40 CFR 50.15
§ 50.15 National primary and secondary ambient air quality standards for ozone.
United States · 40 CFR — Protection of Environment · Status: effective
Cite this
- Citation
- 40 CFR 50.15, § 50.15 National primary and secondary ambient air quality standards for ozone, United States, version 1 as recorded 2026-07-09, yourstate.us, https://yourstate.us/provision/169705
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Full text
(a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts per million (ppm), daily maximum 8-hour average, measured by a reference method based on appendix D to this part and designated in accordance with part 53 of this chapter or an equivalent method designated in accordance with part 53 of this chapter.
(b) The 8-hour primary and secondary O3 ambient air quality standards are met at an ambient air quality monitoring site when the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentration is less than or equal to 0.075 ppm, as determined in accordance with appendix P to this part.
Legislative history
This is a federal regulation, adopted through agency rulemaking under the Administrative Procedure Act — not enacted by a recorded vote of Congress.