Application of Electrostatic and Backpack Sprayer Systems for Decontamination of Building Materials Contaminated with Malathion: Assessment and Evaluation Report [open pdf - 1MB]
"This project supports the mission of the U.S. Environmental Protection Agency Office of Research and Development's Homeland Security Research Program (HSRP) by providing information relevant to the decontamination of areas contaminated as a result of a chemical contamination incident. The primary objective of this investigation was to evaluate the use of two different types of spray systems to supply a decontaminant to a surface. The evaluation tests described in this report determined the effectiveness of an electrostatic sprayer system in delivery of a decontaminant to clean a building material contaminated with a toxic chemical. Efficacy results using the electrostatic sprayer for neutralization of the chemical from three building materials were compared to the results obtained using the more traditional backpack sprayer system. Electrostatic sprayers are more efficient than conventional spray systems, and they deliver a more uniform distribution of the liquid on an (uneven) surface. In this study, the targeted decontaminant was full-strength bleach and the chemical was malathion, a pesticide and surrogate for the chemical warfare agent (CWA) O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX). Full-strength bleach was selected over more traditional diluted bleach (typically 10 fold dilution) based on outcomes from previous bench scale research in which poorer decontamination efficacy was observed against materials contaminated with CWAs HD and VX . Malathion was applied uniformly as a thin film or as more discrete droplets of low or high concentration. The impact on the efficacy of these different malathion distribution patterns was also investigated. Three building material substrates were included, namely, stainless steel, wood, and vinyl."
Environmental Protection Agency: https://cfpub.epa.gov/