This document presents a statement of the Best Available Techniques for chlorine production plants using the amalgam chlor-alkali electrolysis process, in relation to mercury emissions to air, to water and in products. It includes also information on the handling of solid wastes coming from normal operation (but not mercury containing construction waste or rubber coatings), and has been based on the practices of existing plants whose current performance provides the best examples of mercury emission control. However, it must be interpreted on the basis of several important principles contained within the IPPC Directive and the associated Reference Document.