The US Environmental Protection Agency (EPA) proposed on December 28, 2011, significant new use rules (SNURs) for 17 chemical substances that were the subject of premanufacture notices (PMN), including seven substances with the term carbon nanotube (CNT) and seven substances with the term fullerene in their respective names. These 14 substances are subject to consent orders under Section 5(e) of the Toxic Substances Control Act (TSCA). This column provides background on, and the implications of, these proposed SNURs.
EPA has generously used its TSCA SNUR authority when reviewing PMN chemical substances that include nanoscale substances. Under TSCA Section 5, EPA can act cautiously and limit the opportunities for widespread release of new chemical substances — particularly where EPA determines the chemical or its use may present an unreasonable risk of injury to human health or the environment.
EPA states that the 14 nano substances at issue are subject to "risk-based" consent orders under TSCA Section 5(e)(1)(A)(ii)(I). Under this provision, the limitations that apply to the notice submitters are memorialized in a consent order negotiated between EPA and the PMN submitter. Consent orders require protective measures intended to limit exposures or otherwise mitigate potential unreasonable risk, and related provisions designed to minimize risk and elicit additional information about potential risks. A consent order's limitations only apply to the notice submitter. EPA often thereafter issues a SNUR for substances subject to Section 5(e) consent orders to apply the limitations to all subsequent substance manufacturers by way of regulation.
Three observations are worth noting about the proposed rule. 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., "carbon nanotube (CNT), multi-walled carbon nanotube (MWCNT), double-walled carbon nanotube (DWCNT), or single-walled carbon nanotube (SWCNT)." EPA uses the structural characteristics provided by the PMN submitter to characterize more specifically the TSCA Inventory listing for an individual CNT.
According to EPA, all submitters of new chemical notices for CNTs have claimed those specific structural characteristics as confidential business information. The proposed rule includes 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. EPA states it's using the specific structural characteristics for all CNTs submitted to help develop standard nomenclature for placing these substances on the TSCA Inventory.
EPA compiled a generic list of those structural characteristics entitled "Material Characterization of Carbon Nanotubes for Molecular Identity (MI) Determination & Nomenclature." A copy of the list is available under docket ID number EPA-HQ-OPPT-2010-0279.
Second, EPA designates a use as of the date of publication of a proposed SNUR, not the publication date of the final rule. EPA clarifies that persons who begin commercial manufacture, import or processing of the chemical substance that would be regulated would have to cease any such activity and resume them only after compliance with all applicable SNUR notice requirements and wait until the notice review period expires.
Third, EPA offers useful advice in the proposal to potential Significant New Use Notice (SNUN) submitters. A SNUN is simply a chemical with a significant new use designation. EPA notes that it's better able to evaluate a SNUN if detailed information is provided, including: human exposure and environmental release that may result from significant new use of the substance; potential benefits of the substance; and information on risks posed by the substance compared to risks posed by potential substitutes. The first suggested set of data is the most challenging, and certainly the most costly to assemble. Nonetheless, a SNUN that includes this information has a significantly better chance of a favorable review than applications lacking such data.
The proposal offers useful insights into EPA's approach to the regulation under TSCA of nanoscale chemical substances. While the comment opportunity was very limited, it will be interesting to see if the public and other interested stakeholders weighed in and if so, whether any final rule will be appreciably different.
LYNN BERGESON is Chemical Processing's Regulatory Editor. You can e-mail her at Lbergeson@putman.net.
Lynn is managing director of Bergeson & Campbell, P.C., a Washington, D.C.-based law firm that concentrates on chemical industry issues. The views expressed herein are solely those of the author.