The interim report covers the status quo on the use of scrubbers (Exhaust Gas Cleaning Systems, EGCS) for sulphur reduction in seagoing ships. Based on a literature study, it includes technical aspects, a market analysis, legal framework and the status of research activities. The focus is on discharge water. Prior research studies demonstrated an acidic pH and the presence of several pollutants such as heavy metals, polycyclic aromatic hydrocarbons, oil residues and nitrate in relevant concentrations. Ecotoxicological analyses demonstrated toxicity effects and that the single-pollutant approach alone is not sufficient for the environmental risk assessment of EGCS discharge water. Despite the current regulation, concerns regarding the impacts on the marine environment due to these emissions remain. Considering that, present and future studies should provide valuable input to the process of appropriate regulation.