Nutrient and pollutant content of compost

The quantity of compost produced in Switzerland has been assessed, and the quality of individual composts has been determined and compared to the legal standards describing a minimal quality of compost. A last comparable study has been made in 1988. Today, more than 450’000 tons of fresh material are composted in more than 200 compost producing plants. One third of these plants did not analyse the quality of their compost until now. The remaining plants usually fulfill the requirements of limit values for heavy metals in compost without problems. There is an important lack in self-control of the hygienic quality of the compost. Hardly one quarter of plants fulfill this requirement. The content of litter contaminants in compost does not seem a big problem in most of the composting plants.