40 CFR § 63.9880 - What is the purpose of this subpart?

---
identifier: "/us/cfr/t40/s63.9880"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 63.9880 - What is the purpose of this subpart?"
title_number: 40
title_name: "Protection of Environment"
section_number: "63.9880"
section_name: "What is the purpose of this subpart?"
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "63"
part_name: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
regulatory_source: "57 FR 61992, Dec. 29, 1992, unless otherwise noted."
cfr_part: "63"
---


# 63.9880 What is the purpose of this subpart?

This subpart establishes national emission standards for hazardous air pollutants (NESHAP) for primary magnesium refineries. This subpart also establishes requirements to demonstrate initial and continuous compliance with all applicable emission limitations, work practice standards, and operation and maintenance requirements.