On April 4, 2012, the U.S. Environmental Protection Agency (EPA) promulgated, through a direct final rule, significant new use rules (SNUR) for 17 chemical substances that were the subject of premanufacture notices (PMN). This includes a SNUR for “infused carbon nanostructures (generic).” According to EPA, the PMN states that the generic (non-confidential) use of the substance is as an additive to provide conductive properties to reinforcements used in composites. EPA states that, based on available information on analogous chemical substances, the PMN substance may cause lung effects. For the use described in the PMN, however, no significant inhalation exposures are expected, and EPA “has not determined that the proposed manufacturing, processing, or use of the substance may present an unreasonable risk.” EPA notes that it has determined, however, that a manufacturing process other than as described in the PMN may cause serious health effects. Based on this information, EPA states the PMN substance meets the concern criteria at 40 C.F.R. Section 721.170(b)(3)(ii). EPA determined that the results of the following information would help characterize the health effects of the PMN substance: the dimensions, characteristics, and physical-chemical properties of the carbon nanostructures. Under the SNUR, these properties should be determined once a year for three consecutive years. The direct final rule is effective on June 4, 2012. Written adverse or critical comments, or notice of intent to submit adverse or critical comments, are due May 4, 2012.