The new EU regulation REACH requires the evaluation of the physico-chemical properties of a large number of substances in order to allow their use before 2018. Taking into account the number of substances and properties, the timing, the economic costs, the feasibility at the R&D level and the risks for the manipulator, in particular for the characterization of the dangerous physico-chemical properties (explosibility, flammability), the experimental measurement of all the data is not realistic. Thus, the development of alternative predictive methods for the evaluation of the properties of substances was recommended in the framework of REACH. In this context, the French PREDIMOL (molecular modeling prediction of physico-chemical properties of products) project [1] funded by ANR (National Research Agency) has started in November 2010 for 3 years. This project is conducted by INERIS associated with several public and private partners. Its objective is to demonstrate that molecular modeling is a credible alternative method to experimental characterization to predict in a reliable and fast manner, the whole range of physico-chemical properties of substances required by EU-REACH's regulation (annexes VII and IX) and for the industry in terms of property-screening method. In a first step, the project is focused on the prediction of physico-chemical properties related to organic peroxides, amines and halogenated compounds. In a second phase of the project, high throughout predictions will be considered. More precisely, predictive and validated QSPR (Quantitative Structure-Property Relationship) models related in particular to hazardous properties (like explosibility) are developed whereas molecular simulation methods (Molecular Dynamics, Monte Carlo) are used or adapted for thermo-physical properties like viscosity or density. Another critical objective of this project is the regulatory validation of models by European chemical instances in order that predictive data could be used for registration of chemicals in REACH. Hence, they will be submitted to the JRC comity for acceptance or to existing tools (like QSAR toolbox) for integration. In 2011, existing group contribution methods, QSPR models notably associated with quantum chemical description of molecular structures, SAFT equations, COSMO-RS approach and force fields that could be used for the prediction of the properties of the compounds under concerned have been identified, stressing onto performances and limits of each approach. Inventory of existing experimental data from literature has also been established. As predictivity of QSPR models highly depends on the database pertinence in terms of number of data, coherence and uncertainties of measurements, reliable experimental databases have been consolidated, in particular for the enthalpy of decomposition of organic peroxides.