Evaluation of the Antimicrobial Effectiveness of Ozonated Water for Hand Washing in the Presence of Organic Material Contamination Using the ASTM E2946-13 Standard Test Method

Abstract

Ozonated water is a possible handwashing alternative to antimicrobial soap and water. In a previous report, 4 ppm of ozonated water removed artificially contaminated bacteria from the hands of healthy volunteers as effectively as antimicrobial or non-antimicrobial soap and water. Currently, there is a lack of data on the efficacy of ozonated water in removing bacteria from hands loaded with organic materials. This study aimed to evaluate the effectiveness of ozonated water in removing bacteria from hands contaminated with organic material, according to the American Society for Testing and Materials E2946-13. Sixteen healthy volunteers were randomly assigned to the ozonated water group and antimicrobial soap and water group. Their hands were contaminated with an avirulent strain of Escherichia coli in beef broth suspension. Approximately three log10 CFU bacterial reductions between baseline and post-wash colonies were observed on the hands in both groups. Ozonated water may remove bacteria from hands contaminated with organic material with similar effectiveness as antimicrobial soap and water.