Following its 2008 mandatory review for ozone, EPA set primary and secondary NAAQS at 0.075 parts per million (ppm) during an eight-hour averaging time (the 2008 NAAQS). These NAAQS generated significant controversy, resulting in a number of lawsuits, many of which were eventually consolidated into the "Ozone NAAQS Litigation." In response to the litigation and public concern, EPA requested the litigation be held in abeyance by the D.C. Circuit Court while EPA developed a draft reconsideration of the 2008 NAAQS. Similarly, EPA placed implementation of the 2008 NAAQS on hold while it reconsidered the standards.