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Code · CFR · Title 40 — Protection of Environment · Part 50 · § 50.19

§ 50.19. National primary and secondary ambient air quality standards for ozone.

221 words·~1 min read·/us/cfr/t40/s§ 50.19·

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(a)The level of the national 8-hour primary ambient air quality standard for ozone
(O3)is 0.070 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 O3 ambient air quality standard is 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 0.070 ppm, as determined in accordance with appendix U to this part.
(c)The level of the national secondary ambient air quality standard for O3 is 0.070 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.
(d)The 8-hour secondary O3 ambient air quality standard is 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 0.070 ppm, as determined in accordance with appendix U to this part. [80 FR 65452, Oct. 26, 2015]
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§ 50.19
National primary and secondary ambient air quality standards for ozone.
Fed. Reg.×93
C.F.R.×1
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