This action promulgates national emission standards for hazardous air pollutants (NESHAP) for new and existing major sources in phosphoric acid manufacturing and phosphate fertilizers production plants (SIC 2874). Hazardous air pollutants (HAPs) emitted by the facilities covered by this rule include hydrogen fluoride (HF); arsenic, beryllium, cadmium, chromium, manganese, mercury, and nickel (HAP metals); and methyl isobutyl ketone (MIBK). Human exposure to the HAP constituents in these emissions may be associated with adverse carcinogenic, respiratory, nervous system, dermal, developmental, and/ or reproductive health effects. Implementation of the rules will achieve an emission reduction of HF estimated at 315 megagrams per year (Mg/yr) (345 tons per year [tpy]). The standards will reduce 940 Mg/yr (1035 tpy) of total fluorides and particulate matter containing heavy metals which are regulated pollutants under the Clean Air Act as amended (the Act). This action also amends 40 CFR part 9 by updating the table of currently approved information collection control numbers to include the information requirements contained in this final rule. The standards are promulgated under the authority of section 112 of the Clean Air Act (the Act) and are based on the Administrator's determination that phosphoric acid manufacturing and phosphate fertilizers production plants may reasonably be anticipated to emit several of the 188 HAPs listed in section 112(b) of the Act from the various process operations found within the industry. The NESHAP will provide protection to the public by requiring all phosphoric acid manufacturing and phosphate fertilizers plants that are major sources to meet emission standards reflecting the application of the maximum achievable control technology (MACT).