40 CFR § 439.4 - General limitation or standard for pH.

---
identifier: "/us/cfr/t40/s439.4"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 439.4 - General limitation or standard for pH."
title_number: 40
title_name: "Protection of Environment"
section_number: "439.4"
section_name: "General limitation or standard for pH."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "N"
subchapter_name: "EFFLUENT GUIDELINES AND STANDARDS"
part_number: "439"
part_name: "PHARMACEUTICAL 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: "33 U.S.C. 1311, 1314, 1316, 1317, 1318, 1342 and 1361."
regulatory_source: "48 FR 49821, Oct. 27, 1983, unless otherwise noted."
cfr_part: "439"
---


# 439.4 General limitation or standard for pH.

The pH must remain within the range 6.0 to 9.0 in any discharge subject to BPT, BCT or NSPS limitations or standards in this part.

[68 FR 12271, Mar. 13, 2003]