Surface decontamination using atmospheric oxygen-argon plasma

This study reports on the efficacy of atmospheric oxygen-argon plasma for bio-decontamination or surface sterilization of infectious agents, such as Bacillus anthracis [Sterne] (Anthrax), MS-2 bacteriophage, and E coli. A 10- second exposure (RF power 77 W, 29.5 mL O₂/min, 28 L Ar/min) on the B. a. spores revealed an average post-exposure log reduction (LR) value of 2.7, whereas a 20-second treatment yielded a log 9.9 kill. The effectiveness of the oxygen-argon plasma is believed to be attributed to the generation of free radicals, specifically highly reactive oxygen atom or hydroxyl radicals. The mechanism of radical attack of the microorganisms is discussed.