The emission of vehicle brakes has become an important topic in the last few years. Before there was no negative aspect since asbestos was forbidden in brake pads and there was no discussion concerning the impact of nanoparticles in general. The current discussion started with complaints about brake dust staining of the wheel. Since then, several attempts were made to understand the synthesis, composition and distribution of brake dust because of the growing awareness of environmental and health effects, for example with antimony and copper in the brake pads. Beside the combustion engine, the brake is the main emitter of nano-sized particles on a passenger car.[1-3] The environmental problem of brake dust was reviewed in previous scientific work, e.g. "Method for visualization and handling of brake dust emissions" by Audi AG and TU Ilmenau, chassis.tech 2010. There are a few materials in brake pads or their reaction products which led to discussions, e.g. the content of copper or antimony.

Prof. Dr.-Ing. Klaus Augsburg, Hannes Sachse*, Dr. Stefan Krischok, Rüdiger Horn - Technical University Ilmenau Prof. Dr. Marcus Rieker, Daniel Scheder - HORIBA Europe