CC-10-006: Proposal to Modify the National Ambient Air Quality Standards for Ozone

In the January 19, 2010 Federal Register, EPA proposes to revise the National Ambient Air Quality Standards (NAAQS) for ozone. The current primary and secondary National Ambient Air Quality Standard for ozone is an 8-hour average of 0.075 ppm. The standard is met if the average annual 4th highest daily 8-hour maximum concentration is less than 0.075 ppm over a three year period. EPA is proposing to revise both the primary and secondary standard.