Web-based Control Banding Tool using an Exposure Process Model. To assess health risks qualitatively after exposure to synthetic NPs. It concerns single particles as well as agglomerates or aggregates and applies to NPs that meet all of the following criteria: i) particles are not (water) soluble; ii) particles are synthetically produced and not released as unintentional by-product of e.g. incomplete combustion processes; iii) the size of the primary particles is smaller than 100 nm and/or the specific surface area of the nanopowder is larger than 60 m2/g