Background The EU REACH Regulation promotes a new vision for handling chemical substances. It requires information from manufacturers and/or importers confirming that chemical substances have been evaluated as safe for the intended use. The use of non-animal alternative methods has been foreseen within REACH. In particular, the use of computational means to calculate properties of chemicals is explicitly mentioned by the Regulation, and the criteria are also defined for the so-called (quantitative) structure-activity relationship, (Q)SAR. Presently there is a lack of experience in Europe on the use of (Q)SAR models, although they have been used for decades in regulatory processes in the United States of America. By adopting (Q)SAR, chemical companies will not only be able to avoid producing unsafe chemicals, even before their synthesis, they will also save money and resources. Objectives The PROSIL project aims to facilitate a proactive attitude amongst chemical companies about the REACH Regulation. This will help to promote a transition towards a more responsible environmental approach, and lead to reductions in health risks. Project work will cover both existing and new chemicals, to enable the industry to take account of relevant toxicity properties right from the planning phase of chemical plants. The main objectives include: Establishing a network of REACH-related laboratories for the chemical industry; Exploiting in silico methods for assessing particular situations of chemical substances: chemical categories and mixtures of chemicals of natural origin; Integrating (Q)SAR models within mainstream industrial procedures; Screening new chemicals to ensure they are safe;Exploiting methods to generate structural alerts from confidential data; Producing case studies in the following industrial sectors: dyes, leather, and pesticides; andImproving standardisation on the use of non-testing methods. Expected results: Anticipated project outcomes include: A procedure to screen all compounds within a mixture of chemical compounds; Promotion of (Q)SAR tools, which are safe, residue-free, and environmentally benign compared to experimental methods; Creation of a guidance document and software for integrating the results from (Q)SAR and read across; A procedure for scrutinising the safety of candidate new chemicals, before their synthesis; A procedure for exploiting the hazard values of related compounds within a group of similar compounds; Development of a network of projects and initiatives applying (Q)SAR models for industry; Publication of success stories from the dyes, pesticides and leather sectors.