---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchC/part51/subpartZ"
level: "subpart"
label: "Subpart Z"
heading: "Provisions for Implementation of PM 2.5 National Ambient Air Quality Standards"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchC-part51-subpartZ"
sections_count: 17
---

# Subpart Z — Provisions for Implementation of PM 2.5 National Ambient Air Quality Standards

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter C — Air Programs › Part 51 — Requirements for Preparation, Adoption, and Submittal of Implementation Plans

## Sections

- [§51.1000. Definitions.](/cfr/40/51.1000.md)
- [§51.1001. Applicability of part 51.](/cfr/40/51.1001.md)
- [§51.1002. Classifications and reclassifications.](/cfr/40/51.1002.md)
- [§51.1003. Attainment plan due dates and submission requirements.](/cfr/40/51.1003.md)
- [§51.1004. Attainment dates.](/cfr/40/51.1004.md)
- [§51.1005. Attainment date extensions.](/cfr/40/51.1005.md)
- [§51.1006. Optional PM 2.5 precursor demonstrations](/cfr/40/51.1006.md)
- [§51.1007. Reserved](/cfr/40/51.1007.md)
- [§51.1008. Emissions inventory requirements.](/cfr/40/51.1008.md)
- [§51.1009. Moderate area attainment plan control strategy requirements.](/cfr/40/51.1009.md)
- [§51.1010. Serious area attainment plan control strategy requirements.](/cfr/40/51.1010.md)
- [§51.1011. Attainment demonstration and modeling requirements.](/cfr/40/51.1011.md)
- [§51.1012. Reasonable further progress (RFP) requirements.](/cfr/40/51.1012.md)
- [§51.1013. Quantitative milestone requirements.](/cfr/40/51.1013.md)
- [§51.1014. Contingency measure requirements.](/cfr/40/51.1014.md)
- [§51.1015. Clean data requirements.](/cfr/40/51.1015.md)
- [§51.1016. Continued applicability of the FIP and SIP requirements pertaining to interstate transport under CAA section 110(a)(2)(D)(i) and (ii) after revocation of the 1997 primary annual PM 2.5 NAAQS.](/cfr/40/51.1016.md)