2010. Up to 4 mg/L of chlorine dioxide gas (generated from gel and solution) was emitted into occupied areas of a dental office, including an operating room, for workday. Air conditioning unit with plasma filter and high-efficiency particulate filter were also tested. After office closing, areas were checked for levels of fallen airborne microbes. Patterns of decontamination effectiveness were evaluated.

****!!!!***!!!*** (2017) {Includes CD bond specs for liquid & gas phases.} ***Disinfection using such low-concentration ClO2 gas does not require evacuation of people, and could be used to disinfect room air in the simultaneous presence of people.*** It is demonstrated that chlorine dioxide (ClO2) gas of extremely low concentrations that have no toxic effect to animals has strong anti-microbial activity against infectious microbes, such as bacteria and viruses... The use of ClO2 gas at very low concentrations may open new avenue of disinfection systems of room air without requiring evacuation of people. This review presents the details of the disinfection system of ClO2 gas." "The use of 0.03 ppm ClO2 gas is also useful in prevention of mosquito-related infective diseases, such as malaria and dengue fever, given that this concentration of ClO2 gas has a repellent effect against mosquitoes" "rats exposed to 0.1 ppm ClO2 gas for 24 h/day and 7 days/week for a period of 6 months were completely healthy " "rate of killing increases along with the increase in relative humidity. "

ClO2 based products for cleaning and disinfection of surfaces and air though wetting/wiping surfaces, spraying, fogging, **humidifying**, ClO2 gas generation.

******!!!!!******** "Organic films are probably common on atmospheric aerosol particles and that they may occur under certain circumstances on fog droplets, cloud droplets, and snowflakes. If present, they will increase the lifetimes of aerosol particles, fog droplets, and cloud droplets, both by inhibiting water vapor evaporation and by reducing the efficiency with which these atmospheric components are scavenged. The presence of the films will not cause a significant reduction of solar radiation within the aqueous solution. It appears likely, however, that the transport of gaseous molecules into and out of the aqueous solution will be impeded by factors of several hundred or more when organic films are present. Since incorporated gas molecules provide much of the oxidizing potential of atmospheric water droplets, the organic films will play a major role in droplet chemistry by strongly inhibiting solution oxidation."

** Air concentrations for odor control. Restoration-chemicals.com (China?) {Solid chlorine dioxide for long-term use in HVAC ventilation. Air pump to expedite vapor treatments.}

*******Prehumidifying to 70-75% RH for 1 hour made B subtilis niger far more susceptible to Chlorine Dioxide, inactivating 10-6 spores in 5 mins without tailing with an estimated D value of 0.55 min.Using controlled humidity, gas concentration, and temperature at atmospheric pressure, standard biological indicators (BIs) and spore disks .

****2020. China. Therefore, the safe disinfection based on chlorine dioxide is eligible to become the core means of active disinfection and epidemic prevention system for schools and kindergartens.

*****!!!!****!!!!*** {Provides excellent definitions of ppm in air vs. liquid, etc} [Helpful note: Molecular weight of Chlorine Dioxide is 67.45] The unit of gas concentration is converted into another unit.

****!!!!!***** Using a methodology that can maintain low chlorine dioxide concentration in air even under high humidity, examined the effect of humidity on airborne influenza virus inactivation at a very low gas concentration. It was shown that chlorine dioxide at less than 0.02-0.03 ppm has an ability to inactivate airborne influenza virus under 50% and 70% RH conditions. However, from a viewpoint of infection control, these researchers believed it is a minor effect which is merely additional to the major effect by the humidity itself, when considering the actual load of viruses released from an influenza patient in a room space and still active after certain time. Low concentrations of chlorine dioxide also make much less difference under 30% relative humidity levels common in winter." Original paper https://www.semanticscholar.org/paper/Inactivation-of-Airborne-Influenza-Virus-Using-Low-Nishimura-Hayashi/3cc74aad740dc6e036e76a3e4fdaee02a159a309 https://pdfs.semanticscholar.org/3cc7/4aad740dc6e036e76a3e4fdaee02a159a309.pdf

