News

International Scientific Review – 2025

A comprehensive scientific review published in July 2025 in the journal Desalination and Water Treatment* confirms that chlorine dioxide (ClO₂) is an important alternative in modern water disinfection technologies, providing effective microbiological protection while generally producing significantly lower levels of harmful organic disinfection by-products compared with conventional chlorination.

High Microbiological Efficacy

Chlorine dioxide is effective against bacteria, viruses, fungi, and certain resistant microorganisms. According to the research reviewed in the study, concentrations as low as 0.1–1.0 mg/L, with contact times of just a few minutes, can achieve significant microbial inactivation.

In one comparative study, a 98% reduction in Staphylococcus aureus was achieved with 1.5 mg/L chlorine dioxide, whereas conventional chlorine required a concentration of 2.5 mg/L.

The technology also demonstrated favorable results against Pseudomonas species and spores of several fungal species.

Significantly Lower Formation of Organic Disinfection By-Products

One of the most important advantages of chlorine dioxide over conventional chlorination is the reduced formation of halogenated organic disinfection by-products.

In a comparative study cited in the publication, conventional chlorination produced:

- 30.3 times higher concentrations of trihalomethanes (THMs),
- 5.4 times higher concentrations of haloacetic acids (HAAs),

compared with chlorine dioxide disinfection.

These findings are particularly significant for drinking water safety and the development of advanced water treatment technologies.

Effective Oxidation and Improved Water Quality

Beyond disinfection, chlorine dioxide can be applied at several stages of water treatment. It can facilitate the removal of iron and manganese, reduce certain compounds responsible for unpleasant tastes and odors, and oxidize selected pharmaceutical residues and organic micropollutants.

In experiments reviewed in the study, reductions of 98% for diclofenac and 99.4% for sulfamethoxazole were achieved under specific treatment conditions.

Importance of On-Site Chlorine Dioxide Generation

The research highlights the importance of on-site chlorine dioxide generation, automated dosing, and continuous water quality monitoring.

Modern generator technologies, precise concentration control, and digital process supervision can enable the optimization of disinfection performance and more efficient chemical consumption.

This development approach is consistent with the concept behind the CLOOROGEN electrochemical chlorine dioxide generator and CLOORO automated water treatment technology.

Conclusion

The 2025 international scientific review supports the significant potential of chlorine dioxide in modern drinking water treatment, improving microbiological safety and reducing the formation of harmful organic disinfection by-products.

The research findings provide a favorable scientific foundation for developing a new generation of water treatment systems based on on-site chlorine dioxide generation, automated dosing, and continuous quality monitoring.

Scientific reference: Mzinyathi, M. et al. (2025). Chlorine dioxide drinking water pre-oxidation and disinfection: A review of its effectiveness, mechanisms, and disinfection by-products. Desalination and Water Treatment, 323, 101340.

DOI: https://doi.org/10.1016/j.dwt.2025.101340

Cold-chain terminal sterilization is used for products that must be manufactured, stored, and maintained with a carefully controlled temperature range, such as temperature-sensitive drugs and vaccines in prefilled syringes or autoinjectors containing temperature-sensitive drugs. Chlorine dioxide (ClO2) is an ideal sterilant for cold-chain terminal sterilization because it forms a true gas at room temperatures (15°C/59°F – 25°C/77°F), with a reliable and consistent process, with excellent penetration, and does not require elevated temperatures. In the current study, we validated the efficacy of ClO2 on cold-stored prefilled syringes as well as tested ClO2-sterilized samples and non-sterilized controls for residual sterilant on the prefilled syringe samples and the ingress of sterilant into the prefilled syringe samples. Residual sterilant remaining on a load after sterilization could cause chemical exposure to patients and negatively affect healthcare worker safety, among other things. Sterilant ingress into a medication could result in chemical contamination, drug degradation, and changes to drug formulation. Few studies have been published on ClO2 residue or ingress during terminal sterilization. Through this descriptive analysis of residual and ingress testing results, we demonstrate that chlorine dioxide sterilization leaves chlorite and chloride residuals at acceptably low levels. The residual chlorite average was 0.74 mg/L (control) and 0.82 mg/L (sterilized), which are below the maximum contaminant acceptable level of 1.0 mg/L. We also demonstrated that there was no evidence of any ingress,and that the amounts remained at acceptably low levels: average ingress chlorite was 0.78 mg/L (control) and 0.72 mg/L (sterilized), below the maximum contaminant acceptable level of 1.0 mg/L. Chlorate has no known maximum contaminant level. ClO2 sterilization is an excellent alternative to ethylene oxide sterilization for cold-chain sterilization because it is sustainable, non-carcinogenic, and does not leave harmful residuals, nor does it ingress into the drug product. This study helps demonstrate that ClO2 is a viable primary or alternative sterilization modality for medical device manufacturers.

• https://doi.org/10.1371/journal.pone.0321345

Effectiveness of Chlorine Dioxide (ClO₂) Against Yersinia pestis (the Plague-Causing Bacterium)
On October 2, 2026, Darya Shipilova, a 28-year-old employee of the Siberian Plague Research Institute in Irkutsk, died from severe pneumonia of unknown origin. According to unofficial sources, the researcher had previously accidentally broken a test tube containing the plague-causing bacterium (Yersinia pestis).
Chlorine dioxide (ClO₂) effectively inactivates Yersinia pestis, the bacterium responsible for plague, in water, on surfaces, and in enclosed environments.
1. Effectiveness in Water
- Concentration and Contact Time: A chlorine dioxide concentration of 0.25 mg/L in drinking water achieves at least a 3-log reduction (99.9% inactivation) of Yersinia pestis within 10 minutes under typical temperature (5–25°C) and pH (7–8) conditions.
- Application: Chlorine dioxide concentrations commonly used in water treatment may be suitable for inactivating Yersinia pestis in contaminated drinking water distribution systems.
2. Effectiveness on Surfaces and in Room Decontamination
Disinfection Using Aqueous Chlorine Dioxide Solutions
- Concentration and Contact Time: A chlorine dioxide solution at a concentration of 200–250 mg/L can kill or completely inactivate Yersinia pestis in liquids and on contaminated surfaces within 5 minutes. Under certain experimental conditions, a contact time of just 1 minute may be sufficient on clean surfaces.
Room Decontamination Using Gaseous Chlorine Dioxide
- Concentration and Environmental Conditions: Gaseous chlorine dioxide, for example at concentrations of 377–385 ppm and under appropriate environmental conditions, including approximately 65% relative humidity, can achieve complete inactivation of vegetative Yersinia pestis bacterial cells or a significant reduction of several logarithmic orders of magnitude.

Disinfection of the water network and faucets has begun, alongside modernization of the water piping infrastructure. During these works, the hospital is providing bottled drinking water to patients.
Chlorine dioxide (ClO₂) is one of the most effective and widely used industrial biocides for controlling Legionella bacteria and disinfecting water distribution systems. While conventional chlorine (Cl₂) has limited effectiveness against biofilms formed inside pipelines, chlorine dioxide acts directly on bacterial cell membranes and genetic material through oxidative mechanisms, including electron-transfer reactions and electrophilic attack.