40 CFR § 420.90 - Applicability; description of the acid pickling subcategory.

---
identifier: "/us/cfr/t40/s420.90"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 420.90 - Applicability; description of the acid pickling subcategory."
title_number: 40
title_name: "Protection of Environment"
section_number: "420.90"
section_name: "Applicability; description of the acid pickling subcategory."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "N"
subchapter_name: "EFFLUENT GUIDELINES AND STANDARDS"
part_number: "420"
part_name: "IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "33 U.S.C. 1311, 1314, 1316, 1317, 1318, 1342, and 1361."
regulatory_source: "47 FR 23284, May 27, 1982, unless otherwise noted."
cfr_part: "420"
---


# 420.90 Applicability; description of the acid pickling subcategory.

The provisions of this subpart are applicable to discharges and to the introduction of pollutants into publicly owned treatment works resulting from sulfuric acid, hydrochloric acid, or combination acid pickling operations.