How can the sustainability of industrial symbioses be measured?

In the scientific literature, there are (so far) few studies quantifying the environmental benefits or sustainability of Industrial Symbiosis (IS) networks although, at the same time, the potential tools for these kinds of assessments have been developed rapidly both in number and capacity. In this article, we first review the existing studies on the environmental performance of IS systems. We draw a conclusion that these studies usually only concentrate on one or a limited number of factors and also use a narrow approach to system boundaries considering just the impacts taking place within the symbiosis. Finally, we suggest that The Natural Step (TNS) System Conditions could constitute a basis which - through a set of sustainability criteria and a series of questions derived from them - would essentially steer the analyses made about the environmental performance and overall sustainability of the IS network at hand.