Currently there are no testing and assessment strategies for environmental fate and effects taking the specific properties and behaviour of engineered nanomaterials into account. Therefore, the project objective was to develop a strategy for the investigation of ecotoxicity and environmental fate that allows the consideration of nano-specific effects within the environmental risk assessment of nanomaterials. For the development of the test strategy, both the results of "classic" assessment as well as those of recognized non-standardized endpoints were taken into account. For this analysis environmental fate and effects were addressed separately. Furthermore, the discussions of national and international level,  e.g. the conclusions of the expert meeting on Ecotoxicology and Environmental fate of the ⁠OECD⁠ Working Party on Manufactured Nanomaterials were taken into account. The test strategy considers various levels of test complexity as they are to be used in a tiered risk assessment scheme on the basis of a full life-cycle assessment. For the environmental risk assessment approach, the use of mathematical models and trigger values to either stop the procedure or proceed to the next tier is included. The presented test strategy features an overarching approach to test and assess fate and effects of NM while considering the specific challenges when investigating the potential environmental impact of NM.