Occupational cotton dust control technology was evaluated in 10 oil mills throughout the cotton belt of the U.S. This evaluation was restricted to mechanical portions of each mill: seed cleaning, delintering, hulling and separating, and linter baling. Based on the process machinery observed in these mills, a 500 ton/day model cottonseed oil mill was designed, The occupational dust control systems for this mill were based on current state-of-the-art technology observed during this project. Further improvements based on readily available air pollution control devices have been incorporated. In order to achieve minimal respirable dust concentrations in the mill, all dust emission points have been enclosed to the maximal extent consistent with efficient plant operations. The various processing areas in the mill were designed with negative pressure dust control systems separate from the general ventilation system. The dust control system includes coarse dust removal by high-efficiency cyclones whose effluent discharges into pulse-jet fabric filter baghouses operated at an air-to-cloth ratio of 20.-1. The emission control system for saw-type delinter systems were divided into small units to reduce the deleterious effects of fires.