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Documents for Recommended Toxicity Equivalency Factors for Human Health Risk Assessments of Dioxin and Dioxin-Like Compounds

These documents describe EPA's updated approach for evaluating the human health risks from exposures to environmental media containing dioxin-like compounds (DLCs). Dioxin and DLCs are structurally and toxicologically related halogenated aromatic hydrocarbons. Traditionally, the Toxic Equivalency Factor (TEF) Methodology, a component mixture method, has been used to evaluate human health risks posed by these mixtures.

EPA recommends the use of the consensus TEF values for 2,3,7,8-tetrachlorodibenzo-p-dioxin and DLCs published in 2005 by the World Health Organization. The U.S. EPA recommends these TEFs be used for all effects mediated through aryl hydrocarbon receptor binding by the DLCs including cancer and non-cancer effects. Using information that summarizes the range of relative toxicities of the DLCs, the U.S. EPA suggests that conduct of a sensitivity analysis be considered to illustrate the impact the TEFs have on the predicted risk.

  • Recommended Toxicity Equivalency Factors (TEFs) for Human Health Risk Assessments of Dioxin and Dioxin-Like Compounds: External Review Draft (pdf) (240.37 KB, September 1, 2009)
  • Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk Assessments of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds (pdf) (636.42 KB, December 2010, 100-R-10-005)

Risk Assessment

  • About Risk Assessment
  • Human Health Risk Assessment
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    • Regional Screening Levels (RSLs)
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  • Superfund Risk Assessment
    • Superfund Human Health Risk Topics
      • Risk Assessment Guidance for Superfund (RAGS): Part A
      • Supplement to RAGS Part A: Community Involvement in Superfund Risk Assessments (1999)
      • Risk Assessment Guidance for Superfund (RAGS) Volume III: Part A
      • Risk Assessment Guidance for Superfund (RAGS): Part B
      • Risk Assessment Guidance for Superfund (RAGS) Part C
      • Risk Assessment Guidance for Superfund (RAGS): Part D
      • Risk Assessment Guidance for Superfund (RAGS): Part E
      • Risk Assessment Guidance for Superfund (RAGS): Part F
    • Superfund Ecological Risk Topics
      • Ecological Risk Assessment Guidance for Superfund
      • Ecological Soil Screening Level (Eco-SSL) Guidance and Documents
    • Additional Superfund Risk Topics
      • Regional Screening Levels (RSLs)
      • Regional Removal Management Levels for Chemicals (RMLs)
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Last updated on August 8, 2024
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