Engineered nanoparticles are materials purposefully produced with at least one dimension between 1 and 100 nanometers. Nanotechnology has the potential to dramatically improve the effectiveness of a number of existing consumer and industrial products and could have a substantial impact on the development of new products in all sectors. However, nanoparticles is little known about what effect these properties may have on human health. This materials provide an overview of what is known about the potential hazards of engineered nanoparticles and measures that can be taken to minimize workplace exposures.