scope:

Introduction

This guideline addresses all congeners of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs and PCDFs), for which toxic equivalency factors (TEF) [1] according to WHO were derived. Maximum intake values (MIvalues) for livestock serve to protect animals so that safe food products can be obtained from them. Health, wellness and performance of these animals are not of primary concern which focuses instead on the deposition of PCDDs and PCDFs in edible tissue, primarily in fatty tissue and on the elimination with milk fat. Maximum intake values (MIvalues) are derived from experiments whose results provide information on the relationship between the concentrations in fodder and the resulting concentrations in the fat of the animals (so-called carry-over). Only those kinds of live-stock were considered for which this information was available. Because of the high expenditures of such experiments, only few usable data were available from experiments with dairy cows. A dose dependence of the effect, in this case the accumulation in the body and milk fat in dependence of the amount in fodder the dairy cows received, was not found because only one concentration was supplied with the fodder [10].

In spite of this shortcoming, a maximum intake value (MI-value) will be derived for dairy cows which is the sum of all measured PCDDs and PCDFs. According to present knowledge the derived value will in the long run not lead to such an accumulation of PCDDs and PCDFs in the edible tissue of these animals which would be cause to fear negative health effects in humans after consumption of this food due to concentrations in excess of the tolerated limits.

Combined effects with other organic chlorinated aromatic compounds were not included. The MIvalue applies to dairy cows which are kept and fed according to common practice.