Application of gaseous ozone and its aqueous solution for inactivation of pathogenic microorganisms: A literature review

Abstract

Due to its potent oxidising properties, ozone presents itself as a promising disinfectant and may serve as a substitute for conventional techniques. The purpose of this study was to analyse the literature on the effectiveness of gaseous ozone and its aqueous solution against pathogenic and opportunistic microorganisms or their surrogates. More than 150 English-language sources have been studied, of which 72 have been selected for this review. To illustrate the effectiveness of ozone against bacteria, bacterial biofilms and viruses, data from selected publications are summarised in tables for the respective groups of disinfectant targets. In cases where data were presented in the form of kinetic curves in the reviewed publications, the maximum inactivation values were chosen. It was shown that both gaseous ozone and its aqueous solution are widely used due to their powerful bactericidal properties. The study noted that ozone is an effective oxidant that neutralises gram-negative, gram-positive, and spore-forming microorganisms, the biofilms they form, as well as fungi, protozoa, viruses, and prions. Among the industries that have implemented or may implement ozone applications are medicine (including dentistry and pharmacy), as well as the food industry and recreation. One of the notable advantages of using ozone is its relatively short half-life, with conversion to non-toxic oxygen. It was also noted that ozone treatment is non-thermal, which allows it to be used for processing fresh fruit and vegetables. The main disadvantages and challenges for safe implementation are ozone toxicity at exceeding the maximum permissible concentration in the air, corrosiveness, and explosiveness at high concentrations