Background Degreasing is one of several steps in the hide tanning process. The amount of natural fat contained in sheepskins is significant and can have an effect on the process. Therefore, the fat has to be removed to avoid stains and dyeing irregularities. However, sheepskin degreasing results in a high degree of pollution in the tannery wastewater and, although there have been improvements in hide tanning technology, the ethoxylated nonylphenols (NPEs) used for degreasing are environmentally questionable. The replacement of NPEs by alyphatic ethoxylated alcohols could provide a solution to the problem. But this method is not used because it is less effective, yet more costly. Moreover, its inefficacy means that larger amounts of alyphatic ethoxylated alcohols have to be used, resulting in increasing to an even greater degree the Chemical Oxygen Demand (COD) added to the wastewater. Nevertheless, an efficient alternative has to be found given that NPEs are on the List of Priority Substances, the use of which, according to the Water Framework Directive of the European Community (Directive 2000/60/EC), has to be reduced. Objectives The main objective of the project is to come up with a suitable alternative to NPEs for sheepskin degreasing that is effective and has low wastewater pollution parameters. The project also examines the capacity of this alternative substance to be recovered for recycling, as well as the possibilities of reusing the fat in other ways. Finally, the project seeks to improve and optimise the sheepskin degreasing process as a whole, taking into consideration the quality of the final product - the leather produced. Results The beneficiary has proved that there is a ‘surfactant’ (surface active agent) able to substitute the current polluting chemicals used in the degreasing process of tanneries: i.e alyphatic ethoxylated alcohol can replace the ethoxylated nonylphenol, providing a tool for the leather sector in order to fulfil the requirements of the EU Water Framework Directive concerning the List of Priority Substances. Additionally, the new surfactant can be recovered for recycling and the separated fat is available for valorization as an industrial by-product. The environmental balance shows that the new process is also “environmentally” successful. Two main aspects to be taking into account are COD parameter contamination reduction and energy savings. Finally, the project has developed a tool to help to improve the European competitiveness on the basis of reuse of the recovered surfactant plus the possibility of a by-products revalorization.