Letter to the Editor about "Eradication of Bacillus licheniformis Contamination while Maintaining Employee Safety in a Gnotobiotic Mouse Colony"~Roger P. Orcutt
{Exspor & Clidox CD} "Chorine dioxide is not only a potent sporicide when used in aqueous solution, but has also been shown to be 1,075 times more sporicidal than ethylene oxide gas when used in the gaseous state1, a trait Dr. Trexler considers essential for any sporicide used in Gnotobiotics because air bubbles can become trapped below liquids" "0.007%. The stoichiometry of the reaction of the Clidox-S® base (sodium chlorite) with the Clidox-S® activator (hydroacetic acid) shows that even if every single molecule of the 0.85% sodium chlorite in the Clidox-S® base were converted completely to chlorine dioxide, it would still not generate the 3% (30,000 ppm) of chlorine dioxide cited." "the role of biological burden should have been given more consideration. What is the probability that a million spores would fall from the ambient air into an entry port during the brief time it is open? With an exposure time of mere minutes, one would undoubtedly be challenged with no more than 10 to a 40 viable dust particles and about 1 to 4 of them would be sporeforming species"
Methods for treating an object with chlorine dioxide - Google Patents, published 2016
****!!!!****!!!!**** {ICA TriNova} "method for treating an object with chlorine dioxide gas, comprising contacting the object with chlorine dioxide gas while exposing the object to less than 1000 lux of light. The disclosed method minimizes chlorine containing residue on the surface of the object. The object can be a raw agricultural commodity (RAC) such as a raw fruit or vegetable." "Residues on the walls of each jar were quantitatively recovered by washing the walls sequentially with 4-50 mL aliquots of nanopure water and combining the aliquots with additional water to bring the total volume to 250 mL. These washings were analyzed by ion chromatography for chlorate and perchlorate ions. Based on reaction profiling of these particle mixtures, the weights of the particles provided within the TYVEK sachets were adjusted so that, upon reacting, a total of 1.6 mg of ClO2 would have been produced in each jar during the 2 hour period. " "Gas Chamber Studies Show Chlorate and Perchlorate Ions can be Minimized and in the Case of Perchlorate Eliminated when Fumigation is Performed in the Substantial Absence of Light when RACs are Present" "At 120 minutes, chlorine dioxide concentrations... fell well below expected concentrations, likely due to system leaks or to chlorine dioxide reacting with the exposure chambers themselves or with the silicone sealant used on the tanks. When tomatoes were present in the treatment chambers, chlorine dioxide gas was measurable only through 30 minutes for two replicates and through 60 minutes for one replicate. These data clearly indicate that tomatoes acted as a chlorine dioxide sink, consistent with studies using radiolabel showing the propensity for chlorine dioxide consumption by biologic materials, especially those tissues with a porous surface"
Chlorine Dioxide Reactions with Indoor Materials during Building Disinfection: Surface Uptake
****!!!!**** The focus of this paper is on chlorine dioxide removal from air to each of 24 different indoor materials... Deposition velocities and reaction probabilities varied over approximately 2 orders of magnitude across all materials. For most materials, deposition velocity decreased significantly over a 16-h disinfection period; that is, materials became smaller sinks for chlorine dioxide with time. Four materials (office partition, ceiling tile, medium density fiberboard, and gypsum wallboard) accounted for the most short- and long-term consumption of chlorine dioxide. Deposition velocity was observed to be a strong function of chlorine dioxide inlet concentration, suggesting the potential importance of chemical reactions on or within test materials."
