This document contains data on chlorobenzenes with regard to sources and distribution, the risks based on a consideration of exposure levels and harmful concentrations and the technical possibilities to reduce these risks. Chlorobenzenes form a group of 12 compounds in total. They are unnatural ; often they are produced by humans by chlorating benzenes, but it is possible that they are formed by integration of substreams of waste water and/or by degradation of chlorinated hydrocarbons. In the Netherlands there are standards and guidelines for soil and groundwater and for surface water, water and soil.<br>