The European INDEX project was finalised to identify priorities and to assess the needs for an European Community strategy and action plan in the area of indoor air pollution. A list of 5 chemicals, with potential of high indoor concentrations, uncontested health impacts, and effective risk management, were selected to be regulated with priority: Formaldehyde, Carbon Monoxide, Nitrogen Dioxide, Benzene and Naphtalene. For each compound, guideline values and management options were suggested.