******!!!!****!!!!****!!!*** 2012. {Note: Click "Download full text" and wait. Full text file will download to your computer} "More than half of the ClO2 gas decomposed indoors." Gaseous ClO2 is chemically dissociated by light with wavelengths between 350 nm and 475 nm. They reported that the dominant (96%) dissociation products were ClO and O (atomic oxygen). It is important to take into account whether these dissociation products are toxic to humans. Judging from the short lifetime of O (39 ns), the toxic effect of this chemical, if ever present, would be negligible... High air temperatures and light irradiation accelerated the decrease of ClO2 gas concentration; the latter had the greatest influence. A quicker decay of concentration and greater value of the reaction rate constant of ClO2 were found under irradiated conditions, especially when a UV lamp was used... ClO2 gas concentration was significantly reduced when an evaporative humidifier was employed due to adsorption and a chemical reaction between the gas and the filter in the humidifier. The results obtained from these experiments can be used to predict the indoor concentration of ClO2 gas" "it was concluded that indoor humidity does not affect the reaction of the ClO2 gas" "an aquarium... filled with 10 L(2.64 gal) water was set in the room" "indoor ClO2 gas levels were lower in the room where water was present because the gas dissolved in water" "Ogata and Shibata (2008) reported that ****!! ClO2 gas concentration in virus aerosols is theoretically 0.12 µM when the aerosols are in equilibrium with 0.03 ppm ClO2 gas !!****, based on their revealed Henry’s equilibrium gas constant k = 3.9 × 10−5 mol 1−1 Pa−1. The present experiment showed higher concentrations of ClO2 in the water"

2010. This study aims to monitor bioaerosol levels of a local campus of a student health center in Taiwan and then to perform disinfection by applying chlorine dioxide. First, air samples were taken and evaluated in the six areas of the center. The average background bioaerosol levels were 714 +/- 1706 CF …

***Mentions use of Chlorine Dioxide in Air in Occupied Areas to combat respiratory infections.

2017. ****!!!!**** Chlorine Dioxide in Air tested on rats, with no significant damage. Personal air disinfectant of chlorine dioxide (gel?) had high virucidal activity against influenza virus; when CD was used at low, low-toxic concentrations, the virus titer in the air samples was reduced by 90% at 1–3 min, by 97% at 3–5 min, and by 99% at 10–12 min. Device was effective at least 30 days. The inhalation toxicity of CD was investigated in the experiments using the rats that were kept in an atmosphere of CD for a certain time. Then the structure of the trachea and lungs examined; the degree of oxidative stress was estimated from the tissue level of malonic aldehyde and the changes in the gene expression of all classes of antioxidant enzymes (a total of 15). The structure of the tracheal and lung epithelium was ascertained to be completely preserved; there were no increases in apoptotic cell death in both tissues or in lipid peroxidation in lung tissue. The enhanced protection of tracheal and lung epithelial cells against the highly toxic reactive oxygen species generated in the tissues is associated with the activation of gene expression of antioxidant enzymes in the epithelium, which is observed within the first hours after action of CDFull text (partially translated) at https://medi.ru/info/13658/

{Also includes treatment by nebulized inhalation} Disclosed is a countermeasure against the infection with a floating virus, which is characterized by supplying a ***chlorine dioxide** gas to a space suspected of the presence of a floating virus to such an extent that the concentration of the chlorine dioxide gas in the space becomes a concentration at which an animal can survive but the floating virus is deactivated.

2009 patent publication date. When the chlorine dioxide concentration was 0.07 ppm, there was about 60% reduction (45/71) in the enzyme activity"

*******!!!******** {Abstract}

When measuring gases like carbon dioxide, oxygen, or methane, the term concentration is used to describe the amount of gas by volume in the air. The 2 most common units of measurement are parts-per

2007. Chlorine dioxide disinfectant (193 ppm) was capable of sterilizing medical disposal of 3.2 × 10 CFU/mL with disinfection efficiency higher than 99.9% in the physician out-patient department. Spraying 1 mL of 200 ppm chloride dioxide solution twice onto the surfaces of different objects using the hand-held sprayer, the comparison for average disinfection efficiencies of the samples was door knob (100%) = handset of telephone (100%) & chair cushion (90.3%) & floor (20.5%) in series. In addition, the background data of biological aerosols also revealed that the comparison of average space colony numbers was semi-closed out-patient area in the physician department (318 CFU/m) & semi-closed out-patient area in the surgical department (183 CFU/m) & open-space emergency ward (58 CFU/m) in series. After using ultrasonic aerosol and handheld sprayer ways to sprinkle the chlorine dioxide solution into hospital spaces for 30 minutes, disinfection efficiency approached 95.0 %. The disinfection efficiency of chlorine dioxide in gas or solution phase is notably affirmative and available for the infection control of hospital.

