The science that students learn in school often revolves around solid and undisputed knowledge that has made it into textbooks. Nanoscience, on the other hand, appeals to students precisely because it is an evolving field, one in which there are many ongoing controversies. A new sci-ence course, jointly developed by the Department of Chemistry Education and the Department of Chemistry at the University of Hamburg, asks students to investigate a current socio-scientific issue involving nanoscience on their own. As part of the course, high school classes spend two days at the university, performing experiments, researching information and, finally, evaluating whether or not the silver nanoparticles designed to sanitize laundry are likely to have a negative environmen-tal impact. The article describes the scientific background of the technology employed, offers an overview of the laboratory-based course, and enumerates the competencies students are expected to gain after having worked on the topic for two days. Finally, we look at student reactions to the course.