCDD. Each compound is attributed a specific “Toxic Equivalency Factor” (TEF) .
Toxic equivalency factor (TEF) expresses the toxicity of dioxins, furans and PCBs in terms of the most toxic form of dioxin, 2,3,7,8-TCDD. [1] The toxicity of the individual congeners may vary by orders of magnitude .
The EPA’s Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk Assessments of 2,3,7,8- Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds (EPA. 2010) provides a formula (reproduced below) for calculating the exposure concentration for n DLCs in a mixture, in TCDD TEQ.
1 lut 2008 · The cumulative toxicity of the toxic congeners of polychlorinated biphenyls (PCBs), PCDDs, PCDFs, and PCDPEs in a sample is expressed through the 2,3,7,8-TCDD toxicity equivalent...
USEPA’s Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk Assessments of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dioxin-like Compounds (USEPA, 2009). Some health assessors may want to access additional resources for information on the advanced topics mentioned in this document.
2,3,7,8-tetrachlorodibenzodioxin (TCDD) is the most toxic of the family of 210 compounds. Seventeen of these PCDD/F compounds having chlorines in the 2,3,7, and 8 positions are designated for special concern because their shape makes them particularly bioactive.
