Chemical & Biological Dynamics

****!!!!*** "Chlorine dioxide is classified by the World Health Organization as a fourth-generation A1, widely used, safe, and effective disinfectant. It is widely used in bleaching, water treatment, oil extraction, aquaculture, plants, fruits and vegetables, meat products, preservation of aquatic products, food sterilization and sterilization industries. The technology of chlorine dioxide produced by the combination reduction method is widely used in domestic papermaking related companies. In order to promote the application of chlorine dioxide, the effects of storage conditions on the stability of chlorine dioxide solution prepared by the combination reduction method and the experimental study of decomposition kinetics were studied. Experiments have shown that high temperature, high pH and high initial concentration accelerate the decomposition of chlorine dioxide solution, and the addition of sodium dihydrogen phosphate (NaH 2 PO 4 ) and dimethyl sulfoxide (DMSO) can inhibit the decomposition"

The product distribution from the decay of chlorine dioxide in basic solution changes as the ClO2 concentration decreases. While disproportionation reactions that give equal amounts of ClO2- and ClO3- dominate the stoichiometry at millimolar or higher levels of ClO2, the ratio of ClO2- to ClO3- formed increases significantly at micromolar ClO2 levels. Kinetic evidence shows three concurrent pathways that all exhibit a first-order dependence in [OH-] but have variable order in [ClO2]. Pathway 1 is a disproportionation reaction that is first order in [ClO2]. Pathway 2, a previously unknown reaction, is also first order in [ClO2] but forms ClO2- as the only chlorine-containing product. Pathway 3 is second order in [ClO2] and generates equal amounts of ClO2- and ClO3-. A Cl2O4 intermediate is proposed for this path. At high concentrations of ClO2, pathway 3 causes the overall ClO3- yield to approach the overall yield of ClO2-. Pathway 2 is attributed to OH- attack on an oxygen atom of ClO2 that leads to peroxide intermediates and yields ClO2- and O2 as products. This pathway is important at low levels of ClO2.

Includes "Effectiveness of chlorine dioxide against protozoa" "These values are 3–14 times less than those required for free chlorine, but approximately 20 times more than those required for ozone."

"The two viability methods produced significantly different results (P 0.05). Products of disinfectant concentration" "excystation is not an adequate viability assay." "Purified oocysts originating from three different suppliers were evaluated and showed marked differences with respect to their resistance to inactivation when using chlorine dioxide" "Finally, the study compared the relationship between easily measured indicators, including Bacillus subtilis (aerobic) spores and Clostridium sporogenes (anaerobic) spores, and C. parvum oocysts. The bacterial spores were found to be more sensitive to chlorine dioxide"

In this work, the application of advanced oxidation processes (AOPs) for the removal of antibiotics from water has been reviewed. The present concern about water has been exposed, and the main problems derived from the presence of emerging pollutants have been analyzed. Photolysis processes, ozone-based AOPs including ozonation, O3/UV, O3/H2O2, and O3/H2O2/UV, hydrogen peroxide-based methods (i.e., H2O2/UV, Fenton, Fenton-like, hetero-Fenton, and photo-Fenton), heterogeneous photocatalysis (TiO2/UV and TiO2/H2O2/UV systems), and sonochemical and electrooxidative AOPs have been reviewed. The main challenges and prospects of AOPs, as well as some recommendations for the improvement of AOPs aimed at the removal of antibiotics from wastewaters, are pointed out.

***!!!!*** "Chlorine dioxide exists in two isomeric forms: the symmetric OClO and the asymmetric ClOO. The ClOO isomer is thermodynamically more stable than OClO... However... very reactive" "OClO is kinetically stable at room tempreature, showing tno thermal reactivity in water" "90% of the electronically excited molecules dissociate; the remaining 10% undergo isomerization to form ClOO. In addition, the simulated kinetics show that the thermal decomposition of ClOO in water has a rate constant of 6.7 x 10 9[?] s-1."

"Biocides help kill or prevent the growth of microbes--keeping the public safe-- they are used to clean and disinfect homes, medical facilities and public spaces. Also, countless industries, from food production to manufacturing to gas extraction, rely on biocides in their day-to-day operations."

"Treatment of biofilms for 10 minutes with disinfectants at 1MIC or 2MIC reduced the biovolume of live cells. PAA (YE) and BZK (CS and YE) at 1MIC did not alter the percentage of dead cells relative to non-exposed biofilms, and their effect of countering biofilm was due principally to the detachment of cells. These results suggest that doses of PAA and BZK close to MICs might lead to the dissemination of live bacteria from biofilms with consequent hazards for public health."

"Toxicokinetics Chlorine dioxide can be rapidly absorbed through the gastrointestinal tract. Peak blood concentration levels can be reached within 1 h after a single dose administered orally. It can also be slowly absorbed through shaved skin with a half absorption time of 22 h. It seems unlikely that intact chlorine dioxide is absorbed by inhalation giving its highly reactive nature; it is more likely that its derivatives can be absorbed. Chlorine dioxide is metabolized to chlorite, chlorate, and mostly chloride. Most administered chlorine dioxide and its metabolites remain in plasma followed by kidneys, lungs, stomach, intestine, liver, and spleen. About 43% of orally administered chlorine dioxide is eliminated in the urine and feces within 72 h. It is not excreted via the lungs."

Sexual transmission is the most common pathway for the spread of Human papillomavirus (HPV). However, the potential for iatrogenic HPV infections is also real. Even though cleared by the Food and Drug Administration and recommended by the World ...