Remediation of Soil Contaminated with Bacillus anthracis spores ~EPA
****!!!!****!!!!**** " Nearly all AZTD samples completely decontaminated • Greater than 6 LR for topsoil at 1 cm depth, 2 hour, both RH levels • 2 cm topsoil much more difficult to decon" "Aqueous ClO2 completely ineffective ( 0.5 LR) at
most robust test conditions (4000 ppm, 2 hr contact Time, 4 spray applications)"
Portable Decontamination and Sterilization System--slide presentation
****!!!! "Adding salt to the aqueous solution used to produce sterilant allows humidity control, which improves kill of bacterial spores" "• Indicator to show ClO2 is present: • Indicator is printed on or attached to inside of pouch • Changes color on exposure to ClO2" "Reversible indicator on outside of sterilizer bag to show when unit is too cold and should be warmed for correct functioning" "To eliminate bacterial spores, it is highly desirable to control the humidity during sterilization to 70 to 95%, preferably 90 to 95%. Adding NaCl to the NaClO2 solution lowers the humidity of the gases produced from 100% to the desired range."
Wet scrubber analysis of volatile organic compound removal in the rendering industry - PubMed
The promulgation of odor control rules, increasing public concerns, and... (EPA) air regulations in nonattainment zones necessitates the remediation of a wide range of volatile organic compounds (VOCs) generated by the rendering industry." "wet scrubber analysis using chlorine dioxide (ClO2) as the oxidizing agent indicated that close to 100% of the methanethiol was removed from the gas phase, but removal efficiencies ranged from 20 to 80% for the aldehydes and hydrocarbons and from 23 to 64% for total VOCs"
A radical approach to methane oxidation into methanol: Researchers convert methane to valuable chemicals using clean, low-temperature radical reaction
****!!!! (2017) "This is the first aerobic oxidation of methane without using high temperature/pressure, and the concept could allow industry-scale reactions with reduced environmental impact." "This doesn't occur in water, but unfortunately methane barely dissolves in water." The researchers found a neat way around this: two solvents in a single system, one for each step of the process. The initial ClO2• formation occurs in a water phase, where sodium chlorite is soluble. Then, ClO2• transfers to a perfluorohexane (PFH) phase, where methane and O2 dissolve to react with them.
"PFH is ideal for the second step: it dissolves methane, but doesn't react with CH3• radicals," explains Ohkubo. "This creates a space for the oxidation of CH3•, giving the desired products. Then, after methanol and formic acid are formed, they cross the solvent boundary in the opposite direction, into the water phase. Here they are protected against further oxidation into unwanted CO or CO2 as greenhouse gasses."
The complete process is impressively efficient, converting over 99% of methane into the target products, without the need for high temperature or pressure.
"This is the first successful use of oxygen in the air to oxidize methane under ambient conditions,"
Light‐Driven C−H Oxygenation of Methane into Methanol and Formic Acid by Molecular Oxygen Using a Perfluorinated Solvent
"Oxidation of hydrocarbons: The chlorine dioxide radical (ClO2.) was found to act as an efficient oxidizing agent in the aerobic oxygenation of methane to methanol and formic acid under photoirradiati...
Comparison of Chlorine Dioxide and Ozone as Oxidants for the Degradation of Volatile Organic Compounds
"The results show that dimethyl trisulfide and isoprene were substantially degraded
into other by-products, including methane sulfonyl chloride and sulfur dioxide, during
oxidation by chlorine dioxide and ozone, respectively. In contrast, 1-bromopropane, 2,3-butanedione and 1,1,2-trichloroethane have slow reaction kinetics and did not break down completely. Degradation of dimethyl trisulfide by chlorine dioxide and ozone follows the second order kinetics with half-lives of 2.2 min and 24 min, respectively. On the other hand, isoprene follows the first order reaction kinetics with rate constants of 0.4051 min-1 and 0.02244 min-1 and half-lives of 1.73 min and 32 min for degradation using ozone and chlorine dioxide, respectively. iv The oxidative degradation of 1-bromopropane, dimethyl trisulfide, and 2,3-butanedione by chlorine dioxide were more efficient than their reactions with ozone. However, the degradation of isoprene and 1,1,2-trichloroethane showed a greater reactivity toward ozone compared to chlorine dioxide. Most of the reaction products of oxidative degradation such as acetone, ethanol, formic acid, and dimethyl ether are chemically benign. But there are also by-products such as methane sulfonyl chloride, sulfur dioxide, chloroform, and cyanogen bromide that require further toxicological study."
