This action promulgates national emission standards for hazardous air pollutants (NESHAP) for miscellaneous organic chemical manufacturing facilities. The final rule establishes emission limits and work practice standards for new and existing miscellaneous organic chemical manufacturing process units, wastewater treatment and conveyance systems, transfer operations, and associated ancillary equipment and implements section 112(d) of the Clean Air Act (CAA) by requiring all major sources to meet hazardous air pollutants (HAP) emission standards reflecting application of the maximum achievable control technology (MACT). The HAP emitted from miscellaneous organic chemical manufacturing facilities include toluene, methanol, xylene, hydrogen chloride, and methylene chloride. Exposure to these substances has been demonstrated to cause adverse health effects such as irritation of the lung, eye, and mucous membranes, effects on the central nervous system, and cancer. We do not have the type of current detailed data on each of the facilities and the people living around the facilities covered by the final rule for this source category that would be necessary to conduct an analysis to determine the actual population exposures to the HAP emitted from these facilities and the potential for resultant health effects. Therefore, we do not know the extent to which the adverse health effects described above occur in the populations surrounding these facilities. However, to the extent the adverse effects do occur, and the final rule reduces emissions, subsequent exposures will be reduced. The final rule will reduce HAP emissions by 16,800 tons per year for existing facilities that manufacture miscellaneous organic chemicals.