Sterilization and protein treatment using oxygen radicals produced by RF discharge

Sterilization of medical equipments was performed using low pressure RF inductively coupled plasma. Oxygen radicals as oxidizing agents for sterilization were produced from oxygen or water vapor. Generation of atomic oxygen and OH radical was confirmed by light emission spectra of the plasma. The pressure in the discharge region was varied periodically during sterilization in order to produce radicals effectively and to penetrate the produced radicals into tiny gaps. Medium sheets for microbial detection indicated that the decimal reduction value of active bacillus was 21 minutes and 26 minutes using oxygen plasma and water vapor plasma, respectively. Biological indicators clarified that the sterilization of bacilli spore was successful for the treatment time of 90 minutes.