On April 23-24, 2018, the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) held a NanoDialog to discuss “Nano-In-Vivo,” a long-term research project intended to close existing data gaps concerning the safety of nanomaterials. BMU, the Federal Environment Agency (UBA), the Federal Institute for Occupational Safety and Health (BAuA), and BASF SE, with the participation of the Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM) and the Federal Institute for Risk Assessment (BfR), launched the joint project in 2013. Using rat organisms, the project is studying the potential long-term effects of nanomaterials on the lungs and other organs. In particular, the tests are examining the impacts that low exposure levels have over a long period of time to identify the chronic effects of nanomaterials in the low-dose range. During the NanoDialog, meeting participants discussed the early study results. According to BMU, the study results will feed into ongoing work at the Organization for Economic Cooperation and Development and discussion within the European Union on the risk assessment of nanomaterials. The study results are expected to be published at the end of 2018.