Air CD Disinf--High Concentration

"CD was highly efficacious in reducing B. subtillis spores onpaper, plastic, epoxy-coated stainless steel, and wood surfaces(7). In addition, no corrosion was observed when using pharmaceutical-type materials such as 316 and 304 series stain-less steel, Lexan, and other commonly used plastics includingDelrin, Teflon, UHMWPE, Viton, and PVC (8). In a separatestudy, postexposure rinses of 304 stainless steel coupons inwater-for-injection showed no residual CD when measuredwith a high-pressure liquid chromatographic method for chlo-ride detection"

"Aeration time for this project was on average between 45 and 60 minutes, which matched the calculated and published aeration times. [18][19][20][21] CD gas is an oxidizer, but when it is produced with a dry gas and used as a gas, it is not corrosive as gases in solutions typically are. Solutions of CD gas are typically corrosive due to the acids and sodium chlorite involved."

methods utilized for the decontamination of Class II biological safety cabinets (BSCs).

Chlorine dioxide. "The target concentration was not reached, but since photometric measurement was utilized, the exposure was extended accordingly and the end result was successful."

{includes ClorDiSys info} "Due to the selective oxidizing nature of chlorine dioxide it only reacts with molecules that are highly reduced (alcohols, alde-hydes, ketones, tertiary amines, and sulfur containing amino acids) which allows its activity to be much less influenced by organic soil loads" "Fumigation/ vapor: 360-1,800 ppm for 0.5-2 hours" "container of CD with fish tank bubbler to accelerate off gassing and a pump to circulate the gas. Although this method generated low levels of GCD--less than 500 ppm), with extended exposure times a successful decontamination" "Relative humidity of 80% increased efficacy, resulting in much shorter exposure time" "when GCD is generated by off gassing from liquid chlorine dioxide, corrosion of non-coated metal surfaces was observed after repeated exposure"

Small chamber experiments were used to study the consumption of gaseous chlorine dioxide and corresponding release of building disinfection by-products (BDBPs) for 24 common building materials. Test materials were exposed to a standard chlorine dioxide concentration of 700 ppm at a temperature of 24°C and RH of 75% for a 16 hour disinfection period. For most materials, the chlorine dioxide deposition velocity (vd) decreased significantly in the first 2 to 3 hours, indicating rapid consumption of reactive species on the surface of materials. The total BDBP mass released per unit area of material varied by over an order of magnitude between materials and did not correlate with chlorine dioxide deposition velocities.

******** {Some calculations and conclusions may need verification}

********** "Both the total microscopic count and the PCR count obtained for air samples decreased significantly. This could be caused by direct reduction of spores in the air or reduction of spores on surfaces that would serve as the source for the airborne spores. However, no decrease was observed in the semiquantitative analysis of amount of spores and hyphae in the stickytape samples collected from surfaces."

2020. During the severe pandemic of coronavirus, the development and deployment of efficient disinfection technology have attracted hospitals’ attention..

The present invention relates to polymer gel for releasing chlorine dioxide gas and a method for packaging food including the same. A chlorine dioxide solution, including a sodium chlorite solution and a buffer solution having a buffering range of pH 3-4, is absorbed into a polymer and therefore the chlorine dioxide gas of 0.2-5 ppm is continuously released for 14-18 days to prevent growth of harmful microorganisms during a distribution period. Consequently, the distribution period can be extended, when compared to an existing polymer gel, by maintaining freshness.

"Compared to gaseous chlorine dioxide, which spreads throughout an entire facility and penetrates into the smallest cracks, fogging has some limitations. Liquid fogging has many factors that reduce the ability of this agent to reach all the required areas for the required amount of time in order to achieve a successful decontamination cycle. Liquids have difficulty penetrating into crevices as they cannot overcome the surface tension." "Fogging with a liquid chlorine dioxide provides a more economical disinfection method compared to gaseous decontamination, offering a value proposition for less critical contamination control applications."

