The U.S.A and European nanosafety communities have a longstanding history of collaboration. On both sides there are working groups, NanoWG and WG-F (previously called WG4) of the NanoSafety Cluster. I have been chair of WG4 for about three years and still active in the group, though in the past half year, without dedicated funding, less active. That is already changing again with the imminent start of the NanoCommons project.