'New' Chlorine Dioxide Method Adapted to Control VOCs
"Tiberian Technologies' Process & Equipment Division in March 1999 undertook pilot studies to model the performance of the patented SVP-Pure chlorine dioxide scrubber technology" "Eka's process generates chlorine dioxide gas from a mixture of sodium chlorate, hydrogen peroxide, and sulfuric acid. The process is rapid and better than 95% efficient" " using the SVP-Pure process versus the compliance test results (using the previous chlorite-based process) produced an average reduction of 52% in VOC emissions." "the sodium chlorate and hydrogen peroxide are available pre-blended as Purate to minimize the bulk storage needs"
****!!!! When a water tap is opened, small amounts of chlorine dioxide diffuse into the air and combine with existing household odors. All homes have volatile organic compounds (VOCs) in the ambient air produced by scented products (soaps, candles, air fresheners, incense, potpourri), cleaning agents or solvents, paint, carpet, furnishings, fresh flowers or wreaths, and many other common household items. The VOC/chlorine dioxide combination odors have been described as smelling like fuel oil, kerosene, chemicals or cat urine, to name the most common. Studies have not identified any health concerns associated with this combined odor. The strongest odors are associated with installing new carpet, upholstered furniture or draperies andinterior painting. The odor will continue until the level of VOCs decreases (new smell goes away). This can take from a few weeks up to several months to dissipate depending on the situation, type of materials, amount of ventilation, etc.
The Role of Water Solubility and Diffusion Coefficient in Air of Chlorine Dioxide Gas during Surface Decontamination and Compatibility of Selected Plastics and Elastomers
****!!!!****!!!!**** {Includes data table of studies of gas and liquid against specific pathogens on food} "ClO2 disinfects by oxidation through the one-electron transfer mechanism, resulting in a reduction to ClO2–...The inactivation may be reached by allowing permeability of the cell membrane by changing the configuration of lipids and protein which involve the oxidation of amino acids by the gas. The second option is due to the reaction with nucleic acid and/or protein structures... However, some research showed degradation in viral RNA, inducing genotoxicity or discontinuing replication of genome information." "At higher relative humidity, a greater reduction of pathogen population was reported. This might be explained due to the increment of the pores’ sizes in the bacteria due to swelling at high humidity, which allow penetration of the ClO2 molecule into the bacteria." "Gaseous ClO2 showed a negative
impact on treated fruits and vegetables through enzymatic browning formation... is related
to the deterioration of nutritional quality. However, additional treatments can be added to the gas exposure to inhibit browning..." "negative color change in spinach leaves, which occurred during storage after being exposed even to 50 ppm of gaseous ClO2. Also, treatments with higher concentrations may lead to bleaching of fruits and vegetables" "reaction rate was estimated to be... which is significantly higher than the reaction rate reported by previous researchers ... the chamber used here was stainless steel... likely increased the reaction with the walls, and created minor corrosion" "larger exposure surface area for the water in contact with the gas increased the overall decay rate" "some crevices in equipment could
impact the effectiveness of the ClO2 gas treatment due to the time for gas to diffuse into the crevice" "the ClO2 gas concentration is surface area- and water volume-dependent" "Results showed an increase in the reaction rate due to water presence at different water volume and exposure surface area. After 7 days’ exposure at 3000 ppm of ClO2 gas, none of the selected plastics or elastomers showed a significance difference (p0.05) in the hardness value." "excitation wavelengths of ClO2 are near the ultraviolet and visible light... leads to dissociation into ClO + O or Cl + O2" " Further
research can also be extended to determine the rate of ClO2 molecules dissolving into water, and the residuals form."
