Last week I attended through webcast the 2-day workshop on Microplastics organized by the National Academy of Sciences in the USA in Washington DC. I was struck by the enormous drive of research groups to identify and characterise these solid materials in seas, soils and tissues. At the same time it reminded me to the first discussion and meetings on nanoparticles about 20 years ago. At that time nanoparticles were developed for specific purposes and hard to assess by the numerous variations, sizes and materials. Bringing simple rules to the field will strengthen, focus an prioritize new reseach to assess potential health impact. Great to see, witness and hopefully influence the connection between these fields to define further steps and action. In nanotech the current slogan is Safe-by-Design, and this may well be an example for upcycling of polymers and plastics for circular use of components.