2003. Appendix B: "CT VALUES* FOR 4-LOG INACTIVATION OF VIRUSES BY CHLORINE DIOXIDE pH 6-9" "CT VALUES* FOR 3-LOG INACTIVATION OF GIARDIA CYSTS BY CHLORINE DIOXIDE"

(2001) "The efficacy of chlorine dioxide as a water disinfectant is sufficiently well characterized that EPA has developed a set of tables predicting the degree of inactivation of microorganisms as a function of the concentration of disinfectant, the time of contact, temperature, and acidity of the water to be treated [Note: EPA document says that data sources used were quite limited, however.]"

{Includes chart of critical levels for pathogens in water} "Shock treatment is recommended twice a year and usually requires a concentration of 20-50ppm chlorine dioxide be maintained for 12 hours, and then the irrigation system thoroughly rinsed before irrigation begins again, due to risk of phytotoxic effects with high concentrations. After shock treatment, a continuous treatment of 0.25ppm residual chlorine dioxide is usually sufficient to prevent regrowth of biofilm. " "The optimum chlorine dioxide range to treat biofilms and common plant pathogens is 0.25 to 3.3 ppm"

*****!!!!**** {Data on effectiveness of various disinfectants. Also data on survival of SARS-CoV-2 on various surfaces}

****!!!!**** {Direct testing against SARS-CoV-2} "To better inform the choice and use of disinfectants by DHS operators against SARS-CoV-2, the NBACC performed studies to evaluate the effectiveness of several products to reduce SARS-CoV-2 contamination when it was in simulated respiratory fluids. Disinfectants were tested against both wet and dried virus droplets to simulate disinfection of fresh and old contamination. No pre-cleaning or wiping was done during these tests to model a high tempo operations scenario where disinfectant is simply applied onto a potentially contaminated surface without precleaning or wiping"

****!!!!!*** {Chart of various disinfectants, hand sanitizers, etc directly against SARS-CoV-2}

****!!!!!****!!!!*** {Includes chart of Chlorine Dioxide vs Sodium Hypochlorite effectiveness against many pathogens}

2020. {Testing of various formulations on various organisms} "average concentration of chlorine dioxide in the high and low test groups was 224.1 mg/L and 75.2 mg/L, respectively. There was no significant difference between the average concentration of the high and low concentration groups and their theoretical concentrations, and the results of the chlorine dioxide content determinations were consistent with their theoretical concentrations. The average of the 5 measurement concentrations of the combined sodium chlorate powder dissolver in the control group was in the theoretical concentration (380 to 460 mg/L). Therefore, the improved five-step iodine measurement results are accurate, and the method can be used as an effective detection method for chlorine dioxide disinfectant products. The results of the qualitative quantitative killing test of chlorine dioxide solution on four bacteria showed that when the effective concentration of chlorine dioxide solution was 3.12 mg/L, it had a 1 min effect on E. coli 8099, and the kill rate was 99.90 %, 10 min for Staphylococcus aureus ATCC6538, the killing rate reached 99.97 percent, the effect on type B hemolytic streptococcus 32210 30 min, the killing rate reached 100%; The effective concentration was 12.5 mg/L, which was 10 min for bacillus 63501, and the kill rate was 100%. Chlorine dioxide solution sterilization effect is good, and with the compound sodium chlorate powder sterilization effect is similar, and the sterilization effect is much better than ammonium methyl bromide solution. The results of the killing test of chlorine dioxide solution on swine fever virus showed that chlorine dioxide solution and compound sodium chlorate powder dissolver with concentration of 25 mg/L were able to achieve 100% inactivation rate when the Thiveral strain of swine fever virus was 3 min, indicating that the chlorine dioxide solution had good effect on swine plague virus eradication and similar effect to the pig plague virus."

