Summary Nanotechnologies are increasingly attracting attention in industrial as well as medical areas. The production of synthetic nanoparticles (SNP) continues to grow, despite the fact that the health and environmental impacts of these particles have not all been evaluated, and this has caused new problems. Also, the number of exposed workers continues to rise, in step with the expansion of the nanotechnology market. Although there is no global consensus in defining what is meant by an SNP, and no regulations clearly adapted to SNP, the need to protect workers is of major concern and requires appropriate risk management.Science has been exploring the numerous properties of SNP for 10 years, though many questions remain unanswered. These relate to the risk factors most likely to have adverse effects on human health, and the mechanisms leading to deterioration in human health and safety following exposure to SNP. Knowledge concerning its risks (exposure, toxicity, fire, explosion, etc.) is changing rapidly. This knowledge derives from the various methodological approaches employed, and encompasses nanoparticles obtained from a variety of sources (cellulose, fullerenes, metals and metal oxides, etc.). Consequently, comparing various results or studies may be problematical. In addition, there is currently no standardized measurement procedure for characterizing nanoparticles, though some research teams are working to achieve this goal.In addition, companies often market SNP before conducting the relevant toxicological studies, and this too is cause for concern. The situation highlights the importance of developing recommendations on risk management strategies in parallel with research and development on these particles. Many favour adaptive risk management strategies that evolve with the advancement of knowledge, and that include forms of communication that are transparent with regard to any remaining uncertainties. In our context, the ultimate aim of the project was to build a prototype for a decision-making support tool in the area of managing risks to the health and safety of workers exposed to SNP. However, before being able develop a risk-management tool adapted to SNP, it was necessary to conduct a comprehensive review of scientific articles published between 2001 and 2011. Thus, the report was structured in a way that would create a detailed list of the risks associated with SNP within an occupational health and safety (OHS) framework. These risks were then classified and ranked to illustrate the complexity of a system in which all aspects of the risk were interdependent.Further steps in the risk classification described in this report would therefore be needed to refine the prototype for the decision-making support tool. This tool would be designed for producers of SNP and practitioners of prevention in the workplace to assist them in introducing control measures to ensure the health and safety of workers exposed to SNP.