People buy sodium chlorite because it is a necessary component for certain kinds of water purification systems. In addition, the chemical is also used to bleach textiles, wood pulp and lipids on an industrial scale.
Sodium chlorite is frequently used to treat water in industrial settings. Many municipal drinking water systems use it as an antimicrobial. In addition, it is sometimes used to make waste water less odorous.
Sodium chlorite is also widely used in industry as a bleaching agent. When an acid is added to sodium chlorite, it breaks down into chlorine dioxide, a caustic chemical that serves as a powerful bleach. The bleach lightens the color of a variety of products, including certain fabrics.
Although it is effective as an antimicrobial, it is considered dangerous to use sodium chlorite to kill microbes within the human body by directly ingesting it. The FDA considers usage of sodium chlorite in this capacity hazardous to one's health.