****!!!!!*** 2020. "The potential role of ClO2 in completely inactivating porcine reproductive and respiratory syndrome virus (PRRSV) was demonstrated through the action of degrading the genome and proteins of the virus [4]. This study also confrmed that the expression of inflammatory cytokines induced by this virus can be reduced by ClO2. This is further supported bystudies reporting protein-denaturing activities due to covalent oxidative modifcation of cysteine, tryptophan and tyrosine residues of model proteins (bovine serum albumin and G6PD of Saccharomyces cerevisiae) as the mechanism behind the efficacy of ClO2 against microbes [13,14]. Furthermore, 0.03 ppm of ClO2 has been indicated to prevent aerosol-induced infuenza A virus by denaturing the envelope proteins of the virus [12]. The mechanism of norovirus inactivation by ClO2 is attained through degradation of viral protein, including viral genomic RNA and disruption of viral strucutre [15]. In addition, an observation on ClO2-reduced lysozyme activities showed the potential role of ClO2 in denaturation and degradation of protein "

"However, when chlorine dioxide generated by a gas generator typified by such a device is absorbed into water and used as a solution, it is unstable and cannot be decomposed in a short time to be useful for practical use. Here, chlorine dioxide generated in recent years is absorbed into an aqueous alkali solution (for example, an aqueous sodium percarbonate solution) and stabilized."

{Excellent chart of industrial uses} {Info on regulations for chlorine dioxide} "OxyChem technical sodium chlorite products"

****** "The most common method of generating ClO2 is through the reaction of chlorine gas with a solution of sodium chlorite. Theoretically, 1 lb of chlorine gas is required for each 2.6 lb of sodium chlorite. However, an excess of chlorine is often used to lower the pH to the required minimum of 3.5 and to drive the reaction to completion. Sodium hypochlorite can be used in place of the gaseous chlorine to generate chlorine dioxide. This process requires the addition of sulfuric or hydrochloric acid for pH control. Other methods used for chlorine dioxide generation include:..." "Complex organic molecules and ammonia are traditional chlorine-demand materials that do not react with chlorine dioxide. " "The chemical behavior and oxidation characteristics of aqueous chlorine dioxide are not well understood because of the difficulty in differentiating aqueous chlorine-containing species." "Chlorine dioxide consumed in water treatment reactions reverts to chlorite ions (ClO2-), chlorate ions (ClO3- ), and chloride ions (Cl -)." "As a gas, chlorine dioxide is more irritating and toxic than chlorine. Chlorine dioxide in air is detectable by odor at 14-17 ppm, irritating at 45 ppm, fatal in 44 min at 150 ppm, and rapidly fatal at 350 ppm. Concentrations greater than 14% in air can sustain a decomposition wave set off by an electric spark. The most common precursor for on-site generation of chlorine dioxide is also a hazardous material: liquid sodium chlorite. If allowed to dry, this powerful oxidizing agent forms a powdered residue that can ignite or explode if contacted by oxidizable materials. The hazardous nature of chlorine dioxide vapor and its precursor, and the volatility of aqueous solutions of chlorine dioxide, require caution in the design and operation of solution and feeding equipment."

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****!!!!****** {Includes equations for predicting impact of variables in determining quantity of byproducts} "At 20oC, pH 7, 70-80% of chlorine dioxideinjected was converted to chlorite and 0-10% of that was transformed into chlorate within 120 min with 2.91 mg/Lof DOC. The amount of chlorite formed also increased when pH and temperature increased. As DOC content increased,the residual chlorine dioxide decreased but the amount of chlorite and chlorate were increased. These experimentsrevealed that chlorate was a dominant by-product under UV irradiation."

