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 which concentrates wet-process phosphoric acid to 66 percent or greater P2O5 content by weight for eventual consumption as a fertilizer.

(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 P 2 O 5 feed means the quantity of phosphorus, expressed as phosphorus pentoxide, fed to the process.