---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchC/part52/subpartMM"
level: "subpart"
label: "Subpart MM"
heading: "Oregon"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchC-part52-subpartMM"
sections_count: 9
---

# Subpart MM — Oregon

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter C — Air Programs › Part 52 — Approval and Promulgation of Implementation Plans

## Sections

- [§52.1970. Identification of plan.](/cfr/40/52.1970.md)
- [§52.1971. Classification of regions.](/cfr/40/52.1971.md)
- [§52.1972. Approval status.](/cfr/40/52.1972.md)
- [§52.1973. Reserved](/cfr/40/52.1973.md)
- [§52.1974. Original identification of plan section.](/cfr/40/52.1974.md)
- [§52.1975-52.1986. Reserved](/cfr/40/52.1975-52.1986.md)
- [§52.1987. Significant deterioration of air quality.](/cfr/40/52.1987.md)
- [§52.1988. Air contaminant discharge permits.](/cfr/40/52.1988.md)
- [§52.1989-52.2019. Reserved](/cfr/40/52.1989-52.2019.md)