Litigation associated with the current NAAQS review may involve schedules for the review as well as challenges to the final decisions, and court decisions in these matters.  

• U.S. Court of Appeals, DC Circuit Court Decision Upholding the August 2011 Carbon Monoxide NAAQS (PDF)(11 pp, 52 K, April 2014, About PDF)
• Court Order extending dates for proposed and final rulemaking (PDF)(1 pg, 31 K, August 2010 About PDF)
• Order Establishing Schedule to Review NAAQS for Carbon Monoxide (PDF)(3 pp, 31 K, November 2008, About PDF)

You may also be interested in other documents from the current carbon monoxide NAAQS review.