Measurements of ozone concentrations in onshore areas of Texas and Louisiana periodically exceed the national standard for eight-hour ozone in nonattainment areas, with the Beaumont-Port Arthur, Texas, and Baton Rouge, Louisiana, areas classified as marginal, and the Houston-Galveston-Brazoria, Texas, area classified as moderate. Shoreline and inland locations in Texas and Louisiana, as well as Mississippi, Alabama, and Florida, could potentially be influenced by emission sources in the Gulf of Mexico. The Minerals Management Service (MMS) is responsible for determining if air pollutant emissions from Outer Continental Shelf (OCS) oil and natural gas platforms and other sources in the Gulf of Mexico influence the ozone attainment and nonattainment status of onshore areas. Ozone forms in the presence of sunlight from the reaction of volatile organic compounds (VOC) and oxides of nitrogen (NOx).