The present report represents the deliverable 6.6 – “Report on scientific and technical advice on MCNMs/HARNs characterisation, exposure and hazard assessment to advance nanosafety assessment framework” and aim to present the lessons learnt in the WPs dealing with the characterisation of the Multicomponent Nanomaterials (MCNMs) and High Aspect Ratio Nanomaterials (HARNs) used in the industrial test cases and the observations obtained on-site during the monitoring campaigns carried out in the different demonstrators’ premises. Furthermore, this report describes also some difficulties experienced when performing exposure and hazard assessment experiments, while solutions are proposed in the form of recommendations for the possible adaptation of relevant SOPs/TGs to the characteristics of MCNMs and HARNs.