Skip to content
LexBuild

40 CFR § 422.50 - Applicability; description of the defluorinated phosphoric acid subcategory.

---
identifier: "/us/cfr/t40/s422.50"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 422.50 - Applicability; description of the defluorinated phosphoric acid subcategory."
title_number: 40
title_name: "Protection of Environment"
section_number: "422.50"
section_name: "Applicability; description of the defluorinated phosphoric acid subcategory."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "N"
subchapter_name: "EFFLUENT GUIDELINES AND STANDARDS"
part_number: "422"
part_name: "PHOSPHATE MANUFACTURING POINT SOURCE CATEGORY"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Secs. 301, 304 (b) and (c), 306 (b) and (c), and 307(c) of the Federal Water Pollution Control Act, as amended; 33 U.S.C. 1251, 1311, 1314 (b) and (c), 1316 (b) and (c), 1317(c); 86 Stat. 816  Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217."
regulatory_source: "39 FR 6582, Feb. 20, 1974, unless otherwise noted."
cfr_part: "422"
---

# 422.50 Applicability; description of the defluorinated phosphoric acid subcategory.

The provisions of this subpart are applicable to discharges resulting from the defluorination of phosphoric acid. Wet process phosphoric acid is dehydrated by application of heat and other processing acids such as vacuum and air stripping. The acid is concentrated up to 70-73% P<sub>2</sub> O<sub>5</sub> in the defluorination process.