Sodium fluoride is a chemical that consists of a combination of positively charged sodium ions and negatively charged fluoride ions. It exists as a white powder that easily dissolves in water. Both sodium and fluoride are essential minerals; the National Institutes of Medicine Food and Nutrition Board recommends adults take in 3 mg of fluoride daily. Although poisonous when ingested internally, sodium fluoride is used in small concentrations in both toothpaste and drinking water. A variety of industrial applications also use sodium fluoride.
Fluoride effectively prevents dental decay – a process in which bacteria damages the tooth structure. Toothpaste and various other dental hygiene products therefore use sodium fluoride. The most common form of fluoride used in toothpaste and fluoride mouth rinses is sodium fluoride, according to the Centers for Disease Control and Prevention. Fluoride toothpaste sold in the United States typically contains between 1000 and 1500 parts per million of sodium fluoride. Because ingesting too much sodium fluoride can result in poisoning, you should only use a pea-sized amount when brushing and avoid swallowing. Symptoms of sodium fluoride include abdominal pain, drowsiness, vomiting and unconsciousness.
Public water treatment systems add fluoride additives, which makes water one of the main dietary sources of fluoride. Treatment systems use one of three different sources of fluoride, with sodium fluoride remaining the source of choice, especially for small treatment plants, according to the Centers for Disease Control and Prevention. To ensure the safety of drinking water, the Environmental Protection Agency sets quality standards for all additives, including sodium fluoride. Because too much sodium fluoride can cause discoloration of the teeth, especially in children, the EPA limits the amount of fluoride added to drinking water to 4 mg/L, according to the CDC.
Because sodium fluoride is poisonous it is commonly used in pesticides, including fungicides and insecticides. The concentration of sodium fluoride in this type of product ranges from 15 percent to 95 percent, as listed by the Fluoride Action Network. Various types of adhesives and glues use sodium fluoride as a preservative. The presence of the sodium fluoride prevents the growth of bacteria, fungi and mold. Sodium fluoride is also used in making steel and aluminum products. The addition of sodium fluoride to the molten metal increases deoxidation producing a more uniform metal, according to the Environment Agency. Other industrial uses for sodium fluoride include glass frosting, stainless steel pickling and wood preservatives.