Chlorite is a disinfectant byproduct of the water treatment process. Chlorite occurs when chlorine dioxide breaks down. Chlorite ion can combine with metal ions to form solid salts (e.g., sodium chlorite). Sodium chlorite dissolves in water and forms chlorite ions and sodium ions. More than 80% of all chlorite (present as sodium chlorite) is used to make chlorine dioxide to disinfect drinking water. Sodium chlorite is also used as a disinfectant to kill germs.

Chlorite ions are mobile in water, and may move into groundwater. However, the reaction of chlorite ions with soils and sediments may reduce the concentration of chlorite ions capable of reaching groundwater. Chlorine dioxide is added to drinking water to protect people from harmful bacteria and other microorganisms. Most people will be exposed to chlorine dioxide and its disinfection by-product, chlorite ions, when they drink water that has been treated with chlorine dioxide.

Animal studies have shown effects of chlorine dioxide and chlorite that are similar to those seen in people exposed to very high amounts of these chemicals. In addition, exposure to high levels of chlorine dioxide and chlorite in animals both before birth and during early development after birth may cause delays in brain development. The levels to which the animals were exposed were much higher than levels that would likely be found in drinking water that has been disinfected with chlorine dioxide.

Children exposed to large amounts of chlorine dioxide or chlorite would likely be affected in the same manner as adults. Exposure to chlorine dioxide gas in young children, however, might more quickly reduce the ability of blood to carry oxygen than in adults, making breathing more difficult. If infants or babies still in their mother's womb were exposed to large amounts of chlorine dioxide, it might cause parts of their brains to develop more slowly. This has been seen in young animals, but has not actually been seen in humans.

Epic Water Filters expect to test our products for the removal of Chlorite in 2019. Currently we have tested all products for the removal of Chlorine.