As used in this subpart, all terms not defined herein shall have the meaning given them in the Act and in subpart A of this part.

(a) Wet-process phosphoric acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. A wet-process phosphoric acid plant includes: Reactors, filters, evaporators, and hot wells.

(b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods specified in § 60.204, or equivalent or alternative methods.

(c) Equivalent P2O5 feed means the quantity of phosphorus, expressed as phosphorus pentoxide, fed to the process.