President Obama announced on September 2 that his administration was withdrawing the draft ozone ambient air quality standards that the U.S. Environmental Protection Agency (EPA) had prepared and was in the process of issuing as new regulations. The new regulations, had they become final, would have resulted in stricter standards related to ozone. This action does not relieve companies of compliance with any current air pollution control requirements because the withdrawn standards had not been adopted as final. Moreover, the withdrawal may result in only a temporary respite from new ozone standards because the Clean Air Act requires EPA to reconsider ozone standards in 2013. In addition, the administration has clarified that it intends to proceed to the next steps in implementing standards announced in 2008.

Ground-level ozone is formed by the combination of volatile organic compounds and nitrogen oxides in the presence of sunlight, and has been linked to respiratory health problems including decreased lung function and aggravated asthma. The Clean Air Act requires EPA to set national ambient air quality standards for ozone and five other air pollutants, which states must achieve through imposing emission-control requirements on industrial facilities, vehicles, and other sources of the air pollutants in areas that do not attain the air quality standards.