Nanomaterials--a wide variety of materials with a diameter of less than 100 nm--have unique properties. Nanotechnology is being promoted as the technology that will drive the next industrial revolution. Nanomaterials may have unique biological activities, but little research has been undertaken to investigate their potential effects on human health and the environment. Many seminal reports have identified gaps in our knowledge, and a large multidisciplinary effort will be required to undertake the necessary research to assist the framing of regulatory models to deal with any novel risks.