According to a September 29, 2022, press release, the Japan Business Council in Europe (JBCE) has proposed a harmonization of the classification of multi-walled carbon nanotubes (MWCNT) “based on the latest knowledge on the effects of carbon nanotubes (CNTs) in organisms.” JBCE notes that this classification is consistent with the classification of the International Agency for Research on Cancer (IARC). JBCE states that “the morphologies, physicochemical properties, and effects on the human organism depend on the different methods for carbon nanotube production” and that “from a chemical management perspective, different types of CNTs should be evaluated depending on their characteristics instead of simply grouping them all together under the category ‘CNTs.’” JBCE proposes that:

  • MWCNTs similar to MWCNT-7 should be classified as suspected human carcinogens (Carc. 2) in the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) classification. According to JBCE, “[t]herefore, straight CNTs, that are neither particularly long nor particularly short, should be considered possibly carcinogenic, as they might have asbestos-like effects in humans even though this has not been scientifically proven yet”; and
  • MWCNTs other than MWCNT-7 should be classified as non-carcinogenic in the GHS classification.