Disinfecting Efficacy of an Ozonated Water Spray Chamber: Scientific Evidence of the Total and Partial Biocidal Effect on Personal Protective Equipment and in Vitro Analysis of a Viral Experimental Model

ABSTRACT

Due to the high recurrence of microbial infections, developing new technologies for preventing the dissemination of pathogens is essential, especially to prevent infection in humans. Thus, devices for the decontamination of surfaces reduce not only the spread of pathogens in the environment, but provide greater security and protection for communities. Ozone (O₃) is a substance capable of reducing or eliminating several types of microorganisms owing to its biocidal capacity, including when it is dissolved in water. The objective of this study was to develop an instant decontamination device using ozonated water. To confirm its biocidal action and verify the device’s efficacy, the reduction of the microbial load of important pathogens on personal protective equipment (PPE) was assessed. In addition, in order to confirm the biocidal action of ozonated water against SARS-CoV-2, in vitro tests on a viral model of Gammacoronavirus were performed. The results showed the efficacy of ozonated water in the disinfection device at concentration ranges of 0.3–0.6 mg/L and 0.7–0.9 mg/L of ozonated water, with growth reductions above 2 log₁₀ for both concentration ranges tested and inactivation fractions above 60% (0.3–0.6 mg/L) and 80% (0.7–0.9 mg/L), with a high proportion of the tested PPE showing 100% microbial reduction. In vitro results for the evaluation of ozonated water in a viral model showed a 99.9% reduction percentage in the concentration range of 0.3 to 0.5 mg/L and a 99% reduction in the concentration range of 0.6 to 0.8 mg/L, with a 5.10 log EDI50/mL and 6.95 log EDI50/mL reduction, respectively. The instant decontamination system developed in this study proved effective for microbial reduction, and we confirmed the potential of ozonated water as a biocidal agent. Therefore, the proposed decontamination device could be considered as a tool for reducing contamination on surfaces using ozonated water.

KEYWORDS:

• Ozone
• aqueous ozone
• antimicrobial
• disinfection device
• ozonation unit
• SARS-CoV-2

Acknowledgments

The authors would like to thank the University Center SENAI/CIMATEC (National Service for Industrial Training, Serviço Nacional de Aprendizagem Industrial), SENAI CIMATEC (Bahia, Brazil), and China Three Gorges Corporation, CTG Brazil (Rio Paraná Energia S.A), for the resources for the ANEEL R&D Program (PD-10381-0420/2020).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data resulting from this research are available in this manuscript.

Additional information

Funding

This research was funded by China Three Gorges Corporation–CTG BRASIL (Rio Paraná Energia S.A. Rodovia MS-444 s/n° km 58, Ilha Solteira, Selviria 79590-000, MS), with resources for the ANEEL R&D Program (Agência Nacional de Energia Elétrica / PD-10381-0420/2020) and SENAI CIMATEC (Serviço Nacional de Aprendizagem Industrial - Campus Integrado de Manufatura e Tecnologia).