Chemical & Biological Dynamics

****!!!!*** "Both chlorine dioxide and iodine reacted with the capsid proteins of poliovirus and changed the pI from pH 7.0 to pH 5.8. However, the mechanisms of inactivation of poliovirus by chlorine dioxide and iodine were found to differ. Iodine inactivated viruses by impairing their ability to adsorb to HeLa cells, whereas chlorine dioxide-inactivated viruses showed a reduced incorporation of [14C]uridine into new viral RNA. We concluded, then, that chlorine dioxide inactivated poliovirus by reacting with the viral RNA and impairing the ability of the viral genome to act as a template for RNA synthesis."

***** "ClO2 at 10 μg ml−1 effectively reduced conidial germination of all decay fungi tested after treatment for 0·5 min. Chlorine dioxide only kills by contact, not systemically, and is effective only on exposed fungal propagules, such as those suspended in water or on the surface of fruit. It does not kill pathogens under the fruit skin or active infections. Chlorine dioxide can be difficult to use indoors because when a treated water stream is agitated or aerated, some of the ClO2 comes out of solution and enters the atmosphere. There is a permissible exposure level of 0·1 μg ml−1 in the air, but workers will respond to the odour before that level is reached. In USA, for this reason the recommended rate for indoor applications is μg ml−1 or less"

"The inactivation mechanisms were explored by analyzing the leakage of intracellular substances, the increase in extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA), and proteins as well as the changes in spore morphology. The kinetics of inactivation by chlorine dioxide fitted the Chick-Watson model, and different fungal species showed different resistance to chlorine dioxide inactivation, which was in the following order: Cladosporium sp.>Trichoderma sp. >Penicillium sp., which are much more resistant than Escherichia coli." "Regarding the three genera of fungal spores used in this study, chlorine dioxide was more effective at inactivation of fungal spores than chlorine." "The effect of disinfectant concentration and temperature was positive, and the impact of pH levels (6.0 and 7.0) was insignificant, whereas the influence of water matrices on the inactivation efficiency was negative. The increased concentration of characteristic extracellular substances and changes of spore morphology were observed after inactivation with chlorine dioxide and were due to cell wall and cell membrane damage in fungal spores, causing the leakage of intracellular substances and death of a fungal spore."

{Unsure whether study included chlorine dioxide?} "viability assessment methods of esterase activities and intracellular reactive oxygen species (ROS) were optimized, and the effects of chlorine-based disinfectants on fungal spores were evaluated by flow cytometry (FCM) and plating."

1987

2020 "Results showed that the antimicrobial effect of ClO2 (g) significantly decreases as the aw level and ClO2 (g) concentration decrease." "The results of this study may be used to design ClO2 (g) treatment processes to inactivate L. monocytogenes in low-moisture foods."

"The effectiveness of steady-state levels of gaseous chlorine dioxide (ClO2) against Tulane virus (TV), a human norovirus surrogate, on berries was determined. The generated ClO2 was maintained at 1 mg/L inside a 269 L glove box to treat two 50 g batches of blueberries, raspberries, and blackberries, and two 100 g batches of strawberries that were immersion coated with TV. The standardized/normalized treatment concentrations of ClO2 ranging from 0.63 to 4.40 ppm-h/g berry were evaluated. When compared to untreated TV contaminated berries, log reductions of TV were in excess of 2.9 log PFU/g for all berry types and conditions tested, indicating that ClO2 was highly effective. In general, the efficacy of all ClO2 treatments on log reductions of TV on all berries was not significantly different (p

Aims: To model survival curves of Dothiorella gregaria Sacc. and Fusarium tricinctum (Corda) Sacc. spores inoculated on fresh chestnut kernel exposed to aqueous chlorine dioxide (ClO2). Methods and ...

"This paper proposes that chlorine dioxide (ClO2) should be considered as an alternative to common antibiotics. ClO2 disinfects via oxidation and is highly selective due to its one‐electron transfer mechanisms." "...indicates that ClO2 is as effective as phenol in inhibiting bacterial growth." "In part two, ClO2 was found to be less effective than peniciliin against the three opportunistic pathogens. These results may be erroneous, however..."

****!!!! "The inactivation efficiencies vary greatly among different virus species. The inactivation rates for different serotypes within a family of viruses can differ by over 284%. Generally, to achieve a 4-log removal, the exposure doses, also being referred to as Ct values (mutiplying the concentration of ClO2 and contact time) vary in the range of 0.06–10 mg L−1 min. Inactivation kinetics of viruses show two phases: an initial rapid inactivation phase followed by a tailing phase. Inactivation rates of viruses increase as pH or temperature increases, but show different trends with increasing concentrations of dissolved organic matter (DOM). Both damages in viral proteins and in the 5′ noncoding region within the genome contribute to virus inactivation upon ClO2 disinfection."

