Chlorine dioxide is a gas that has the chemical formula ClO2, is a very effective, indoor climate-neutral and safe means of combating microbiological pollution. Chlorine dioxide is used worldwide for the purification of drinking water and drinking water systems (both for humans and animals), as well as for the disinfection of waste water. In addition, the substance is also effective for mold and odor remediation. In various contexts, chlorine dioxide has been assessed and approved by a number of authorities, including the US authorities EPA and FDA.
A chemical breakdown by microorganisms
Chlorine dioxide is very effective against bacteria and viruses in concentrations as low as 0.1 ppm. Not only does the substance effectively kill free-floating microorganisms, but it is also very effective at disinfecting surfaces with fixed bacteria in the form of biofilm – a thin film of bacteria on the surface of a material.
With a minimal contact time, chlorine dioxide is used effectively against many pathogenic organisms (and their resting stages). Furthermore, chlorine dioxide's ability to break down biofilms means that the regrowth of microorganisms is greatly delayed and, with continuous addition of very low concentrations, completely prevented.
Due to its mechanism of action, which consists of a chemical breakdown of the organism's cell membrane by oxidation, no resistance to chlorine dioxide develops.
Very effective for disinfection
Infection with microorganisms is the cause of disease outbreaks in both humans and animals. In general, we have a very high degree of control over the microbiological quality of our drinking water in Denmark, so it is rare that we see disease outbreaks due to water quality. But if we are to maintain the high standard, preventive disinfection of containers and facilities is an ongoing need. Drinking water systems in animal stables are to a greater extent exposed to long service times and low flow, where water-borne infections can be a real and troublesome problem.
Out in the world, infections by Listeria, Salmonella, Shigella and E. Coli are often seen, which originate from food and a number of cases of infections from water installations in hotels, offices and cruise ships caused by Legionella, Noro virus, Cryptosporium, etc.
Common to the above challenges is that chlorine dioxide, even in very low concentrations, can prevent the growth of microorganisms, as a continuous addition of between 0.2 and 0.8 ppm has proven to be particularly effective after an initial sterilization at a concentration of around 10 ppm. Since chlorine dioxide is a gas that is dissolved in the water, and since it is a stable solution, it can be transported around with the water when disinfecting water systems, and thus come into close contact with both the biofilm that sits on the inside of pipes and tanks as the free-floating microorganisms. When chlorine dioxide comes into contact with the microorganisms, it penetrates their cell membrane and thereby destroys the basic life processes. This penetration is different from several other oxidative products that just “sear the surface” of everything they come into contact with.
The same process occurs when chlorine dioxide is used in connection with mold remediation and in remediation after rising sewage, where a concentration of 1000 ppm and a contact time of 60 seconds is enough to ensure complete sterilization of even heavily mold-infested surfaces.
An indoor climate-neutral agent
Chlorine dioxide's effectiveness is due to the fact that the substance is very reactive. This high reactivity is also the reason that free chlorine dioxide is broken down very quickly by light. During the decomposition, chlorine dioxide is converted into oxygen and sodium chloride (common table salt), which is why it is a neutral indoor climate agent.
Chlorine dioxide in Protox's work
Protox offers the chlorine dioxide technology for use in the following areas:
- Mold remediation where the products ProtoxHysan and ProtoxBiox is used
- Remediation after rising sewage, where the products ProtoxHysan and ProtoxBiox are used
- Disinfection of drinking water systems for humans and animals, where the products ProtoxBiox and ProtoxCidox are used
- Disinfection of irrigation systems in nurseries where the products ProtoxBiox and ProtoxCidox are used
- Odor remediation, both delivered in liquid form and as a gas-generating solid, where the products ProtoxHysan and ProtoxAbScent
Note: In connection with odor removal, it is not recommended to use products with chlorine dioxide on "soft" surfaces such as upholstered furniture, textiles and carpets, as it has a bleaching effect. Here it is recommended to use instead ProtoxOdourfree, which does not contain chlorine dioxide and which has been developed based on a biological process with bacterial cultures and enzymes.