Bactericidal effects of chlorine dioxide gas against E. coli and S. Typhimurium in vitro

Chlorine dioxide gas is a relatively new sanitizer in the food industry that has more accessibility than its aqueous form. Depending on the method by which ClO₂ gas is generated, there can be byproducts like chlorite and chlorate ions, which can decrease its disinfectant effect and purity. Recently, new technology that generates chlorine dioxide without using chlorine gas has been developed to remove those defects. This new electrochemical method generates gaseous chlorine dioxide from aqueous sodium chlorite (NaClO₂). The present study was conducted to evaluate the effects of ClO₂ gas generated by an electrochemical method against foodborne microorganisms. To accomplish this, ClO₂ gas at different concentrations (1, 5, 10 and 20 ppm) was applied to E. coli and S. Typhimurium for different exposure times (1, 5, 10, 15 and 20 min) under room temperature conditions at <40% relative humidity. The results revealed ClO₂ gas was highly effective for the inactivation of E. coli and S. Typhimurium and showed a reduction in populations of over 5 log CFU/ml under ambient conditions with low relative humidity (30-40%). In conclusion, ClO₂ gas treatment is highly applicable to control of foodborne pathogens.