Over the last decade debate among environmental pressure groups, industry, and the authorities overthe threat posed by chlorine has become extremely polarized. In response, the Dutch minister of the environment commissioned a strategic study on chlorine. The first phase of the study described in this article, was designed as a substance flow analysis, encompassing some 99% of the flows of chlorinated hydrocarbons (CHC) in the Netherlands. The study provided an overview of flows of CHC through the Dutch anthroposphere and to inventory the leaks to the environment. Emissions, wastestreams, exports, imports, and flows through the anthroposphere were inventoried, drawing on all possible sources including the Dutch emission registration database, life‐cycle assessment (LCA) databases, and industrial data. Emissions were evaluated using the characterization step from LCA methodology. Emissions with toxicological effects were also evaluated on the basis of actual risk assessments of the National Institute of Public Health and Environmental Protection (RIVM).This resulted in the establishment of six groups of priority segments in the Dutch chlorine chain, for which additional measures will be prepared. The study showed that the environmental groups' pronouncements about the structural dangers associated with the chlorine chain are not supported by current knowledge. The study however; also indicates that important areas of uncertainty require attention, especially relating to the possible emissions of persistent bioaccumulating toxic micropollutants.