- 著者
- SATOSHI FUKUZAKI
- 出版者
- The Society for Antibacterial and Antifungal Agents, Japan
- 雑誌
- Biocontrol Science (ISSN:13424815)
- 巻号頁・発行日
- vol.11, no.4, pp.147-157, 2006-12-10 (Released:2011-02-23)
- 参考文献数
- 72
- 被引用文献数
- 169 392
Sodium hypochlorite (NaOCI) is the most widely used disinfectant in the food industry despite the increasing availability of other disinfectants. Sodium hypochlorite fulfills many requirements as the ideal disinfectant and furthermore it has an excellent cleaning action. The effectiveness of sodium hypochlorite in the cleaning and disinfection processes depends on the concentration of available chlorine and the pH of the solution. Hypochlorous acid (HOCI) is a weak acid and dissociates to the hypochlorite ion (-OCI) and proton (H+) depending on the solution pH. It is generally believed that HOCI is the active species in the germicidal action, whereas the concentration of -OCI is a key factor determining the cleaning efficiency. This implies that the optimal pH region of the germicidal activity of sodium hypochlorite differs from that of its cleaning activity. This paper describes the theory and practice of the cleaning and disinfecting operations based on the use of sodium hypochlorite solution.
2 0 0 0 OA Effect of pH on the Efficacy of Sodium Hypochlorite Solution as Cleaning and Bactericidal Agents
- 著者
- Satoshi FUKUZAKI Hiromi URANO Sadako YAMADA
- 出版者
- The Surface Finishing Society of Japan
- 雑誌
- 表面技術 (ISSN:09151869)
- 巻号頁・発行日
- vol.58, no.8, pp.465, 2007 (Released:2008-02-21)
- 参考文献数
- 34
- 被引用文献数
- 20 23
The efficacy of sodium hypochlorite (NaOCl) solution as a cleaning and bactericidal agent against Pseudomonas fluorescens was studied as a function of pH. Alumina (Al2O3) particles on which P. fluorescens cells were irreversibly adhered were cleaned with NaOCl solutions of pH 5 to 12 containing free available chlorine (AC) of 120 to 1000mg/L. The efficiency of the removal of P. fluorescens cells from the Al2O3 surfaces increased with increasing pH and the AC concentration. It was found that the efficacy of NaOCl solution as a cleaning agent depended on the concentration of the dissociated hypochlorite ion (-OCl). On the other hand, the bactericidal activity of NaOCl solution of 2.5mg AC/L increased with decreasing pHs from 9.3 to 5.7. The logarithmic relative reductions of viable P. fluorescens were proportional to the product of the AC concentration and time, and the rate of inactivation depended on the concentration of undissociated hypochlorous acid (HOCl). Our results show that the cleaning and bactericidal activities of NaOCl solution are governed by the percentage of HOCl and -OCl existing in the solution.