Read-across is a valuable technique that Nanoconsult is currently exploring in advising ICCA on health impact assessment of microplastic particles. While learning the principles, the availavble literature and guidance documents from ECHA (RAAF, 2017) it appeared more and more to be network of rules and principles that have been made up behind a desk carefully separating practice and theory of legislation. Actually, when using a read-across done in real-life by ISO in setting its ISO 18562 standard fro wear particles,the target materials were not defined and the hypothesis not even mentioned in the standard text. Better is the current ToxRisk approach (Escher et al, 2019) in which the problem formulation, the context and the degree of uncertainty are driving factors for the exercise. Interested in read-across, check out the documents above or contact us. It is clear from our experience that this neonate needs some care before it can grow into adulthood.