Home
gpo.gov
govinfo.gov

e-CFR Navigation Aids

Browse

Simple Search

Advanced Search

 — Boolean

 — Proximity

 

Search History

Search Tips

Corrections

Latest Updates

User Info

FAQs

Agency List

Incorporation By Reference

eCFR logo

Related Resources

Electronic Code of Federal Regulations

We invite you to try out our new beta eCFR site at https://ecfr.federalregister.gov. We have made big changes to make the eCFR easier to use. Be sure to leave feedback using the Feedback button on the bottom right of each page!

e-CFR data is current as of June 16, 2021

Title 40Chapter ISubchapter CPart 50


TITLE 40—Protection of Environment

CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

SUBCHAPTER C—AIR PROGRAMS

PART 50—NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS

rule
§50.1
Definitions.
§50.2
Scope.
§50.3
Reference conditions.
§50.4
National primary ambient air quality standards for sulfur oxides (sulfur dioxide).
§50.5
National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).
§50.6
National primary and secondary ambient air quality standards for PM10.
§50.7
National primary and secondary ambient air quality standards for PM2.5.
§50.8
National primary ambient air quality standards for carbon monoxide.
§50.9
National 1-hour primary and secondary ambient air quality standards for ozone.
§50.10
National 8-hour primary and secondary ambient air quality standards for ozone.
§50.11
National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator).
§50.12
National primary and secondary ambient air quality standards for lead.
§50.13
National primary and secondary ambient air quality standards for PM2.5.
§50.14
Treatment of air quality monitoring data influenced by exceptional events.
§50.15
National primary and secondary ambient air quality standards for ozone.
§50.16
National primary and secondary ambient air quality standards for lead.
§50.17
National primary ambient air quality standards for sulfur oxides (sulfur dioxide).
§50.18
National primary ambient air quality standards for PM2.5.
§50.19
National primary and secondary ambient air quality standards for ozone.
Appendix
Appendix A-1 to Part 50—Reference Measurement Principle and Calibration Procedure for the Measurement of Sulfur Dioxide in the Atmosphere (Ultraviolet Fluorescence Method)
Appendix
Appendix A-2 to Part 50—Reference Method for the Determination of Sulfur Dioxide in the Atmosphere (Pararosaniline Method)
Appendix
Appendix B to Part 50—Reference Method for the Determination of Suspended Particulate Matter in the Atmosphere (High-Volume Method)
Appendix
Appendix C to Part 50—Measurement Principle and Calibration Procedure for the Measurement of Carbon Monoxide in the Atmosphere (Non-Dispersive Infrared Photometry)
Appendix
Appendix D to Part 50—Reference Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere (Chemiluminescence Method)
Appendix
Appendix E to Part 50 [Reserved]
Appendix
Appendix F to Part 50—Measurement Principle and Calibration Procedure for the Measurement of Nitrogen Dioxide in the Atmosphere (Gas Phase Chemiluminescence)
Appendix
Appendix G to Part 50—Reference Method for the Determination of Lead in Total Suspended Particulate Matter
Appendix
Appendix H to Part 50—Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone
Appendix
Appendix I to Part 50—Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone
Appendix
Appendix J to Part 50—Reference Method for the Determination of Particulate Matter as PM10 in the Atmosphere
Appendix
Appendix K to Part 50—Interpretation of the National Ambient Air Quality Standards for Particulate Matter
Appendix
Appendix L to Part 50—Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere
Appendix
Appendix M to Part 50 [Reserved]
Appendix
Appendix N to Part 50—Interpretation of the National Ambient Air Quality Standards for PM2.5
Appendix
Appendix O to Part 50—Reference Method for the Determination of Coarse Particulate Matter as PM10-2.5 in the Atmosphere
Appendix
Appendix P to Part 50—Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone
Appendix
Appendix Q to Part 50—Reference Method for the Determination of Lead in Particulate Matter as PM10 Collected From Ambient Air
Appendix
Appendix R to Part 50—Interpretation of the National Ambient Air Quality Standards for Lead
Appendix
Appendix S to Part 50—Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide)
Appendix
Appendix T to Part 50—Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide)
Appendix
Appendix U to Part 50—Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

Need assistance?