The PolySafe proposal is entitled “Safe operation of an intensified continuous heat-exchanger reactor for polyphasic reactions”. The partners of the project are: 1. LGC (Laboratoire de Génie Chimique): research laboratory recognized in the field of Process Engineering, which includes a strong activity in the fields of intensified reactors and process safety. 2. INERIS (Institut National de l'Environnement industriel et des RISques): a public institute of an industrial and commercial character, under the supervision of the French Ministry of the environment. It has a recognised role in the assessment and prevention of technological and environmental risks for both environmental and human protection. 3. CEA (Commissariat à l’Energie Atomique) / LITEN (Laboratoire d’Innovation des Technologies pour les Energies nouvelles et les Nanomatériaux): its mission is to develop new technologies for energy (fuel cell, hydrogen production, biomass, solar technologies). Two departments are involved in this project: the DTBH/LCTA (for materials and process aspects) and the DTS/LETh (for heat-exchanger reactor design and functional tests aspects). SDMS Technologies, a leader company in the field of high technology equipments manufacturing, has expressed a full support to the PolySafe project and proposes to include the manufacture of PolySafe heat-exchangers/reactors in their industrial offer. 4. BSF (BlueStar Silicones France): one of the world industrial leaders in the field of the silicone technology. The main production sites of the company are in France. Its research and development centre (about one hundred scientists), is located on the industrial site of Saint-Fons. The general objective of the project is to demonstrate the inherently safer characteristics and versatility of an innovative intensified continuous heat-exchanger/reactor (HEX). The studied class of reactions proposed by BlueStar Silicones France, involving polyphasic mixtures, arises from the domain of the chemistry of silicones. More precisely, it concerns the hydrolysis of chlorosilanes which is a step for the production of silicone polymers. At present, these reactions are carried out in a batch reactor or in a loop reactor with an external heat-exchanger to evacuate the heat generated. The goal is to operate in an intensified process in order to complete the reaction and to eliminate the exothermic solubilisation step of hydrochloric acid produced. The expected advances are safety improvement (control of thermal risk, suppression of corrosion likely to produce chlorine leaks), environmental impact reduction (less by-products, no treatment step of solvents) and economical gain (chlorine recovery). Moreover, an aim of the project is to design and build a heat-exchanger/reactor by diffusion welding process using Hot Isostatic Pressing (HIP). This technique, well acquired by the CEA, has proven its technological and economical merits for chemical heat-exchanger/reactors involved in previous projects and allows a straight forward scale-up of the HEX to the industrial scale. According to the general goal of the proposal, the main focuses concern process risk analysis, modelling and simulating in failure modes, pressure holding of devices and application to polyphasic reactions (L/L and L/L/G), what will underline the HEX versatility. The emphasis is with respect to less pollution, less expendable material and energy for innovative chemistry as well as new process design able to operate a sustainable chemistry.