Koen Verbist has a background in occupational and environmental hygiene. Over the past 10 years he has been working as occupational hygienist. First for Arbo Unie, an occupational health and safety organisation. And now since 4 years for Cosanta, who are the owner and developer of Stoffenmanager(r), an exposure and risk assessment tool. His main area of expertise are exposure assessment of hazardous substances , exposure modelling and giving various courses on exposure modelling. He is a member of the Dutch Occupational Hygiene Association, that funded this project.