This action promulgates national emission standards for hazardous air pollutants (NESHAP) for new and existing primary lead smelters pursuant to section 112 of the Clean Air Act (Act) as amended in November 1990. Primary lead smelters have been identified by the EPA as significant emitters of lead compounds, and other metal hazardous air pollutants (HAP) including arsenic, antimony, and cadmium. Exposure to lead compounds may result in adverse effects on the blood, central nervous system and kidneys. Chronic exposure to arsenic is associated with skin, bladder, liver and lung cancer and other developmental and reproductive effects. This NESHAP provides protection to the public by requiring all primary lead smelters to meet emission standards that reflect the application of maximum achievable control technology (MACT).