Disinfectants are chemical used to kill microorganisms on objects or in fluids. This is done to reduce the risk of those microorganisms infecting humans or other living creatures. Halogens, a series of non-metal elements that are lethal to living organisms, are commonly used in disinfectants. The halogens are fluorine, chlorine, bromine, iodine and astatine. The amount of a halogen used in a disinfectant is sufficient to kill microorganisms but not enough to pose a significant risk to larger organisms.
Chlorine bleach is a commonly used disinfectant. Approximately 3 to 6 per cent sodium hypochlorite is added as a disinfectant to produce this form of bleach. It is used in a variety of industrial and consumer applications. Consumers most commonly use bleach for washing clothes. Industrial applications use it to bleach materials, such as wood pulp, fat and beeswax, to make them a lighter colour. Not all bleach is based around chlorine for disinfection. Oxide and peroxide bleaches use non-halogen chemicals for disinfection.
Chlorine Water Disinfection
Chlorine is a commonly used disinfectant for water purification. The purpose of chlorine in the purification process is to kill pathogenic microorganisms in the water. Pure chlorine can be used for this purpose, but chlorine-containing compounds are also used. These compounds are chloramine, chlorine dioxide and sodium hypochlorite. The process of using chlorine or chlorine compounds as a water disinfectant is referred to as chlorination.
Bromine Water Disinfection
Bromine is an alternative to chlorine for water disinfection. It originally came into use for this purpose when chlorine became scarce during World War II. Bromine is still used as a water disinfectant because of its properties. Bromine absorbs more quickly into water than chlorine. It is also easier to remove from the water after disinfection is completed. Bromine is corrosive to metals, and requires higher concentrations than chlorine when it is used as a disinfectant.