The risk assessment of nano and microplastic particles is challenging, due to high uncertainties on release, exposure as well as hazard. The field is characterised by many data gaps, and is quite diverse in the sense that nano and microplastic encompass a huge variety in different polymer materials, size fractions, as well as properties that are tailored by the addition of various substances. To facilitate risk assessment, within the Horizon 2020 project PlasticsFatE two different approaches are developed with different scopes, namely decision trees to support Integrated Approaches to Testing and Assessment (IATAs) as well as a Prospective Multi Criteria Decision Support System (PMCDS).