Reprint of: Sterilization of small vial using electron cyclotron resonance plasma

• Published in: Vacuum Vol. 167; pp. 586 - 590
• Main Authors: Nishikawa, Tatsuya, Abe, Norihito, Yonesu, Akira, Hayashi, Nobuya
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2019
• Subjects: ECR plasma; Plasma sterilization; Pulsed microwave; Small vial; Plasma sterilization; ECR plasma; Small vial; Pulsed microwave
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2019.03.044

The sterilization of a small vial using electron cyclotron resonance (ECR) plasma was investigated. The ECR plasma was generated throughout the inside of the small vial, which was sealed with nonwoven fabric, by using magnetic configuration in which the ECR point was located inside the small vial. Moreover, it was demonstrated that the temperature of the small vial was finely controlled by the pulse width and pulse frequency of the pulsed microwave power. A biological indicator (BI), Geobacillus Stearothermophilus, containing 1 × 105 spores present inside the small vial was successfully inactivated in a total treatment time of about 14 min while maintaining treatment temperature of less than 65 °C. •Inner surface of vial is sterilized using ECR plasma.•Low temperature sterilization is achieved by pulsed drive of ECR plasma.•Sterilization was confirmed at locations other than the ECR point in the vial.•Plasma is generated only inside the vial by controlling the magnetic field distribution.