This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was focused on Environmental Protection Agency (EPA) total particulate emission factors. There is no total particulate emission factor published for mote cleaner systems in the 1996 EPA AP-42. The objective of this study was to collect total particulate emission factor data for mote cleaner systems from cotton gins located in regions across the cotton belt using EPA-approved stack sampling methodology. The project plan included sampling seven cotton gins. Key factors for selecting specific cotton gins included: 1) facility location, 2) production capacity, 3) processing systems and 4) abatement technologies. Two gins with mote cleaner systems were sampled. The exhaust from one of the mote cleaner systems was combined with the module feeder dust system. The average production rate during testing was 32.7 and 47.0 bales/h for the stand alone mote cleaner system and mote cleaner and module feeder dust system, respectively. The average total particulate emission factor for the mote cleaner system that was not combined with another gin system (three total test runs) was 0.105 kg/227-kg bale (0.232 lb/500-lb bale). The average emission rate for this system was 3.46 kg/h (7.63 lb/h). The average total particulate emission factor for the mote cleaner system that was combined with the module feeder dust system (three total test runs) was 0.109 kg/bale (0.239 lb/bale). The average emission rate for this system was 5.10 kg/h (11.24 lb/h).