On February 25, 2013, the U.S. Environmental Protection Agency (EPA) published proposed significant new use rules (SNUR) under the Toxic Substances Control Act (TSCA) for 37 chemical substances that were the subject of premanufacture notices (PMN). EPA notes that the proposed SNURs include 14 PMN substances whose reported chemical names include the term “carbon nanotube” (CNT) or “carbon nanofibers.”  If issued in final, the SNURs would require persons who intend to manufacture, import, or process the chemical substances for an activity that is designated as a significant new use to notify EPA at least 90 days before commencing that activity. EPA states that the required notification would provide it with the opportunity to evaluate the intended use and, if necessary, to prohibit or limit that activity before it occurs. Comments are due April 26, 2013.

EPA states that, because of a lack of established nomenclature for CNTs, the TSCA Inventory names for CNTs are currently in generic form, e.g., CNT, multi-walled carbon nanotube (MWCNT), double-walled carbon nanotube (DWCNT), or single-walled carbon nanotube (SWCNT). According to the notice, EPA uses the specific structural characteristics provided by the PMN submitter to characterize more specifically the TSCA Inventory listing for an individual CNT. All submitters of new chemical notices for CNTs have claimed those specific structural characteristics as confidential business information (CBI). EPA states that it is publishing the generic chemical name along with the PMN number to identify that a distinct chemical substance was the subject of the PMN without revealing the confidential chemical identity of the PMN substance.

Because confidentiality claims preclude a more detailed description of the identity of these CNTs, EPA asks that an intended manufacturer, importer, or processor of CNTs that is unsure whether its CNTs are subject to the proposed SNUR contact EPA or obtain a written determination from EPA pursuant to the bona fide procedures at 40 C.F.R. Section 721.11. EPA states that it is using the specific structural characteristics for all CNTs submitted as new chemical substances under TSCA to help develop standard nomenclature for placing these chemical substances on the TSCA Inventory.

Importantly, EPA has compiled a generic list of those structural characteristics entitled “Material Characterization of Carbon Nanotubes for Molecular Identity (MI) Determination & Nomenclature.” If EPA develops a more specific generic chemical name for these materials, that name will be made publicly available.