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
50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.
(a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by a reference method based on appendix D to this part and designated in accordance with part 53 of this chapter, is 0.08 parts per million (ppm), daily maximum 8-hour average.
(b) The 8-hour primary and secondary ozone ambient air quality standards are met at an ambient air quality monitoring site when the average of the annual fourth-highest daily maximum 8-hour average ozone concentration is less than or equal to 0.08 ppm, as determined in accordance with appendix I to this part.
[62 FR 38894, July 18, 1997]