Toxicity Equivalency Factors (TEF)

Toxicity Equivalency Factors (TEFs) are numerical values used to compare the toxicity of various similar chemicals, such as dioxins and dioxin-like compounds. Since these chemicals differ in potency, TEFs help estimate their relative harmfulness by providing a standardized way to sum their combined effects. For example, a chemical with a TEF of 0.1 is considered one-tenth as toxic as the most harmful reference compound. This allows scientists to assess overall risk from complex mixtures of related chemicals by calculating a total toxic equivalent, aiding in health risk assessments and safety evaluations.