2016. Here, we demonstrate that chlorine dioxide (ClO2) gas at extremely low concentrations, which has no detrimental effects on human health, elicits a strong effect to inactivate bacteria and viruses and significantly reduces the number of viable airborne microbes in a hospital operating room. Air concentration levels were 0.01-0.03 ppm. In test chamber, ClO2 gas at 0.01 or 0.02 parts per million (ppm, volume/volume) was present, the numbers of surviving microbes in the air were markedly reduced after 120 min. In the operating room of a hospital, viable airborne bacteria collected over a 24-hour period in the presence or absence of 0.03 ppm ClO2 gas were found to be 10.9 ± 6.7 and 66.8 ± 31.2 colony-forming units/m3 (n = 9, p < 0.001), respectively.

2018

****!!!!****!!!!**** {Taiko} "Can be applied to any space that can be in a closed state or an open state... Can be supplied at a concentration at which the animal can survive but the suspended microorganisms are inactivated. Therefore, the present invention can be applied to a space where an animal exists. More specifically, the present invention can be applied to living spaces (eg, residences, offices), medical institutions (eg, hospital waiting rooms, examination rooms, treatment rooms, operating rooms, anterior rooms, hospital rooms), research institutions, disaster medical facilities (eg, disaster containers, tents), public facilities (eg, stations, airports, schools), vehicles... When the chlorine dioxide gas concentration in the space is set to 0.00001 ppm to 0.01 ppm, there is no problem even if chlorine dioxide gas is continuously supplied. When the chlorine dioxide gas concentration in the space is 0.01 ppm to 0.1 ppm, the time for supplying the chlorine dioxide gas into the space is preferably 10 minutes to 480 minutes, and 15 minutes to 90 minutes. More preferably, it is more preferably 15 minutes to 60 minutes. When the chlorine dioxide gas concentration in the space is 0.1 ppm to 0.3 ppm, the time for supplying the chlorine dioxide gas into the space is preferably 0.5 minutes to 480 minutes, preferably 1 minute to 60 minutes is more preferable, and 2 minutes to 15 minutes is even more preferable."

****!!!!****!!!!**** 2016. Here, we demonstrate that chlorine dioxide (ClO2) gas at extremely low concentrations, which has no detrimental effects on human health, elicits a strong effect to inactivate bacteria and viruses and significantly reduces the number of viable airborne microbes in a hospital operating room. In one set of experiments, a suspension of Staphylococcus aureus, bacteriophage MS2, and bacteriophage ΦX174 were released into an exposure chamber. When ClO2 gas at 0.01 or 0.02 parts per million (ppm, volume/volume) was present in the chamber, the numbers of surviving microbes in the air were markedly reduced after 120 min. The reductions were markedly greater than the natural reductions of the microbes in the chamber. In another experiment, the numbers of viable airborne bacteria in the operating room of a hospital collected over a 24-hour period in the presence or absence of 0.03 ppm ClO2 gas were found to be 10.9 ± 6.7 and 66.8 ± 31.2 colony-forming units/m3 (n = 9, p &lt; 0.001), respectively. Taken together, we conclude that ClO2 gas at extremely low concentrations (≤0.03 ppm) can reduce the number of viable microbes floating in the air in a room. These results strongly support the potential use of ClO2 gas at a non-toxic level to reduce infections caused by the inhalation of pathogenic microbes in nursing homes and medical facilities.

(2013). The cafeteria had a volume of 2375 m3. Thus, to satisfy the 8-hr TWA limit of 0.3 mg/m3, disinfection was performed using 250 mg/L ClO2 solution. In performing the disinfection process, the ClO2 solution was equally divided among six ultrasonic aerosol devices (i.e., less than 0.475 L per container)

(2010). Chlorine dioxide (ClO2) has a strong antiviral effect, and can disinfect the surface of object and the air in space. In recent study on interaction between ClO2 and protein, ClO2 oxidatively modified tyrosine and tryptophan residues, and the pro-tein was structurally denatured. Since hemagglutinin and neuraminidase of influenza virus A/H1N1 were inactivated by the reaction with ClO2, it is likely that denaturation of the proteins caused inactivation of the virus. A low concentration (0.03 ppm) of ClO2 gas, where people can stay for a long period of time without any harmful effect, prevented the death of mice (0 of 10 mice versus 7 of 10 in controls) caused by infection of influenza virus delivered as aerosol. We review current information based on the efficiency of ClO2 solution and gas, and also discuss the application of ClO2 against influenza pandemics outbreak.