This report presents a description of the activities and accomplishments of the American Society for Testing and Materials' U.S. Technical Advisory Group (TAG) to the International Standards Organization's Technical Committee 146 on Air Quality. The purpose of the Tag is to represent the United States of America on matters involving the development and implementation of international standards on air pollution measurement and control. The TAG, which consists of technical experts from industry, government and academia, participate in the development of standards by writing, reviewing, and voting on adoption. The TAG has been instrumental in producing a large number of international standards based on EPA methods and other methods acceptable for use in the United States. This report describes the organization of ISO TC 146 and summarizes the activities of the TAG over the three-year period of Cooperative Agreement Grant CR824457, which provided funding for non-government technical representatives from the United States to travel to ISO and TAG meetings to participate in the development of standards to monitor and control air pollutants. Such standards help assure the maintenance of acceptable air quality for all nations.