Sterilization using OH radical produced by atmospheric discharge plasma

Summary form only given, as follows. In food processing, medical treatment, etc., safe and high speed dry type sterilizing method has been required. Using an ac silent discharge, hydrogen peroxide is dissociated to OH radicals. Recently, OH radicals have been used for the sterilization of medical instruments using a low pressure glow discharge. Since the lifetime of an OH radical is very short (less than 1 ms), safety in case of a leak is high. The main advantage of this method is that the final products are water and oxygen, and that there is no negative impact on the environment. In this study, we have developed surface sterilization equipment using an atmospheric pressure electric discharge. An effective sterilization performance has been achieved for a short treatment time by decomposing hydrogen peroxide by the discharge. The sterilization performance against Bacillus subtilus spore, E. Coli., and common germs on the surface of a plastic material has been studied. The six orders of decrease in the viability of the B. Subtilus spore, common germs and E. Coli was 300 sec, 120 sec, 90 sec, respectively, when a 1 kHz ac silent discharge was used. The proposed method can possibly be applied in food processing.