The Testing Programme for the Testing of Manufactured Nanomaterials tested 11 manufactured nanomaterials (MNMs) to generate information including their physico-chemical properties, environmental fate, and environmental and mammalian toxicity. The aims of the project were to (1) review which OECD Test Guidelines (hereafter TGs) and non-TG in vitro assays were applied in the OECD Testing Programme; (2) verify, where possible, to what extent these assays were applicable for MNMs testing; (3) recognise limitations of each assay when used for MNM testing; and (4) identify issues that might need to be further addressed (e.g. by proposing modifications to existing TGs). The present report summarises the information extracted from dossiers, presents the evaluation of the information extracted from the dossiers, and identifies potential next steps (e.g. where modification of existing TGs, or proposals of new TGs or Guidance Documents (GDs) could be appropriate). The recommendations and observations presented in this report are only based on the information extracted from the dossiers and recent publications on specific TGs