The objective of the work reported in this paper was to test the dust control effectiveness of an overhead air supplied island (oasis). This device provides an envelope of clean air for dust protection for individual work stations in environments where other engineering controls are not practical or available. A fan-powered filtration unit and a unique air distribution system provide 6,000 ft3/min of clean air over the operator. Ram-1 light-scattering dust monitors were used to measure dust concentrations as the unit was turned on and off at a bagging machine operator's work station at two industrial silica plants. Dust concentration reductions at the operator's breathing zone were 98 and 82 pct, and dust concentrations never exceeded 0.06 Mg/m3 during operation of the oasis. The oasis has potential applications in many industrial areas where dust exposures are excessive. It is a simple, self- contained unit which can reduce worker exposure to dust at a work station. In addition to the health benefits of the oasis, worker comfort is improved in the clean and heated airstream. Maintenance of the unit is minimal. Another significant advantage of this approach to operator protection is that the unit is not part of the process, and thus production is unaffected.