Kinetic study of chlorine dioxide gas disinfection on bacillus Atrophaeus spores

• Main Authors: Chen Tsung-Ming, 陳宗明
• Other Authors: Wang Wen-Hua
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/62966581039444165819

碩士 === 中華醫事科技大學 === 生物安全衛生研究所 === 96 === The aim of this experiment is to study the inactivation kinetic of Bacillus atrophaeus spores with chlorine dioxide gas in a test chamber. Bacillus atrophaeus spores strips were treated with chlorine dioxide gas which was aerosolized by ultrasonic nebulizer from chlorine dioxide solution and introduced into test chamber at different concentrations in different time to determine the inactivated rate using enumeration and fractionation analysis of tryptic soy broth (TSB) and tryptic soy agar (TSA). The exposure dose was calculated by Harber’s rule based on chlorine dioxide gas concentration which was measured by detector tubes and total exposure time to establish D-value (Decimal reduction time) from inactivation curve. It was found that the half life of chlorine dioxide gas was less than 5 hr (300 min) at 20~25 ℃ under 90~95% relative humidity. The number of survived spores after exposure to chlorine dioxide gas followed an exponential decrease with increasing exposure concentration and contact time. The D-value of Bacillus atrophaeus spores treated with 100 ppm chlorine dioxide gas was about 60 minutes in this study. The results from this study suggest that gaseous chlorine dioxide should be a highly effective decontaminating agent for Bacillus atrophaeus spores within 2hr exposure time to determine the sterilization cycle achieving 6-log reduction.