ChemSec's work to include nanomaterials on the SIN List started by preforming a pre-study, outlining the current situation for nanoforms under REACH, including current and previous discussions. The study looked into different approaches for the identification of nanomaterials as SVHCs, and outlined current evidence for hazardous properties for a number of common nanoforms.

This pre-study, as well as the full evaluation, was performed by Assistant Professor Steffen Foss Hansen and Professor Anders Baun from the Danish Technical University.

After discussions internally and with different experts, it was decided that carbon nanotubes were the most “promising” SVHC candidate, as the hazardous properties were well documented and in line with the SVHC criteria.

An in-depth study of the hazardous properties of carbon nanotubes was then conducted, outlining especially evidence of persistence as well as carcinogenic and reprotoxic properties. Independent academic studies as well as reports from agencies and research bodies (including IARC) were scrutinised.

It was discussed whether all forms of carbon nanotubes should be included and this was concluded to be the best approach considering:

  • Manufacture of carbon nanotubes results in products of varying purity. Thus in practice, a mixture of forms is present in processes and products that uses carbon nanotubes.
  • There is no evidence that some specific forms of carbon nanotubes would not share the hazardous properties of the others, rather this is unlikely.
  • Exempting some forms of carbon nanotubes might lead to the case of “regrettable substitution”: increased use of less studied (but probably not less hazardous) forms. This would be a costly effect that would not provide any true benefits to human health and the environment.