The Armed Forces Pest Management Board AFPMB has expressed interest in using the commercially available pyrethroid, transfluthrin, as a spatial repellent in ongoing efforts to protect military personnel from vector-borne diseases. Transfluthrin is currently used in malaria endemic areas as an indoor residual spray. It is effective at significantly reducing the number of bites from mosquitoes. However, little is known about the actual amounts of transfluthrin in the air when effective repellencybite reduction occurs, and if those concentrations are of concern to human health. The purpose of this research is to characterize airborne transfluthrin concentrations, when a known amount of transfluthrin liquid is applied to fabric and then subjected to a range of discrete temperatures. A l 7cm by 20 cm 340cm2 piece of transfluthrin treated fabric was placed in a temperature-controlled, enclosed space simulating a tent or hut. Air samples were taken at multiple locations within the space over an 8-hour day to track the movement of transfluthrin through the space. Experimentation was conducted at four temperatures 27-50 C. This research has demonstrated several relationships with the airborne concentration of transfluthrin. It increases as temperature and height are increased, it decreases as the distance from the source increases, and within the enclosed space used in this study, transfluthrin was well below the levels of current occupational exposure guidelines.