This action amends the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Petroleum Refineries in three respects. First, this action adjusts the compliance date for regulatory requirements that apply at maintenance vents during periods of startup, shutdown, maintenance or inspection for sources constructed or reconstructed on or before June 30, 2014. Second, this action amends the compliance dates for the regulatory requirements that apply during startup, shutdown, or hot standby for fluid catalytic cracking units (FCCU) and startup and shutdown for sulfur recovery units (SRU) constructed or reconstructed on or before June 30, 2014. Finally, this action finalizes technical corrections and clarifications to the NESHAP and the New Source Performance Standards (NSPS) for Petroleum Refineries. These amendments are being finalized in response to new information submitted after these regulatory requirements were promulgated as part of the residual risk and technology review (RTR) rulemaking, which was published on December 1, 2015. This action will have an insignificant effect on emissions reductions and costs.