Application of chlorine dioxide in air via ultrasonic nebulizer was much more effective than via jet nebulizer

{Chlorine dioxide application in air via humidifier} " The efficacy of a given aerosolized biocide when used within a specific application will be dependent on the design of the aerosolization device and, hence, standardization of output (fog rate and droplet size) as well as the volume and topography of the environment to be decontaminated."

2020. Gaseous chlorine dioxide (ClO2) is a promising sanitizer for frozen products because of its efficacy under nonthermal and waterless conditions. Our pilot‐scale treatment of blueberries demonstrated t...

The Tufts New England Regional Biosafety Laboratory facility has been using chlorine dioxide gas for >5 years, and >100 decontaminations have been done at the r...

Chlorine dioxide gas decontamination services

Contamination control and biodecontamination articles, including related to COVID-19.

Contamination control and biodecontamination.

Hydrogen Peroxide is more corrosive to computers than chlorine dioxide.

Spore strips used to verify decontamination cycle's efficacy in water bottles, closed cabinets, HEPA air filters, laboratory cage lids, packed storage rooms, and medical isolators; and underneath equipment and dust.

Process description for chlorine dioxide gas decontamination

"...a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2)" "NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies."

Chlorine dioxide gas used to disinfect football player helmets and shoulder pads. "Bacteria were killed no only on the surface, but in the mesh covering and even into the foam pad beneath."

"Researchers at the U.S. Army Natick Soldier Research, Development and Engineering Center here, invented a next-generation disinfectant system that... is being used to sterilize medical equipment and electronic items used in the treatment of patients on the front lines of the war on Ebola in West Africa." "An important exponent of ClO2 is its versatility as a disinfectant suitable for any industry, ranging from textiles, medicine, wastewater treatment and public health, to food safety, personal hygiene, and household uses. ClO2 can be activated in small or large quantities and in varying strength levels from potent enough to sterilize medical instruments to mild enough to use in toothpaste to fight off germs in the mouth. " "Unlike other methods of preparing chlorine dioxide, no electricity or caustic acids are needed to activate the powdered ClO2, nor is clean water required, making it ideal for use in remote field locations."

{Applications at various Relative Humidity} Based on past remediation efforts, it is generally accepted that in order to achieve adequate kill, chlorine dioxide fumigation of a building requires a minimum relative humidity (RH) of about 65%, with a target ClO2 concentration and exposure time of 750 ppmv for 12 hours, for a total concentration of 9000 ppmv-hrs (CT). Other researchers have recommended a RH of greater than 70% for ClO2 concentrations between 125 and 10550 ppmv. Under current EPA guidelines, applications of ClO2 for building remediation require 75% relative humidity and an exposure of 9000 ppmv-hrs. {Includes info on corrosion mitigation.}

Maverick Transportation's Greg Johnsen is petitioning TMC to update their recommended practices for truck cab sanitizing in hopes to help combat COVID-19.

"...Though the perchlorate ion has been identified as a degradation product in the treatment of fruits and vegetables with gaseous ClO2, Smith et al. confirmed “in the presence of a chlorine dioxide sink and in the absence of light, perchlorate formation from chlorine dioxide is nil” and “the formation of chlorate and perchlorate can be minimized or essentially eliminated ... if chlorine dioxide sanitation processes are protected from light” "As it comes into contact with food surfaces, chlorine dioxide gas will be consumed by the oxidation of organic matter and micro-organisms present on food. Unlike chlorine dioxide gas in-solution, which decomposes into various oxychloro species upon its exposure to water, gaseous chlorine dioxide will decompose into only chlorine and oxygen when released to the atmosphere." "In-line with the results of Lee, we conservatively estimate that the residual chlorite concentration is approximately 70% of chlorine dioxide consumed in-reaction and that residual chlorate concentration is approximately 15% of chlorine dioxide consumed in-reaction. The reaction’s remaining 15% can be categorized as minor reaction products." "Chlorine, however, will rapidly be broken down in reactions with ultraviolet light or other atmospheric particles to form the chloride particle. "