An overview of research using the one atmosphere uniform glow discharge plasma (OAUGDP) for sterilization of surfaces and materials

The medical, food processing, and heating, ventilating, and air conditionin g industries are searching for improved pasteurization, disinfection, and s terilization technologies, Candidate techniques must deal with and overcome such problems as thermal sensitivity and destruction by heat, formation of toxic by-products, costs, and inefficiency in performance. We report the r esults of a plasma source, the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP), which operates at atmospheric pressure in air and produces antim icrobial active species at room temperature. OAUGDP exposures have reduced log numbers of Gram negative and Gram positive bacteria, bacterial endospor es, yeast, and bacterial viruses on a variety of surfaces. The nature of th e surface influenced the degree of lethality, with microorganisms on polypr opylene being most sensitive, followed by glass, and cells embedded in agar , Experimental results showed at least a 5 log(10) CFU reduction in bacteri a within a range of 50-90 s of exposure. After 10-25 s of exposure, macromo lecular leakage and bacterial fragmentation were observed, Vulnerability of cell membranes to reactive Oxygen species (ROC) is hypothesized. Results f rom several noval OAUGDP configurations are presented, including a remote e xposure reactor (RER) which uses transported active species to sterilize ma terial located more than 20 cm from the plasma generation site, and a secon d planar electrode configuration developed for air filter sterilization, Ap plications of these technologies to the healthcare industry, the food indus try, and decontaminating surfaces compromised by biological warfare agents are discussed.