EPA is withdrawing two significant new use rules (SNURs) promulgated under section 5(a)(2) of the Toxic Substances Control Act (TSCA) for substances which were the subject of premanufacture notices (PMNs), i.e., dodecandioic acid, 1, 12-dihydrazide (CAS No. 4080-98-2; PMNs P-01-759 and P-05-555) and thiophene, 2,5-dibromo-3-hexyl- (CAS No. 116971-11-0; PMN P-07-283). EPA published the SNURs using direct final rulemaking procedures. EPA received notices of intent to submit adverse comments on these rules. Therefore, the Agency is withdrawing these SNURs, as required under the expedited SNUR rulemaking process. EPA also intends to publish in the Federal Register, under separate notice and comment rulemaking procedures, proposed SNURs for these two substances.