---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchC/part97"
level: "part"
label: "Part 97"
heading: "Federal Nox Budget Trading Program, Cair Nox and So2 Trading Programs, Csapr Nox and So2 Trading Programs, and Texas So2 Trading Program"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchC-part97"
sections_count: 439
---

# Part 97 — Federal Nox Budget Trading Program, Cair Nox and So2 Trading Programs, Csapr Nox and So2 Trading Programs, and Texas So2 Trading Program

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter C — Air Programs

## Contents

- [Subpart A — NO X Budget Trading Program General Provisions](/cfr/40/chI-subchC-part97-subpartA.md)
- [Subpart B — NO X Authorized Account Representative for NO X Budget Sources](/cfr/40/chI-subchC-part97-subpartB.md)
- [Subpart C — Permits](/cfr/40/chI-subchC-part97-subpartC.md)
- [Subpart D — Compliance Certification](/cfr/40/chI-subchC-part97-subpartD.md)
- [Subpart E — NO X Allowance Allocations](/cfr/40/chI-subchC-part97-subpartE.md)
- [Subpart F — NO X Allowance Tracking System](/cfr/40/chI-subchC-part97-subpartF.md)
- [Subpart G — NO X Allowance Transfers](/cfr/40/chI-subchC-part97-subpartG.md)
- [Subpart H — Monitoring and Reporting](/cfr/40/chI-subchC-part97-subpartH.md)
- [Subpart I — Individual Unit Opt-ins](/cfr/40/chI-subchC-part97-subpartI.md)
- [Subpart J — Appeal Procedures](/cfr/40/chI-subchC-part97-subpartJ.md)
- [Subpart AA — CAIR NO X Annual Trading Program General Provisions](/cfr/40/chI-subchC-part97-subpartAA.md)
- [Subpart BB — CAIR Designated Representative for CAIR NO X Sources](/cfr/40/chI-subchC-part97-subpartBB.md)
- [Subpart CC — Permits](/cfr/40/chI-subchC-part97-subpartCC.md)
- [Subpart DD — Subpart DD [Reserved]](/cfr/40/chI-subchC-part97-subpartDD.md)
- [Subpart EE — CAIR NO X Allowance Allocations](/cfr/40/chI-subchC-part97-subpartEE.md)
- [Subpart FF — CAIR NO X Allowance Tracking System](/cfr/40/chI-subchC-part97-subpartFF.md)
- [Subpart GG — CAIR NO X Allowance Transfers](/cfr/40/chI-subchC-part97-subpartGG.md)
- [Subpart HH — Monitoring and Reporting](/cfr/40/chI-subchC-part97-subpartHH.md)
- [Subpart II — CAIR NO X Opt-In Units](/cfr/40/chI-subchC-part97-subpartII.md)
- [Subpart AAA — CAIR SO 2 Trading Program General Provisions](/cfr/40/chI-subchC-part97-subpartAAA.md)
- [Subpart BBB — CAIR Designated Representative for CAIR SO 2 Sources](/cfr/40/chI-subchC-part97-subpartBBB.md)
- [Subpart CCC — Permits](/cfr/40/chI-subchC-part97-subpartCCC.md)
- [Subpart DDD-EEE — Subparts DDD-EEE [Reserved]](/cfr/40/chI-subchC-part97-subpartDDD-EEE.md)
- [Subpart FFF — CAIR SO 2 Allowance Tracking System](/cfr/40/chI-subchC-part97-subpartFFF.md)
- [Subpart GGG — CAIR SO 2 Allowance Transfers](/cfr/40/chI-subchC-part97-subpartGGG.md)
- [Subpart HHH — Monitoring and Reporting](/cfr/40/chI-subchC-part97-subpartHHH.md)
- [Subpart III — CAIR SO 2 Opt-in Units](/cfr/40/chI-subchC-part97-subpartIII.md)
- [Subpart AAAA — CAIR NO X Ozone Season Trading Program General Provisions](/cfr/40/chI-subchC-part97-subpartAAAA.md)
- [Subpart BBBB — CAIR Designated Representative for CAIR NO X Ozone Season Sources](/cfr/40/chI-subchC-part97-subpartBBBB.md)
- [Subpart CCCC — Permits](/cfr/40/chI-subchC-part97-subpartCCCC.md)
- [Subpart DDDD — Subpart DDDD [Reserved]](/cfr/40/chI-subchC-part97-subpartDDDD.md)
- [Subpart EEEE — CAIR NO X Ozone Season Allowance Allocations](/cfr/40/chI-subchC-part97-subpartEEEE.md)
- [Subpart FFFF — CAIR NO X Ozone Season Allowance Tracking System](/cfr/40/chI-subchC-part97-subpartFFFF.md)
- [Subpart GGGG — CAIR NO X Ozone Season Allowance Transfers](/cfr/40/chI-subchC-part97-subpartGGGG.md)
- [Subpart HHHH — Monitoring and Reporting](/cfr/40/chI-subchC-part97-subpartHHHH.md)
- [Subpart IIII — CAIR NO X Ozone Season Opt-in Units](/cfr/40/chI-subchC-part97-subpartIIII.md)
- [Subpart AAAAA — CSAPR NO X Annual Trading Program](/cfr/40/chI-subchC-part97-subpartAAAAA.md)
- [Subpart BBBBB — CSAPR NO X Ozone Season Group 1 Trading Program](/cfr/40/chI-subchC-part97-subpartBBBBB.md)
- [Subpart CCCCC — CSAPR SO 2 Group 1 Trading Program](/cfr/40/chI-subchC-part97-subpartCCCCC.md)
- [Subpart DDDDD — CSAPR SO 2 Group 2 Trading Program](/cfr/40/chI-subchC-part97-subpartDDDDD.md)
- [Subpart EEEEE — CSAPR NO X Ozone Season Group 2 Trading Program](/cfr/40/chI-subchC-part97-subpartEEEEE.md)
- [Subpart FFFFF — Texas SO 2 Trading Program](/cfr/40/chI-subchC-part97-subpartFFFFF.md)
- [Subpart GGGGG — CSAPR NO X Ozone Season Group 3 Trading Program](/cfr/40/chI-subchC-part97-subpartGGGGG.md)