The report gives results of the development of particulate emission factors based on cutoff size for inhalable particles for the nonferrous industry. After a review of available information characterizing particulate emissions from nonferrous plants, the data were summarized and rated in terms of reliability. Size specific emission factors were developed from these data for the major processes used in the manufacture of nonferrous metals. A detailed process description is presented with emphasis on factors affecting the generation of emissions. A replacement for Sections 7.1 (Primary Aluminum Production), 7.3 (Primary Copper Smelting), 7.6 (Primary Lead Smelting), 7.7 (Primary Zinc Smelting), and 7.11 (Secondary Lead Smelting) of EPA report AP-42. A Compilation of Air Pollutant Emissions Factors, was prepared, containing the size specific emission factors developed during the program.