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May 22, 2013

EPA Promulgates SNUR for Functionalized Multi-Walled Carbon Nanotubes

Lynn L. Bergeson

On May 9, 2013, the U.S. Environmental Protection Agency (EPA) promulgated a significant new use rule (SNUR) for premanufacture notice (PMN) substance P-12-44, which is identified as “functionalized multi-walled carbon nanotubes.” According to the Federal Register notice, “[t]he PMN states that the generic (non-confidential) use of the substance is as an additive for rubber and batteries.” EPA states that it determined that “use of the substance other than as described in the PMN; manufacturing, processing, or use in a powder form; or any use of the substance resulting in surface water releases may cause serious health effects or significant adverse environmental effects.” EPA believes the results of the following tests would help characterize the health and environmental effects of the PMN substance: (1) A 90-day inhalation toxicity test (OPPTS Test Guideline 870.3465) with a post-exposure observation period of up to three months, bronchoalveolar lavage fluid analysis, particle size distribution information and other toxicologically relevant properties, data on histopathology of pulmonary and ex-pulmonary organs/tissues (cardiovascular, central nervous system, liver, kidney, etc.), pulmonary deposition (lung burden), clearance half-life (biopersistence) and translocation of the test material, and a determination of cardiovascular toxicity; (2) analysis by Scanning Transmission Electron Microscopy, Transmission Electron Microscopy, or Scanning Electron Microscopy of number of walls (range and average), tube ends (open, capped, circular, other), tube width/diameter (measure inner and outer diameters or range), tube length (range) including a description of any deformities found in the tubes (bumps, branching, gaps, etc.); (3) percent (range) of functional groups found on the tubes (include the method of determination); and (4) particle size determined by count not by weight or volume (preferably using Scanning Transmission Electron Microscopy). The rule is effective on July 8, 2013.