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40 CFR 50.1 · Definitions.
40 CFR 50.2 · Scope.
40 CFR 50.3 · Reference conditions.
40 CFR 50.4 · National primary ambient air quality standards for sulfur oxides (sulfur dioxide).
40 CFR 50.5 · National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).
40 CFR 50.6 · National primary and secondary ambient air quality standards for PM10.
40 CFR 50.7 · National primary and secondary ambient air quality standards for PM2.5.
40 CFR 50.8 · National primary ambient air quality standards for carbon monoxide.
40 CFR 50.9 · National 1-hour primary and secondary ambient air quality standards for ozone.
40 CFR 50.10 · National 8-hour primary and secondary ambient air quality standards for ozone.
40 CFR 50.11 · National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator).
40 CFR 50.12 · National primary and secondary ambient air quality standards for lead.
40 CFR 50.13 · National primary and secondary ambient air quality standards for PM2.5.
40 CFR 50.14 · Treatment of air quality monitoring data influenced by exceptional events.
40 CFR 50.15 · National primary and secondary ambient air quality standards for ozone.
40 CFR 50.16 · National primary and secondary ambient air quality standards for lead.
40 CFR 50.17 · National primary ambient air quality standards for sulfur oxides (sulfur dioxide).
40 CFR 50.18 · National primary ambient air quality standards for PM2.5.
40 CFR 50.19 · National primary and secondary ambient air quality standards for ozone.
40 CFR 50.20 · National primary ambient air quality standards for PM2.5.
40 CFR 50.21 · National secondary ambient air quality standards for sulfur oxides (sulfur dioxide).
40 CFR Appendix A-1 to Part 50 · Appendix A-1 to Part 50—Reference Measurement Principle and Calibration Procedure for the Measurement of Sulfur Dioxide in the Atmosphere (Ultraviolet Fluorescence Method)
40 CFR Appendix A-2 to Part 50 · Appendix A-2 to Part 50—Reference Method for the Determination of Sulfur Dioxide in the Atmosphere (Pararosaniline Method)
40 CFR Appendix B to Part 50 · Appendix B to Part 50—Reference Method for the Determination of Suspended Particulate Matter in the Atmosphere (High-Volume Method)
40 CFR Appendix C to Part 50 · Appendix C to Part 50—Measurement Principle and Calibration Procedure for the Measurement of Carbon Monoxide in the Atmosphere (Non-Dispersive Infrared Photometry)
40 CFR Appendix D to Part 50 · Appendix D to Part 50—Reference Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere (Chemiluminescence Method)
40 CFR Appendix E to Part 50 · Appendix E to Part 50 [Reserved]
40 CFR Appendix F to Part 50 · Appendix F to Part 50—Measurement Principle and Calibration Procedure for the Measurement of Nitrogen Dioxide in the Atmosphere (Gas Phase Chemiluminescence)
40 CFR Appendix G to Part 50 · Appendix G to Part 50—Reference Method for the Determination of Lead in Total Suspended Particulate Matter
40 CFR Appendix H to Part 50 · Appendix H to Part 50—Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone
40 CFR Appendix I to Part 50 · Appendix I to Part 50—Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone
40 CFR Appendix J to Part 50 · Appendix J to Part 50—Reference Method for the Determination of Particulate Matter as PM10 in the Atmosphere
40 CFR Appendix K to Part 50 · Appendix K to Part 50—Interpretation of the National Ambient Air Quality Standards for Particulate Matter
40 CFR Appendix L to Part 50 · Appendix L to Part 50—Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere
40 CFR Appendix M to Part 50 · Appendix M to Part 50 [Reserved]
40 CFR Appendix N to Part 50 · Appendix N to Part 50—Interpretation of the National Ambient Air Quality Standards for PM2.5
40 CFR Appendix O to Part 50 · Appendix O to Part 50—Reference Method for the Determination of Coarse Particulate Matter as PM10-2.5 in the Atmosphere
40 CFR Appendix P to Part 50 · Appendix P to Part 50—Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone
40 CFR Appendix Q to Part 50 · Appendix Q to Part 50—Reference Method for the Determination of Lead in Particulate Matter as PM10 Collected From Ambient Air
40 CFR Appendix R to Part 50 · Appendix R to Part 50—Interpretation of the National Ambient Air Quality Standards for Lead
