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) Superphosphoric acid plant means any facility that concentrates wet-process phosphoric acid to 66 percent or greater P2O5 content by weight for eventual consumption as a fertilizer. A superphosphoric acid plant includes: evaporators, hot wells, acid sumps, oxidation reactors, and cooling tanks. An oxidation reactor includes any equipment or step that uses an oxidizing agent (e.g., nitric acid, ammonium nitrate, or potassium permanganate) to treat superphosphoric acid.

(b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods specified in §60.214, or equivalent or alternative methods.

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

[40 FR 33155, Aug. 6, 1975, as amended at 65 FR 61757, Oct. 17, 2000; 80 FR 50433, Aug. 19, 2015]