In the stack emissions from a hazardous waste incinerator we found highly significant correlations between 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalents (I-TE) and pentachlorobenzene (Cl5Bz) and between I-TE and heptachlorobiphenyl (Cl7B). We therefore propose to utilize these substances as indicator parameters from which I-TE values can be estimated. Since they are easier to analyze than PCDD/F the use of indicator parameters such as Cl5Bz and Cl7B offers the chance to monitor I-TE emissions which are limited to 0.1 ng/m3 in many European countries.