The History of ClO2
1814
Chlorine dioxide is discovered by Sir Humphrey Davy, when he adds sulfuric acid (H2SO4) to potassium chlorate (KClO3).
1944
Chlorine dioxide is used for the first time to solve taste and odour issues in a water treatment plant at Niagara Falls, New York. The objective is to get rid of phenols in water.
1956
Brussels, Belgium, switches to chlorine dioxide from chlorine for its drinking water disinfection operations. This marks the first large scale use of chlorine dioxide for potable water treatment.
1967
The Environmental Protection Agency (EPA) of the United States first registers chlorine dioxide as a disinfectant and sanitiser. The registration is for chlorine dioxide in the liquid form. Indicated uses include food processing, handling and storage plants, bottling plants, washing fruit and vegetables, sanitising water, controlling odours, and treating medical wastes.
1970
Hundreds of municipal water systems successfully convert to chlorine dioxide. This happens across the United States and Europe; more so for the latter. The conversion is catalyzed by a safer environmental profile of chlorine dioxide over chlorine.
1983
The EPA recommends chlorine dioxide as a solution to trihalomethanes (THMs). When chlorine is used to disinfect water and make it potable (chlorination), THMs are produced as a by-product. THMs have been linked to cancer (i.e., they are carcinogenic). Chlorine dioxide does not produce THMs.
1988
The EPA registers chlorine dioxide in the gaseous form (produced from sodium chlorite) for use in sterilisation. Indicated uses include sterilising manufacturing and laboratory equipment, environmental surfaces, and rooms.
1990
Use of chlorine dioxide as a disinfectant, sanitiser and steriliser grows across many industries and countries. Some of the industries are the beverage industry, fruit and vegetable processing plants, pulp and paper industries, and industrial waste treatment sites. These industries are spread across the United States, the United Kingdom and Europe.
2001
Chlorine dioxide is one of the decontamination agents used by the United States government against the Anthrax attacks of 2001. The Anthrax attacks are a ghastly example of bioterrorism. The spores of a bacterium Bacillus anthracis are used, which can cause the life-threatening disease ‘anthrax’ in victims. The choice of chlorine dioxide is due to its established sporicidal and sterilising properties.
2005
Chlorine dioxide is used to eradicate mold and mildew from homes flooded by Hurricane Katrina in New Orleans, Louisiana. Chlorine dioxide can penetrate biofilms to effectively disintegrate them.
2013
The EPA registers ClO2, a novel chlorine dioxide generator and delivery system, as a disinfectant / sanitiser / tuberculocide / virucide / fungicide / algaecide / slimicide / deodoriser.
2014
The EPA meets the Center for Disease Control’s (CDC) criteria for use against the Ebola virus. Chlorine dioxide is a potent virucide.