## 1 Introduction
Previous studies demonstrated the benefits of using ultraviolet-light devices for disinfecting hospital environments [16], portable devices with spraying systems for the decontamination of surfaces [17], and disinfection chambers with different biocidal agents [18; 19], which drew attention with the SARS-CoV-2 pandemic. The development, advertising, and marketing of tunnels or cabins, or disinfection chambers have spread in several countries, although there is still no scientific evidence to support them [20]. City halls have installed this kind of system in several places, such as streets areas with heavy pedestrian traffic, highways, industries, malls, and offices [20]. It is usually set up at the entrances of, or inside, public transports [21; 22]. These devices make use of substances such as sodium hypochlorite, ozonized water, ozone, or other biocidal agents [23]. In Brazil, this equipment was developed to meet the demand of institutions interested in disinfecting employees at workplace entrances and exits. Regarding the regulation of this equipment, the National Health Surveillance Agency (Anvisa) and other regulatory agencies clarified that there is no evidence that this measure is effective against the coronavirus pandemic [21; 23]. The choice of chemical agent to be applied to these technologies is of paramount importance, and should be based on the recommendations of their manufacturers and on reports of agencies that alert and control the use of these substances in order to avoid safety and toxicity problems [24]. Among the list of sanitizers, one of the most promising biocide agents is ozone gas (O\({}_{3(\text{g})}\)). It consists of a natural configuration of three oxygen atoms, and it has a half-life of about 1 h at room temperature, with subsequent degradation and the spontaneous formation of oxygen gas [25]. It is naturally produced by sunlight, involving nitrogen oxides and volatile organic compounds [26], and can also be produced from electricity generators [27]. O\({}_{3}\) has unique biological properties, acting as a powerful oxidizer against viruses, bacteria, and protozoa; at recommended levels, it can be used as a microbicide gas and be dispersed in water [28]. O\({}_{3}\) leads to microbiological destruction through metabolic interferences. However, viral susceptibility might fluctuate in its presence. For example, for enveloped viruses, such as coronavirus, O\({}_{3}\) effectiveness may be more accentuated than that on nonenveloped viruses due to the O\({}_{3}\) interaction with the envelopes of the lipid layer [28]. There are few studies that report the action of O\({}_{3}\) on SARS-CoV-2 [29]. However, some authors reported O\({}_{3}\) disinfection in the influenza A virus, respiratory syncytial virus [30], and SARS-CoV-1 [31], which can serve as reasonable substitutes in studies of O\({}_{3}\) disinfection against SARS-CoV-2. O\({}_{3}\) action is also proving effective against other types of microorganisms, expanding the possibilities of using this gas as a microbicide agent. Nonetheless, O\({}_{3}\) can be toxic in gaseous form; when dissolved in water, its degree of toxicity is reduced, and the sanitizing effect is maintained [32; 33; 34; 35]. In addition, O\({}_{3}\) dissolved in water (or ozonized water (O\({}_{3(\text{aq})}\))) already has wide application in the treatment of dental diseases [36], and its use has been growing in other areas. Therefore, this substance can be a better alternative as a biocide solution in disinfection chambers. In fact, O\({}_{3(\text{aq})}\) has several advantages, being effective in reducing several pathogenic microorganisms, including not only viruses, but also bacteria and fungi [34; 35; 37]. In this sense, the use of O\({}_{3(\text{aq})}\), associated with disinfection-chamber technology enables a range of uses both in the current pandemic and in other contexts where infectious diseases may spread. Several disinfection chambers are being produced and commercialized with the purpose of being used by humans as a protective barrier.