Readers engaged in nanomaterial applications may be interested in EPA’s new Significant New Use Rule (SNUR) for multi-walled carbon nanotubes (MWCNTs). Enterprises wishing to manufacture, import, or process MWCNTS are now potentially subject to Significant New Use Notice (SNUN) regulatory procedures which include the submission of ‘appropriate’ health and safety data. This rule is incorporated into the Code of Federal Regulations at 40 CFR § 721.10183.
EPA evaluation of MWCNTs, and carbon nanotubes generally, has established that exposure may cause lung effects (pulmonary toxicity, fibrosis, carcinogenicity), immunotoxicity, and mutagenicity. More information on toxicological effects is reported in the Summary of EPA’s Current Assessments of Health and Environmental Effects of Carbon Nanotubes (available in the MWCNT SNUR Docket).
EPA recommends SNUNs provide detailed information on the following:
- Human exposure and environmental release that may result from the significant new use of the chemical substance.
- Potential benefits of the chemical substance.
- Information on risks posed by the chemical substance compared to risks posed by potential substitutes.
EPA notes that upon review of a SNUN, the Agency has the authority to require additional testing. Any manufacturers, importers, or processors who intend to conduct testing or submit a SNUN are encouraged to contact EPA to determine ‘appropriate’ testing methods. Substantial detail about this and other governing TSCA provisions is provided in the FR notice (76 FR 26186 (available in the MWCNT SNUR Docket)). More information on SNUN requirements generally is available here and information on requirements for test data is available from EPA and the ACC.
This SNUR is specific to MWCNTs of a specific structure. However, confidentiality claims preclude a more detailed description of the identity of this MWCNT. To determine whether a specific CNT, MWCNT, or single-wall carbon nanotube is on the TSCA Inventory, manufacturers should submit a bona fide intent to manufacture or import to EPA.
Exempt from the rule are MWCNTs that are completely reacted (cured), incorporated or embedded into a polymer matrix that itself has been reacted (cured), or embedded in a permanent solid polymer form that is not intended to undergo further processing except for mechanical processing.