Environmental Protection Agency Administrator Stephen Johnson announced March 12 that he had signed a more stringent eight-hour standard for ozone, the first revision of the standard in more than a decade, and called for changes to the Clean Air Act that would allow the EPA to consider cost and feasibility when developing air quality regulations.

The new standard was changed from the current level of 80 parts per billion (ppb) to 75 ppb. Johnson says the new standard, based on a review of the current science on the effects of ozone on public health, is the toughest national standard ever enacted for ozone.