In general, the EPA managed the CASAC and Council in accordance with applicable statutes and regulations. These regulations allow agencies discretion in choosing federal advisory committee members and achieving balance. We reviewed 47 CASAC and Council member appointments, including all ozone panel appointments for the last two ozone standard reviews. We found that the EPA has adequate procedures for identifying potential ethics concerns, including financial conflicts of interest, independence issues and appearances of a lack of impartiality. However, the EPA can better document its decisions on selecting members with independence and partiality concerns. This would allow for better transparency, thus giving assurance that CASAC and the Council provide independent and objective advice to the Administrator on such important decisions as setting ambient air standards. We also identified one instance where agency procedures involving a potential conflict of interest were not followed. We also reviewed the peer review process for three EPA-developed analyses included in scientific assessments peer reviewed by the CASAC. Peer review is one method for enhancing the quality and credibility of the government's scientific information. One of these analyses was not peer reviewed in accordance with Office of Management and Budget and agency guidance. The EPA's National Center for Environmental Assessment did not have a formal process for determining whether such analyses were subject to OMB requirements and the EPA's peer review guidance before public dissemination.