SUBSTANCE FLOWS THROUGH THE ECONOMY AND ENVIRONMENT OF A REGION .1. SYSTEMS DEFINITION

In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method is presented. SFA aims at providi ng the relevant information for a country's overall management strateg y regarding single substances or coherent groups of substances. This a rticle is dedicated to the presentation of a three-step general framew ork for SEA-type studies, and elaborates on its first step the systems definition. Attention is given to the definition of the external and internal system boundaries, the categorization of the system's element s, aspects of materials choice, time, and space, and how these depend on the aim of the conducted study. Moreover, a broader discussion is s tarted on the need for standardization of materials flow studies in ge neral.