****!!!!**** (2019) {Instructions (some of which probably need changes/corrections) for many uses. Also, lists of pathogens affected, with linked studies.} Vapor for Disinfection & Mold Elimination: 1 Gram Chlorine Dioxide per 1 square feet (w/10’ ceilings) [Researcher calcs: (0.28 m3). =3,571 mg/m3=1,275 ppmV in air], 3 to 24 hours – depending on issue severity of issue *****Concentrations to use for many applications****chart below shows how well ClO2 performs against alternatives. (other disinfectants)** Pathogens lisr with studies references **RECOMMENDED SPECIFICATIONS FOR CONTAINERS USED WITH CLO2 PRODUCTS...wear a NOISH/MSHA-approved respirator under the following conditions..." "Initial or remedial treatment... DECORATIVE AND ORNAMENTAL FOUNTAINS... Achieve a 5 ppm solution RESIDUAL concentration" "Continuous treatment... between 0.25 ppm and 0.5ppm"
THE BACTERICIDAL ACTION OF PROPYLENE GLYCOL VAPOR ON MICROORGANISMS SUSPENDED IN AIR : II. THE INFLUENCE OF VARIOUS FACTORS ON THE ACTIVITY OF THE VAPOR
****!!!!**** (1943) {Note: Air sanitizers using glycol can be easily registered with EPA using basic data. Other substances require more data submission.} "The killing process was found to be more effective when both the total number of air-borne droplets and the number of organisms in the bacterial suspension are small. A temperature below 80°F. and an atmospheric relative humidity between 45 and 70 per cent were found to constitute the most favorable conditions for the lethal action of the vapor. Experiments were performed to test the bactericidal efficiency of propylene glycol vapor in both small and large enclosed spaces. These studies revealed that equally marked bactericidal action is obtained when propylene glycol is dispersed in an 800 cubic foot room as occurs in chambers of 2 cubic foot capacity. The susceptibility to vapor action of bacteria re-suspended in saliva was just as great as when broth was used as the suspending medium. Both partially and completely dehydrated bacteria also succumbed to the effects of the vapor. However, when unsterile dust collected from inhabited rooms was dispersed into the air, little reduction of the natural microbic population contained in this material was observed."
Effect of chlorine dioxide on avian influenza A (H7N9) virus
****!!!!****!!!!***** "An aqueous solution of ClO2 at 126 ppm (w/w) for 15 s was effective, and no surviving virus was detected with the hemagglutination test. ClO2 gas at 5 ppm (v/v) sustained for 1 h inactivated the virus effectively, while at 2.5 ppm for 1 h only partially inactivated the virus."
INTERNATIONAL DECONTAMINATION RESEARCH AND DEVELOPMENT CONFERENCE, Nov 2021 ~EPA
****!!!!****!!!!****!!!! "Novel Technology to Reduce Risk of Viral Transmission in Enclosed Occupied Environments and Room Disinfection in Unoccupied Spaces, METSS Corporation: ... development of a novel chlorine dioxide (ClO2) gas dispersion system under a current EPA-sponsored Phase II SBIR project...). The system design offers a safe and effective means to rapidly generate ClO2 vapor for on-site room decontamination in hospital and non-hospital settings. This technology is intended to meet the demands of health care markets committed
to decontaminate porous materials and sensitive equipment in rooms or vehicles used for care or transport of Ebola-exposed patients... current COVID-19 pandemic has demonstrated a clear need for technologies aimed at occupied spaces to reduce or prevent the spread of transmissible diseases through air or contact with surfaces contaminated with infectious microdroplets." "y. During repeated trials, METSS demonstrated the efficacy of low level ClO2 against Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae. Additional efficacy testing was performed using MS2 (non-enveloped) and Phi6 bacteriophage (enveloped) as surrogates to SARS-CoV-2 and other human viruses...." "Decontamination of Covid-19 Vaccine Production Facility: ...a study completed within the United States Pharmaceutical Industry alongside ClorDiSys Solutions, Inc established evidence that chlorine dioxide gas has the capacity to inactivate beta-lactams" "t to achieve a 3-log reduction of beta-lactams, an inactivation cycle consisting of a 30-minute conditioning phase at 75% relative humidity, followed by an exposure to chlorine dioxide gas of at least 7,240 ppm-hours, is required. Chlorine dioxide destroys the beta-lactam ring and inactivates the compound, in similar fashion to the manner in which penicillin-resistant organisms act" "exposing the target beta-lactam to Chlorine dioxide gas at a concentration of 5mg/L"
