English Abstract In this report a method is proposed for the derivation
of standards for the concentrations of organic contaminants in organic
fertilizers which are used on agricultural land. The method is based on the
premises that the long-term accumulation level of contaminants in soil, may
not cause a risk for the terrestrial ecosystem. Therefore, the estimated
long-term accumulation level in soil of these compounds, determined by the
annual addition and the half-life in soil, may not exceed the target values.
As a first application of the above described method, standards for the
concentrations of a number of organic micro contaminants in sewage sludge
and compost are proposed. Besides that also standards for contaminants in
very clean-compost and black soil are proposed. Because by the Dutch law
very clean compost and black soil are considered as soils, which as any
other soil have to meet the requirements of the target values in soil, the
standards for very clean compost and black soil are considerably lower than
those for sewage sludge and compost. The organic contaminants were selected
because of their persistent character in soil.