ARS | Publication request: Droplet size characterization of hand-held atomization equipment typically used in vector control

Submitted to: American Mosquito Control Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2007
Publication Date: September 5, 2007
Citation: Hoffmann, W.C., Walker, T.W., Smith, V.L., Martin, D.E., Fritz, B.K. 2007. Droplet-size characterization of handheld atomization equipment typically used in vector control. Journal of the American Mosquito Control Association. 23(3):315-320.

Interpretive Summary: Numerous spray machines are used to apply products for the control of human disease vectors, such as mosquitoes and flies, and the selection and setup of these machines significantly affects the level of control achieved during an application. The droplet spectra produced by five different machines were evaluated with commonly-used insecticides. There were significant differences in the droplet sizes produced by these machines and only one sprayer complied with label requirements for droplet size. Results from this study allow users of these sprayers to confidently select the sprayer and operational parameters that best fit their application situation.

Technical Abstract: The atomization characteristics from four hand-held sprayers (Leco P-1, Colt ULV Aerosol Generator, UlVAFAN MK2, Turbair ElectraFan 12) and a Stihl SR400 backpack sprayer were evaluated using water- and oil-based solutions. The effects on droplet size spectrum for three insecticides (Tempo SC Ultra, Anvil 10+10, and Aqua-Reslin) were also evaluated. Generic solutions were used to simulate the physical properties of the active ingredient solutions. There were significant differences in the droplet spectrum generated by the different sprayers. The volume median diameter of the equipment tested ranged from 14.9-90.5 µm for the water-based solutions and 11.7-92.4 µm for the oil-based solutions. The Colt ULV sprayer was the only one tested that complied with the label requirements from Anvil 10+10 applications. The information presented will allow equipment operators to make an informed decision when selecting equipment and operational parameters.