****!!!!****!!!! {Materials suitable for Chlorine Dioxide containers} "Construction should be of dark or opaque/UV-blocking (preferred) oxidation-resistant plastic or glass. Some materials recommended include: -High Density Polyethylene (HDPE)- Polypropylene (PP)- Polyethylene Terephthalate (PET) (PETE)- Polyvinyl Chloride (PVC)- Polycarbonate (PC)- Glass (UV-blocking preferred)- Gasket materials; silicone, viton or EPDM" "DECORATIVE AND ORNAMENTAL FOUNTAINS 5 ppm residual chlorine dioxide level. Circulate water in normal operation of the system.... Repeat daily until desired results are achieved." "Selective Micro® Chlorine Dioxide Test Strips"

**** {Mix with dry citric acid, or 33% phosphoric acid} "Alternatives to citric acid for activation include organic acids, such as acetic acid, and inorganic acids such as phosphoric, hydrochloric, and sulfuric acids. Activation equivalent to that of citric acid may be achieved by adjusting the Pro Oxide solution to pH 2-3 with an alternative acid." "allow to dissolve for five minutes for citric acid or two minutes for phosphoric acid"

The mole ratio r(r=[I−]0/[ClO2]0) has great influence on ClO2-I−-H2SO4 closed reaction system. By changing the initiate concentration of potassium iodide, the curve of absorbance along with the reaction time was obtained at 350 nm and 297 nm for triiodide ion, and 460 nm for iodine. The changing point of the absorbance curve's shape locates at r=6.00. For the reaction of ClO2-I− in the absence of H2SO4, the curve of absorbance along with the reaction time can be obtained at 350 nm for triiodide ion, 460 nm for iodine. The mole ratio r is equal to 1.00 is the changing point of the curve's sh...

"Its efficacy is largely not affected by pH and organic matter and it does no react with nitrogen compounds to form chloramines. The most widely accepted antimicrobial mechanism of ClO2 is damage to protein synthesis and increased permeability of the outer cell membrane. ClO2 gas may be more effective for inactivation of foodborne pathogens than aqueous ClO2 due to its penetration ability. Also, ClO2 gas could be applied for microbial control during transportation and storage of food." "The specific objectives of this study were, (ⅰ) to investigate the effect of relative humidity, surface characteristics of samples, and temperature on the antimicrobial efficacy of ClO2 gas... on produce and food contact surfaces, (ⅱ) evaluate the antimicrobial effects of the combination treatment of ClO2 gas with ultraviolet (UV) radiation, aerosolized sanitizer, and dry heat against foodborne pathogens on produce and seeds, (ⅲ) develop portable sustained release formulation of ClO2 gas for field application." "Combined treatment of ClO2 gas (10 ppmv) and aerosolized PAA (80 ppm) for 20 min caused 5.36, 5.06, and 4.06 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively."

2007. "Endoscopes are immersed in 0.35 per cent per-acetic acid or 1100 PPM chlorine dioxide (ClO2) for 5 minutes. "

{Significant info on Chlorine Dioxide use, particularly against anthrax} "1994 study by Roberts and Reymond wherein vitro tests on Mucor piriformis, Botrytis cinerea, Penicillium expansum, and Cryptosporiopsis perennans were conducted. Conidial suspensions of each pathogen were pipetted into test tubes containing ClO2 at concentrations of 1, 3, and 5 mg/l. Samples were drawn at 30 second intervals and the number of viable colony forming units/ml (CFU) was determined. The resultsof the tests are presented in Table 3.2-7."

"contacting the object with chlorine dioxide gas while exposing the object to less than 1000 lux of light"

2013 ***!!!!*** "Tailing occurs even at constant ClO2 concentrations. The chlorine dioxide solution’s disinfecting capacity, virus aggregation and the resistant subpopulation were ruled out as reasons for tailing. Instead,the cause for tailing is the deposition of an adduct onto the virus capsid over the course of the experiment, which protects the viruses. This adduct could easily be removed by washing, which restored the susceptibility of the viruses to ClO2." "Important shortcoming of ClO2, namely its self-limiting effect on virus disinfection. Important to take this effect into account in treatment application." "Working solution of 0.410.7 mg/L chlorine dioxide. To compensate for ClO2evaporation and consumption throughout the experiment,concentrated ClO2(16 mg/L) was added at a rate of 8e20mL/min by means of a peristaltic pump."