"Outdoor Systems Trial Using Full-Scale Agricultural Equipment for Wide Area Decontamination of Bacillus anthracis Surrogate Spores": ...we exploited state-of-the-art spray application technologies and formulation chemistry used in the agricultural industry, spore germination techniques and a novel decontaminant based on the targeted release of chlorine dioxide. Spores of B. thuringiensis HD-1 cry- were employed as a surrogate for virulent B. anthracis. However, key performance attributes were validated against a range of virulent B. anthracis. Preferred formulations for decontamination were developed through laboratory, environmental chamber, windtunnel and finally full-scale outdoor trials. During outdoor trials we achieved all essential success criteria on all surface types (4-Log10 reduction on wood, steel and cement). Results using steel surfaces approached that required for desirable performance (6-Log10 reduction). Significant loss of spore viability was found by environmental exposure alone (up to 3-Log10 over 72 h). However, active decontamination was more effective (up to a further 3.6-Log10 reduction in viable spores). Pre-germination before decontamination with chlorine dioxide was not found to have a benefit."
"Use of Innovative Packaging to Facilitate On-Site Treatment of Waste from a Bacillus anthracis Release Incident: ...These semi-permeable materials would allow gaseous fumigants such as chlorine dioxide (ClO2) to pass into the bags but would not allow residual spores to penetrate the walls of the bags and exit into the atmosphere. Testing is currently occurring... to assess the ability of the materials to allow ClO2 to penetrate through the bag material and... to provide sufficient concentration-time exposure of the waste inside the permeation chamber"
study on the light degradation law of gas chlorine dioxide
****!!!!****!!!!*** (2011) "degradation rate of chlorine dioxide with the same initial mass concentration decreased gradually under uv, sunlight, 254 nm uv and 400-700 nm fluorescence, respectively, and the degradation rate of chlorine dioxide with the same initial mass concentration increased with the increase of gas mass concentration when the temperature varied from 15 to 25°c. therefore, the wavelength that plays a major role in the photodegradation of chlorine dioxide is ultraviolet light near 365 nm; the temperature has little effect on its degradation rate; under sunlight exposure, the degradation rate of chlorine dioxide is proportional to the first square of mass concentration, which belongs to the primary reaction, and its half-life is not related to the initial mass concentration, only related to the reaction rate constant k, and the half-life is about 63 min."
Reaction and diffusion of chlorine dioxide gas under dark and light conditions at different temperatures
****!!!!****!!!!*** (2015) ***"A methodology is proposed for quantifying the amount of ClO2 gas needed in a package and/or treatment chamber." "The diffusion coefficient was found to be 0.129, 0.145, 0.173 cm2 s−1 at 5, 23, and 40 °C, respectively. Degradation of ClO2 gas under dark, UV-A and fluorescent lamp exposure was found to follow a first-order reaction. Degradation using a 40 W UV-A lamp was approximately four orders of magnitude larger than with a 34 W fluorescent lamp." "ClO2 gas can also be converted to chlorite and then react with oxygen changing their chemical structure, mobility, and properties" "Normally, the antimicrobial activity of gaseous ClO2 increased with a longer treatment time, especially at a low treatment temperature"
****!!!!**** {Includes novel approach for using chlorine dioxide to spray area, as classified for stored potable water} "certified organic by OMRI and Kosher by OU." "Oxine may be used as a primary water disinfectant in municipal water at levels of 0.5 ppm and in stored potable water at levels of 5.0 ppm." "Bacterial, mold and odor control is easily restored by an initial application of activated Oxine, from 200 to 500 ppm, depending on the severity of the problem, sprayed onto the wall and floors. Follow this initial application with a periodical maintenance dosage of 100 ppm unactivated" "The filler head assemblies are considered food contact surfaces..." ***** "Low dose applications of Oxine, misted onto the filler assembly during short scheduled breaks in the production day, have proven to be of considerable benefit."
