The European Commission's Joint Research Centre is conducting a survey to collect information on expert experiences and opinions on methodologies for the risk assessment of chemical mixtures. This questionnaire is addressed to experts in authorities, academia, NGOs, consultancy and industry that are involved in the risk assessment (human or environmental) of chemical mixtures. However, the questionnaire is open and can therefore be filled in by anyone who has a general interest in the issue. To access the survey please use the following link: https://ec.europa.eu/eusurvey/runner/MixtureToxSurvey2015 To fill in the survey will take approximately 20 min. We would be grateful to receive your answers by 28 February 2015.