Summary Industrial nanotechnologies are developing at an exponential pace, and given the anticipated spinoffs, the economic potential across the globe is tremendous. Understandably, many countries are investing heavily in these new technologies, but we know little about their occupational health and safety risks, and experts in health risk assessment have a very different understanding of the safety programs that should guide their use than do the industries that use or manufacture nanomaterials. A number of studies show that the biological reactivity of nanoparticles, because of their very small size, differs from that of their counterparts of the same chemical composition but larger size. The main purpose of this project was to design a nanomaterial exposure assessment grid to promote safe handling of these materials. This project relied on cooperation between industry and health risk assessment experts to develop an integrated methodology and approach to nanosafety. The project included a literature review and development of a decision grid in cooperation with Québec and European companies that use or manufacture nanomaterials. The literature review indicated that the most appropriate methodology for this study was the health risk assessment model developed by the U.S. National Research Council (NRC) in 1983 to assess the risks of exposure to chemicals. A decision grid applicable to nanotechnologies was developed based on the four steps suggested by the NRC. The grid was validated by industrialists using nanotechnologies and presented at two international conferences for peer review. Minor changes were made to the grid based on the peer review. Nonetheless, the grid was favorably received, and the need to develop a risk assessment tool using our approach was acknowledged. This work is the first step towards a consensus approach satisfactory to both the health risk assessor (as it is based on the principles developed in 1983 by the NRC) and industries that produce nanoparticles. A second step is required to select chemical and biological characterization tests that will make it possible to standardize the decision grid. However, this work has nonetheless made it possible to develop an assessment tool that enables priority integration of chemical characteristics (such as nanoparticle reactivity and nanoparticle interaction with biological material) so that usage limits can be established for the type of nanoparticle assessed. In addition, this approach will help to increase public confidence because of the transparency demonstrated by the team in coming up with a development plan. Last, the originality of this innovative work stems largely from the researchers’ desire to take the first steps towards certification of products derived from engineered nanomaterials in partnership with occupational hygienists.