US and Canadian regulators seeking to harmonise their legislative approaches for nanomaterials have created a classification scheme for the materials. Developed as part of the Regulatory Cooperation Council’s (RCC) Nanotechnology Initiative and presented at their 14 January 2014 webinar, it is said to be ‘the first time regulatory programs are considering a classification scheme […] to increase the utilization of read-across and analogue data’. It is expected to help the Canadian Environmental Protection Act (CEPA) and the US Toxic Substances Control Act (TSCA) ‘better utilize information from similar nanomaterials and provide increased transparency, consistency and alignment’ between the two.
The proposed classification scheme is ‘based on similarities in chemical composition’ and includes the following categories:
- Carbon nanotubes
- Inorganic carbon
- Metal oxides and metalloid oxides
- Metals, metal salts and metalloids
- Semi-conductor quantum dots
- Other (e.g. metal alloys, nanoclays, tubes of metals/metalloids, and bionanomaterials
The scheme is detailed in draft documents from three of the work programs under the initiative. These were shown to attendees of the RCC's 2014 January webinar:
- Work Element 2 focuses on Priority-setting, and deals with identifying ‘common criteria for determining characteristics of nanomaterials of concern/no-concern’, and has thusly developed the above-mentioned list. It states that the classificiation scheme should be ‘used only for sorting which nanomaterials need additional nano-specific consideration and which can be considered as traditional chemicals; while exceptions will continue to be considered on a case-by-case basis’.
- Work Element 3 is on Risk Assessment/Management, and this Appendix to it details the Nanoparticle Screening Assessment Framework; it states that ‘based on the analysis and discussions that occurred during the case study/comparative analysis exercises, a common approach for assessing and identifying additional testing requirements for nanoparticles was developed […]. [It] represents an effort to systematically focus human health concerns and additional testing requirements for nanoparticles based on physical characteristics’.
- Work Element 4, on Commercial Information, aimed to ‘characterize existing commercial activities and identify gaps and priorities for future knowledge gathering for nanomaterials’. In this capacity it has developed a Nanomaterials Use Matrix to help guide future activities.