On March 28, 2012, EPA proposed a significant new use rule (SNUR) under section 5(a)(2) of the Toxic Substances Control Act (TSCA) for 9 benzidine-based chemical substances (dyes), di-n-pentyl-pthalate (DnPP) and alkanes, C12-13, chloro (CASRN 71011-12-6). Under a SNUR, persons who intend to engage in any significant new use would be required to notify EPA at least 90 days before commencing that new use. The required notification would enable EPA to evaluate the significant new uses of these chemical substances and, if necessary, appropriately address risks to human health or the environment by limiting or prohibiting those uses before they occur. EPA proposed to add nine chemicals (dyes) to the benzidine-based chemical substances (dyes) Significant New Use Rule (SNUR) at 40 CFR section 721.1660. The amendment would make the exemption for persons that process or import these chemical substances as part of articles inapplicable for chemicals previously listed in 40 CFR section 721.1660(a)(2) as well as for the nine benzidine-based dyes identified in the proposed SNUR. EPA also proposed to designate any use of DnPP, except as a chemical standard for laboratory use, as a significant new use. In addition, EPA proposed to designate any use of alkanes, C12-13, chloro (CASRN 71011-12-6) a significant new use.