To control the waterborne transmission of enterovirus 71(EV71), which is associated with hand foot and mouth disease (HFMD), it is essential to know the inactivation effectiveness of disinfectants on EV71 in water. In this article, we present a comparative analysis of the effects on EV71 following exposure to chlorine dioxide (ClO2) under different doses, pH, and temperature conditions. We show that the EV71 exhibited strong resistance to ClO2 (more than the MS2 standard) and that Ct value ranges required for a 4-log reduction of EV71 in buffered, disinfectant demand-free water at pH 7.2 an...

****Chlorine dioxide was not very effective at decontaminating bare pine wood. Testing included DioxiGuard 400 ppm (manufacturer Frontier Pharm had indicated would be 190 ppm) chlorine dioxide, and SanDes 1500 ppm chlorine dioxide. Tested surfaces: industrial‐grade carpet, decorative laminate, galvanized metal ductwork, painted wallboard paper, painted cinder block, bare pine wood and glass.

{Lactic acid can be used in generating Chlorine Dioxide.} Germ-killing composition produced by contacting an acid material, preferably consisting of at least about 15% by weight of lactic acid, with sodium chlorite in aqueous media, the amount of acid being sufficient to *****lower the PH of the aqueous media to less than about 7." including particularly advantageous for use in ultrasonic cleaning devices." "Other authority holds that the ClO2 accelerates the metabolism of a bacterial cell to the detriment of cell growth. Yet other credible authority asserts that the chlorine ion in ClO2 goes through as many as 8 possible oxidation states in passing through a spore wall. As an algaecide, ClO2 destroys the chlorophyll, breaks down the cell until water is lost from the protoplasm, and thereafter completely destroys or oxidizes the cell "

The ASC production with the DAR procedure using the saturated reactants maximizes both the antimicrobial compound yields and bactericidal effects of the ASC solutions.

******* "Tristel chlorine dioxide has been tested by a United States Biosafety Category 3 laboratory. Results demonstrate Tristel chlorine dioxide completely inactivates SARS-CoV-2 in 30 seconds in the presence of soilingin accordance with EN 14476:2013+A2:2019, at a concentration of 20 parts per million (ppm)."

{**************Extensive list of Chlorine Dioxide specs, with links to excellent calculators******} Chlorine dioxide, gas weighs 9.99 kg/m³ (0.00577459 oz/in³), melting and boiling points, molecular formula and weight, molar volume, CAS RN, description

***!!!!*** {Includes table of pathogen effectiveness levels} "Chlorite is the major inorganic by-product of the reaction of chlorine dioxide in water. Usually, the amount of chlorite formed will be 40-60% of the amount of chlorine dioxide which has reacted. " "Chlorine dioxide systems: acid chlorite and electrochemical generators "Typical chlorite yield for an acid-chlorite generator varies between 65-68%. Overall conversion efficiency is much lower than this as much of the acid remains unreacted." "Chlorine Dioxide ClO2 will inactivate pathogenic micro-organisms at the same rate between pH 5 and 9. This makes it ideal for disinfection of potable water and process water where the pH is up around 8.0." "ClO2 is approximately 5 times more soluble than chlorine and 50 times more soluble than ozone." "Chlorine Dioxide Reaction with Inorganic Compounds--Ammonia Nitrogen... Iron... Manganese..." "Sulfur Compounds... Cyanide..." "Oil and Gas... frac water"

{ Fumigation against Bacillus anthracis} "Results from the 750 ppmv ClO2 fumigation suggest that 750 ppmv was more damaging to Category 4 materials than the 3000 ppmv ClO2 fumigation. Although both fumigation concentrations resulted in severe physical damage to the computers by promoting rusting and corrosion, only the computers exposed to 750 ppmv ClO2 experienced unrecoverable failures. It is not readily understood why the lower concentration (same RH) fumigation was more damaging; however, the same sample size and difference in computer batches cannot be ruled out as confounding parameters." "fumigation with ClO2 produced large amounts of dust inside the computers... an acrid smell (attributed to hydrogen chloride)... Vacuuming of the visible dust not only served to remove the majority of this probable health hazard and prevent the dust from being spread... also may have assisted in keeping all computers almost fully operational after an entire calendar year. "