Method for extending storage period of chlorine dioxide deodorant and chlorine dioxide deodorant - Google Patents, JP2009050437A
"extending storage period and usable period of a deodorant as a product by preventing generation of chlorine dioxide gas in a sealed container, and also to provide a gel-type chlorine dioxide deodorant having a storage period extended by the method. SOLUTION: Generation of chlorine dioxide gas is prevented by using gellan gum as a gelling agent and by making the gel-type chlorine dioxide deodorant white. By doing so, shelf life of the deodorant as a product is extended, and a usable period of the deodorant is also extended."
Use of storage-stable aqueous solutions of chlorine dioxide to generate pure chlorine dioxide gas for decontamination - [CDG Environmental] Google Patents
****!!!!****!!!!**** "New compositions and methods are disclosed for decontaminating surfaces and enclosures that avoid problems such as salt deposits, corrosion and condensation that accompany the use of known methods. The process involves the use of chlorine dioxide solutions prepared by passing dilute chlorine gas over solid granular sodium chlorite to produce chlorine dioxide gas which is then collected in solution." "...mixing the gas with a carrier gas to produce a gas stream containing chlorine dioxide and disinfecting an enclosure. The gas can be produced by releasing chlorine dioxide gas from an aqueous chlorine dioxide solution containing less than 10% by weight of any of hydrochloric acid, hypochlorite ion, hypochlorous acid, or sodium chloride or it can be produced directly for use, as described above. When solutions are used it is preferred that they contain no more than 5%, or more preferably 2.5%, [etc] of... contaminants." "[Anthrax treatment:] As chlorine dioxide gas is stripped out of solution in this method, micro-droplets of solution became entrained in the resulting gas stream and were carried into the building. These droplets deposited a corrosive mixture of water and contaminants throughout the building space causing severe corrosion and other damage. Even where there was no corrosion, salt deposits had to be removed after decontamination was complete. In addition, the solution became hot as it was produced and when pumped into the stripper column (material transfer device) and contacted with air heated by the blowers, the gas stream was warm and humid. This resulted in severe condensation within the building when the warm, humid air contacted cooler air and cooler surfaces in the building. Large mechanical cooling units were used to partially dehumidify the air but a method was never found to control humidity and chlorine dioxide gas concentration simultaneously."
"At the heart of the GAS:SOLID™ chlorine dioxide generation process is the reaction between chlorine gas and SAF-T-CHLOR™ thermally stable solid sodium chlorite. This reaction produces no by-products—just pure chlorine dioxide gas (in air or nitrogen), free of chlorite ion, chlorate ion, perchlorate ion or molecular chlorine" "The CDG GAS:SOLID™ system uses SAF-T-CHLOR™ thermally stable solid sodium chlorite. SAF-T-CHLOR™ sodium chlorite is thermally stable, even on extreme localized heating (1,000° C) for a prolonged period (10 minutes). This is in stark contrast to conventional solid sodium chlorite: even on transient "
The application of high-concentration short-time chlorine dioxide treatment for selected specialty crops including Roma tomatoes (Lycopersicon esculentum), cantaloupes (Cucumis melo ssp. melo var. cantaloupensis) and strawberries (Fragaria×ananassa). - Abstract - Europe PMC
Europe PMC is an archive of life sciences journal literature.