Grouping all carbon nanotubes into a single substance category is scientifically unjustified

The International Chemical Secretariat (ChemSec) recently added carbon nanotubes (CNTs) to the so-called SIN (‘Substitute It Now’) list of chemicals that they believe should be restricted or banned in the EU1. CNTs are the first nanomaterials to be placed on the SIN list. Should this ‘designation’ concern us as scientists active in the areas of nanotoxicology and nanomedicine? Yes, as it implies that all CNTs can be considered as one material category, which is not the case.