CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS > SUBPART A—General Provisions (§52.01 to §52.36) > 52.14—State ambient air quality standards.

52.14—State ambient air quality standards.

Any ambient air quality standard submitted with a plan which is less stringent than a national standard is not considered part of the plan.