Deposition and spatial distribution of insecticides following fogger, perimeter sprays, spot sprays, and crack-and-crevice applications for treatment and control of indoor pests

The indoor surface deposition and distribution of insecticides applied as foggers, baseboard or perimeter sprays, spot sprays and crack-and-crevice sprays represent distinct pathways of potential unintentional and unavoidable residential pesticide exposure of children and adults. Fogger, perimeter spray, crack-and-crevice, and spot sprays using registered commercial products were studied using three 5-part deposition plates positioned in unoccupied residences in Riverside, CA. Pesticide active ingredients included permethrin, chlorpyrifos, cyfluthrin, cypermethrin, and deltamethrin. Horizontal distribution factors of 100% (total release fogger in a small room), 50% (perimeter spray), 15% (crack-and-crevice), and 2% (spot spray) were assigned based upon application of selected commercial products by a licensed pest control operator and investigators who participated in these studies. This research reduces uncertainties associated with assessing human exposure following different application methods.