40 CFR Appendix S to Part 50 · Appendix S to Part 50—Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide)
40 CFR Appendix T to Part 50 · Appendix T to Part 50—Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide)
40 CFR Appendix U to Part 50 · Appendix U to Part 50—Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone
40 CFR 51.1 · Who is responsible for actions described in this subpart?
40 CFR 51.5 · What tools are available to help prepare and report emissions data?
40 CFR 51.10 · [Reserved]
40 CFR 51.15 · What data does my state need to report to EPA?
40 CFR 51.20 · What are the emission thresholds that separate point and nonpoint sources?
40 CFR 51.25 · What geographic area must my state's inventory cover?
40 CFR 51.30 · When does my state report which emissions data to EPA?
40 CFR 51.35 · How can my state equalize the emission inventory effort from year to year?
40 CFR 51.40 · In what form and format should my state report the data to EPA?
40 CFR 51.45 · Where should my state report the data?
40 CFR 51.50 · What definitions apply to this subpart?
40 CFR Appendix A to Subpart A of Part 51 · Appendix A to Subpart A of Part 51—Tables
40 CFR 51.100 · Definitions.
40 CFR 51.101 · Stipulations.
40 CFR 51.102 · Public hearings.
40 CFR 51.103 · Submission of plans, preliminary review of plans.
40 CFR 51.104 · Revisions.
40 CFR 51.105 · Approval of plans.
40 CFR 51.110 · Attainment and maintenance of national standards.
40 CFR 51.111 · Description of control measures.
40 CFR 51.112 · Demonstration of adequacy.
40 CFR 51.113 · [Reserved]
40 CFR 51.114 · Emissions data and projections.
40 CFR 51.115 · Air quality data and projections.
40 CFR 51.116 · Data availability.
40 CFR 51.117 · Additional provisions for lead.
40 CFR 51.118 · Stack height provisions.
40 CFR 51.119 · Intermittent control systems.
40 CFR 51.120 · Requirements for State Implementation Plan revisions relating to new motor vehicles.
40 CFR 51.121 · Findings and requirements for submission of State implementation plan revisions relating to emissions of nitrogen oxides.
40 CFR 51.122 · Emissions reporting requirements for SIP revisions relating to budgets for NOX emissions.
40 CFR 51.123 · Findings and requirements for submission of State implementation plan revisions relating to emissions of oxides of nitrogen pursuant to the Clean Air Interstate Rule.
40 CFR 51.124 · Findings and requirements for submission of State implementation plan revisions relating to emissions of sulfur dioxide pursuant to the Clean Air Interstate Rule.
40 CFR 51.125 · [Reserved]
40 CFR 51.126 · Determination of widespread use of ORVR and waiver of CAA section 182(b)(3) Stage II gasoline vapor recovery requirements.
40 CFR 51.150 · Classification of regions for episode plans.
40 CFR 51.151 · Significant harm levels.
40 CFR 51.152 · Contingency plans.
40 CFR 51.153 · Reevaluation of episode plans.
40 CFR 51.160 · Legally enforceable procedures.
40 CFR 51.161 · Public availability of information.
40 CFR 51.162 · Identification of responsible agency.
40 CFR 51.163 · Administrative procedures.
40 CFR 51.164 · Stack height procedures.
40 CFR 51.165 · Permit requirements.
40 CFR 51.166 · Prevention of significant deterioration of air quality.
40 CFR 51.190 · Ambient air quality monitoring requirements.
40 CFR 51.210 · General.
40 CFR 51.211 · Emission reports and recordkeeping.
40 CFR 51.212 · Testing, inspection, enforcement, and complaints.
40 CFR 51.213 · Transportation control measures.
40 CFR 51.214 · Continuous emission monitoring.
40 CFR 51.230 · Requirements for all plans.
40 CFR 51.231 · Identification of legal authority.
40 CFR 51.232 · Assignment of legal authority to local agencies.
40 CFR 51.240 · General plan requirements.
40 CFR 51.241 · Nonattainment areas for carbon monoxide and ozone.