Tom Gebel is senior scientist and a scientific director at the German BAuA, the Federal Institute for Occupational Safety and Health in the division ‘Safety and Health with Chemical and Biological Agents’. He is toxicologist and responsible for nanotoxicology in BAuA. He is involved in the toxicological evaluation of workplace chemicals both with respect to hazard classification and occupational exposure limit setting. He chairs the Working Group fibres/particles of the German Committee on Hazardous Substances and is active in several other working groups of this committee . Tom Gebel is associate professor for environmental toxicology at the Technical University of Dortmund.