Substance flow analysis is an analytical tool in the scientific field of industrial ecology, a possible operationalisation of the concept of industrial metabolism. 1 In this concept, an analogy is drawn between the economy and environment on a material level: the economy's “metabolism”, in terms of materials mobilisation, use and excretion to create “technomass”, is compared to the use of materials in the biosphere to create biomass. The economy is viewed only in terms of its material flow. The policy area most closely related to this concept is integrated chain management. Economic chains from cradle to grave are the subjects of regulation. This paper presents the implementation of substance flow analysis in the Flemish region of Belgium. In Belgium, there exists up to now relatively little or no experience with the use of substance flow analysis. In this context, the Flemish Government, more specific the competent Flemish minister for the Science and technological innovation policy supported a project regarding substance flow analysis on heavy metals.