Bacteria isolated from washer disinfectors using chlorine dioxide as a high-level disinfectant were exposed to peracetic acid, chlorine dioxide and hydrogen peroxide to investigate their susceptibility and possible bacterial cross-resistance to these highly reactive oxidising biocides. A standard suspension test was used to establish a rate of kill of these biocides against two stable isolates (Bacillus subtilis and Micrococcus luteus). Suspension tests demonstrated that ‘in use’ concentrations were not always effective to provide the required disinfection efficacy within recommended exposure times and in some instances a 60min exposure was necessary to achieve a reduction in number by a factor of 105.

John Ware, Director of Envirolyte ECA UK Ltd, details how the Envirolyte disinfection product can aid in the fight against COVID-19.

A decontamination system suitable for decontaminating items of medical equipment such as endoscopes, the system comprising: (I) a plurality of pre-clean wipes comprising moist fabric members for wiping an item to be decontaminated; (II) a two-part sterilant system comprising: (a) a first part comprising a first reagent in a carrier medium; and (b) a second part which is miscible with the first part and which comprises a second reagent in a carrier medium; wherein the first reagent and the second reagent will react when mixed to provide a sterilising composition; the first part being contained in a dispenser ( 2 ) whereby it may be dispensed as a fluid, and the second part being absorbed or impregnated in a plurality of sterilising wipes ( 18 ) each of which comprises a fabric member in a sealed container ( 20 ); and (III) a plurality of rinse wipes, each rinse wipe comprising a moist, sterile, fabric member in its own sealed container ( 40 ).

The aim of this study was to compare the antimicrobial properties of a slow release noncorrosive chlorine dioxide with those of sodium dichloroisocyanurate to establish their possible use in the dental settings. Disinfectant solutions were prepared

Tristel Sporicidal Wipes are chlorine dioxide-based disinfectant wipes for disinfecting non-lumened semi-critical medical devices."

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These corrosion data are mainly based on results of general corrosion laboratory tests , carried out with pure chemicals and water solutions nearly saturated with air (the corrosion rate can be quite different if the solution is free from oxygen). All concentrations are given in weight-% and the solvent is water if nothing else is shown. The corrosion data apply to annealed materials with normal microstructure and clean surfaces, throughout.

{On pg 3} {May be mistaken in listing a 80,000 ppm chlorine dioxide concentration} "Chlorine Dioxide, 8% aqueous solution"

"The corrosion of A3 steel, copper, aluminum, stainless steel in 50 mg/L, 100 mg/L, 200 mg/L and 400 mg/L chlorine dioxide disinfection solution at room temperature was studied by the method of static weight-loss. The results showed that when the concentration of chlorine dioxide disinfection solution was 200 mg/L, the corrosion degree of aluminum was mild and that of copper was moderate; when the concentration of chlorine dioxide was 400 mg/L, the corrosion degree of A3 steel was severe and that of stainless steel was mild. The possible corrosion reason was analyzed."

"applications in which soil residues are frequent." "One sanitizer was an acidified solution of dilute sodium chlorite at pH 2.7; the other sanitizer was dilute chlorine dioxide (about 15 ppm) in tap water. Stainless steel types 304 and 316 corroded rapidly when exposed to the acidified chlorite solution. Chlorine dioxide near neutral pH 7.2 was noncorrosive to both type 304 and 316 stainless steels at a concentration of 100 ppm during 10 d of continuous exposure. This concentration is well above the typical use Concentration of 15 ppm; typical use time span is 15 min." "chlorine dioxide is of equal bactericidal activ- ity to sodium hypochlorite at one-seventh the concentration of hypochlorite, when used for sanitation of poultry processing water"

"composition of matter comprising a solid form of chlorine dioxide complexed with a cyclodextrin. The concentration of chlorine dioxide in said solid form is greater than approximately 5.8 percent by weight"

A process for producing aqueous chlorous acid solution in which chlorous acid, which is safe for the human body, is easy to handle, and less generates chlorine dioxide, is yielded and used as a disinfectant for a pretreatment in food processing. To an aqueous sodium chlorate solution is added sulfuric acid or an aqueous solution thereof in such an amount and concentration that the pH of the aqueous solution can be kept at 2.3-3.4 to thereby react them and generate chloric acid. Subsequently, hydrogen peroxide is added to the chloric acid in an amount which is equal to or larger than the amount necessary for a reduction reaction to thereby yield chlorous acid. Any one of inorganic acids, inorganic acid salts, organic acids, and organic acid salts, or two or more thereof, or a combination or these is added to the aqueous solution containing chlorous acid yielded, whereby the chlorous and acid can be present for long and the pH of the aqueous solution is regulated to regulated to 3.2-7.0. Thus, high bactericidal power is imparted thereto.

" The present invention is usable as a microbe disinfectant that is safe to human body and easy to handle as a microbe disinfectant for pretreatment in food processing and produces chlorous acid that generates little chlorine dioxide. The microbe disinfectant comprising a chlorous acid aqueous solution of the present invention can be utilized as a sterilizing agent, food additive, antiseptic, quasi-drug, medicine, etc." "Further, when the present invention is used as a microbe disinfectant, a microbe disinfecting effect was unexpectedly found to be enhanced by making the disinfectant acidic when applied to gram-negative microbes and approximately neutral when applied to gram-positive microbes. This is thus provided as the present invention. Further, it was found that the present invention additionally has an effect on various microbes to which an effect has not been shown conventionally." "This contributes to a delay in the progression of chlorous acid (HCIO2) to chlorine dioxide (CIO2) , which enables the manufacture of an aqueous solution comprising chlorous acid (HCIO2) that sustains chlorous acid (HCIO2) for an extended time and generates a reduced amount of chlorine dioxide (CIO2) ·" "it was surprisingly revealed that a strong acidity level is not necessarily important in microbe disinfection."