The effects of synthetic nanoparticles on human health and the environment are still poorly understood and therefore uncertain. In particular, it is unclear in which areas nanoparticles-dose caused negative effects in the organism or in the environment (unknown dose-response relationship). The underlying toxicological mechanisms and possible effects of nanoparticle exposure over long periods of time are poorly understood. In product advertisements on the Internet and in reports in international journals, especially the functional properties of “nanotextiles” are described. The type of integration of the nanoparticles in textiles is often described only sparsely. Therefore, the present document is based primarily on research studies that include information on the integration of the nanoparticles in the textile material. The purpose of the present document is to give some guidance on tests to nanoparticle release. The determination of the release of nanoparticles could be performed either through quantification by chemical analysis (5.1), or by determining the linting (5.2), for example.