****!!!!**** 1967 {This is 1 of at least 3 papers that derived differing theories on dynamics of E. coli after chlorine dioxide treatment} "Survival data are presented for a fecal strain of Escherichia coli exposed to three concentrations of chlorine dioxide at four temperatures... Initial experiments support the thesis that the mechanism of chlorine dioxide kill occurs via disruption of protein synthesis."

1965 "We found chlorine dioxide to be a more effective disinfectant than chlorine in sewage effluent at pH 8.5. Chlorine dioxide was also found to be a more stable bactericide in relation to pH in the range studied."

The present invention provides for a stabilized solution containing a halogen containing compound which is effective as a sterilizing or disinfecting agent, and a stabilizing agent which suppresses the chemical dissociation of the halogen compound such that the sterilizing capability of the solution is maintained for extended periods of time relative to the solution without the stabilizing agent. The halogen containing compound is selected from the group consisting of chlorine dioxide, bromine oxide, bromine chloride, monochloroamine, bromic acid, iodine monochloride, iodine trichloride and iodine monobromide. The stabilizing agent is a compound having at least one accessible sulphur containing group selected from the group consisting of cyclamic acid, dimethyl sulphoxide, glyoxyl sodium bisulphite, potassium sorbate, sodium cyclamate, sodium metabisulphite, sodium oxalate, sodium sulphite, sodium thiosulphate and thioacetamide. Processes and kits for sterilizing or disinfecting water and objects utilizing the stabilized solutions are also provided by the present invention.

There is disclosed, in one aspect, chlorous acid generating compositions useful for disinfecting substrates

****!!!!**** "activated with material provided by BCI Inc., which included phosphoric acid and a surfactant." "12-14 ppm free chlorine dioxide" [Note: Oxine also contains other active oxychlorine species] "Viable cell counts were reduced by more than 99.99% after 60 seconds" "These are significant reductions, especially since the viable counts are primarily from fungal spores rather than vegetative cells."

"Spores of Mucor piriformis were killed after a 4-min exposureat 1 mg ClO2 ml-1 or 30 sec exposure at 3 mg ClO2 ml-1,"

{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."

****!!!!*** "ule type that potentially had low sensitivity to ClO2. The information generated from this research indicates whether a narrow or wide range in rate of ClO2 is needed for efficacy against different fungal propagules as a result of the interactions of water properties (e.g., pH and water hardness) that vary with the source (e.g., ponds, wells, municipal water, and recirculating systems), in combination with the presence of nutrient leachates that collect in catchment ponds and ebb-and-flow systems" " a high reduction in viable propagules resulted when conidia or sporangiospores of Botrytis cinerea, Penicillium expansum, Mucor piriformis, and Cryptosporiopsis perennans... These papers demonstrated that concentration of ClO2 varies with time, with an equal mortality of propagules obtained at lower concentrations of ClO2 by lengthening the duration of exposure. " "A higher concentration of ClO2 was required at pH 8 than at pH 5 to achieve a lethal dose resulting in 50% mortality of spores (LD50). The addition of the divalent metal ion solution required an increase in ClO2 concentration to maintain a LD50. When combined with the nitrogen and hard water solution, the divalent metal ion solution placed a higher demand on ClO2 at pH 5 and a lower demand on ClO2 at pH 8,"

2005. The efficacy of chlorine dioxide (ClO2) in detoxifying two potential bioterrorism agents, the trichothecene mycotoxins verrucarin A and roridin A, was evaluated...

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"

Appendix B: "T VALUES* FOR 4-LOG INACTIVATION OF VIRUSES BY CHLORINE DIOXIDE pH 6-9"

"Table D-8. CT Values for Inactivation of GimYi” Cysts by Chlorine Dioxide...Table D-9. CT Values for Inactivation of Viruses by Chlorine Dioxide pH 6-9"

{Good FAQ info} "It delivers broad spectrum performance against bacteria, fungi, algae, viruses, and parasitic microorganisms. ClO2 kills vegetative microorganisms and effectively deactivates sporulated species."

The University of Oklahoma Libraries has used chlorine dioxide as a treatment for mold on books since 1991. This research project compared the pH leve…

A collection of chlorine dioxide-based mold removal chemicals have entered the report stronger, faster, and safer remediation.

{Effectiveness against mucor pathogens "Information obtained from CSI beta-lactam inactivation at Pharmaceutical facility. " and "Study performed by the University of Tennessee at Knoxville."}