Why is Chlorine Dioxide Useful as a Disinfectant?

25 May,2021 | Blog

We are surrounded by microorganisms, the source of diseases. To ensure the health of people, these microorganisms should be removed from food, water, hard surfaces, and other areas using disinfectants. And when it comes to using chemical compounds as disinfectants or antimicrobial agents, Chlorine Dioxide (ClO2) has arguably no competition. It constitutes two atoms of oxygen and one atom of chlorine and exists in gaseous form at room temperature with a yellowish-green or red coloration. But when applied to water, it can get fully dissolved in it and remove all types of microbes.

Chlorine dioxide

Due to its powerful property as a disinfectant, chlorine dioxide has many applications, both in industrial and municipal areas. The non-toxic compound has the power to remove microorganisms such as bacteria, viruses, protozoa, and several parasites present in water and turning it drinkable. However, CIO2 should be used sparingly and in minimal quantity (0.8ppm or less) in drinking water. Some of the applications of CIO2 are as follows:

Disinfectant for water

In general, chlorine has been used as a disinfectant for ages to clean turbid waters. But it comes with some disadvantages:

  • Not much effective in turbid waters
  • Does not offer full protection against protozoa
  • The residue leaves a distinct taste and odor

However, with chlorine dioxide, the sterilizing power is greater as it is not affected by the pH value of water. Also, CIO2 uses the oxidation process to disinfect water where its electrons attack microbes that give or attract electrons thus removing most of the microorganisms. And when it is about eliminating the bacterial cells, CIO2 interrupts several cellular processes within the bacterial cells and prevents the production of proteins. For viruses, chlorine dioxide interacts with peptone and prevents the formation of proteins. Thus, the chemical compound has widespread usage in treating sewage water, cooling tower water, or water in swimming pools, among others.

Medical usage

In the medical field, the equipment, tools, and surfaces should be disinfected to eliminate the possibility of any microbial contamination. Such contamination can severely impact the health of patients suffering from various illnesses with compromised levels of immunity. The proven capability of CIO2 in removing microorganisms such as Legionella Pneumophila (bacteria causing a severe type of pneumonia) means the chemical can be used to keep the environment sterile. Also, since CIO2 is more effective at eliminating bacteria and viruses than chlorine, it should be used more in the medical field.

For treating water

Drinking water can be a major carrier of disease-causing microorganisms. So, in order to ensure the safety of drinking water, CIO2 is used as a disinfectant agent. It helps to prevent the growth of bacteria and algae in various stages of the water treatment process. The chemical oxidizes any floating particles in water and reduces its turbidity. Further, it is arguably the only chemical that can remove biofilm formed in water and prevent the growth of microorganisms. And since it can remain active in water for around 48 hours, it can prevent the growth of biofilm. Therefore, use the chemical during the pre-oxidation phase of water treatment and make drinking water safe for human consumption.


Chlorine dioxide has many applications in the industry such as removing contaminants in cooling towers and improving the efficiency of industrial processes and machines. It is powerful to remove microorganisms in several areas and prevent diseases. Lastly, given the hazardous nature of the chemical in pure gaseous form, proper care and safety measures should be taken while using it.

Tags: Chlorine Dioxide