This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2006 and again in 2013, the United States (U.S.) Environmental Protection Agency (EPA) published a more stringent National Ambient Air Quality Standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent need to collect additional cotton gin emissions data to address current regulatory issues, because EPA AP-42 cotton gin PM2.5 emission factors were limited. In addition, EPA AP-42 included combined 1st and 2nd stage mote system PM10 (particulate matter with nominal diameter less than or equal to 10 µm) and total particulate emission factors and not individual mote system emission factors. The objective of this study was to characterize particulate emissions for 2nd stage mote systems from cotton gins across the cotton belt based on particle size distribution analysis of total particulate samples from EPA-approved stack sampling methods. Average measured PM2.5, PM6, and PM10 emission factors based on the mass and particle size analyses of EPA Method 17 total particulate filter and wash samples from five gins (15 total test runs) were 0.00030 kg/227-kg bale (0.00067 lb/500-lb bale), 0.0024 kg/bale (0.0054 lb/bale), and 0.0039 kg/bale (0.0087 lb/bale), respectively. The 2nd stage mote system particle size distributions were characterized by an average mass median diameter of 16.1 µm (aerodynamic equivalent diameter). Based on system average emission factors, the ratio of PM2.5 to total particulate was 2.87%, PM6 to total particulate was 23.0%, and PM10 to total particulate was 23.0%.