Chlorine Dioxide:
What is it?
Chlorine Dioxide (CIO2) is a gaseous compound that is extremely volatile, chemically unstable, and thus highly reactive. It is therefore a strong oxidant and a product capable of ensuring rapid disinfectant action. For this reason, if properly generated and dosed, it can be successfully used, among various applications, for the disinfection of drinking water and for the prevention of Legionella risk.
What is it?
Chlorine Dioxide (CIO2) is a gaseous compound that is extremely volatile, chemically unstable, and thus highly reactive. It is therefore a strong oxidant and a product capable of ensuring rapid disinfectant action. For this reason, if properly generated and dosed, it can be successfully used, among various applications, for the disinfection of drinking water and for the prevention of Legionella risk.
Is chlorine dioxide dangerous?
Chlorine dioxide is an extremely reactive compound with strong oxidising power. For this reason it must be handled only with appropriate expertise to prevent its use from causing critical issues.
Due to its instability, it is frequently produced on-site, directly where it is used, thanks to specifc generators. These generators must be equipped with safety systems to prevent malfunctions that could lead to potentially explosive reactions. This is why SANISWEEP is equipped with all the necessary technological solutions to ensure the highest safety standards.
What is the permissible limit of chlorine dioxide in drinking water?
Considering the potential health effects when used in drinking water, according to the WHO, no guideline value can be defined for this product as it decomposes immediately upon ingestion. Therefore, it is necessary to refer to the limits for chlorite and chlorate, the main disinfection by-products resulting from its use. For these by-products, the Directive (EU) 2020/2184 set a limit of 0.25 mg/l (with a derogation up to 0,7 mg/l in some Countries).
In this context, it is crucial that the system chosen for the production of chlorine dioxide ensures the highest reaction yield, in order to limit the presence of chlorite or chlorate (used as reagents for its production) as uncombined precursors.
For this reason, SANISWEEP has been developed to ensure a chlorine dioxide generation reaction yield exceeding 95%.
Can chlorine dioxide be used for the control of Legionella?
Yes, according to national and international guidelines for the prevention of Legionella risk, chlorine dioxide can be used for this purpose. It is suggested to use concentrations ranging from 0.1 to 1 mg/l for continuous treatment. However, given the high oxidising power of this product, prolonged use can lead to undesirable effects on systems (corrosion of metals and embrittlement of plastics). In such cases, it is essential that disinfection management is carried out by experienced personnel who can optimise the disinfectant action and minimise the impact on the condition of the pipes.
Due to its high reactivity and rapid action, chlorine dioxide is suitable for shock treatments with corrective purposes: in this case, guidelines recommend the use of concentrations of at least 5-10 mg/l.
In water supply systems, is chlorine dioxide more suitable for primary disinfection or for secondary disinfection?
Chlorine dioxide is a highly reactive molecule with strong oxidising power. For this reason, it is certainly suitable for applications such as primary disinfection, which benefit from the rapidity of its disinfectant action, requiring low concentrations and short contact times.
Conversely, its high instability makes it less suitable for ensuring residual disinfection along distribution networks, especially if these are large, branched or characterised by long water residence times. In such conditions, a more persistent disinfectant, such as SANIKILL, is more appropriate.
Can chlorine dioxide be consumed in drinking water?
If chlorine dioxide is present in drinking water as a disinfectant, the water is potable as long as it is dosed in concentrations that do not generate concentrations of its disinfection by-products, chlorite and chlorate, exceeding 0.25 mg/l, according to the Directive (EU) 2020/2184.
Under these conditions, the chlorine dioxide present in the water can be consumed without any adverse health effects.
Conversely, it is absolutely necessary to avoid the ingestion of any chlorine dioxide-based product marketed as a “medication” for the treatment of various diseases. If ingested in high concentrations and in an uncontrolled manner, it can cause serious damage to the mouth, oesophagus, and stomach.
