40 CFR § 63.11172 - When do I have to comply with this subpart?
---
identifier: "/us/cfr/t40/s63.11172"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 63.11172 - When do I have to comply with this subpart?"
title_number: 40
title_name: "Protection of Environment"
section_number: "63.11172"
section_name: "When do I have to comply with 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"
---
# 63.11172 When do I have to comply with this subpart?
The date by which you must comply with this subpart is called the compliance date. The compliance date for each type of affected source is specified in paragraphs (a) and (b) of this section.
(a) For a new or reconstructed affected source, the compliance date is the applicable date in paragraph (a)(1) or (2) of this section:
(1) If the initial startup of your new or reconstructed affected source is after September 17, 2007, the compliance date is January 9, 2008.
(2) If the initial startup of your new or reconstructed affected source occurs after January 9, 2008, the compliance date is the date of initial startup of your affected source.
(b) For an existing affected source, the compliance date is January 10, 2011.