fluorid

Fluorid, or fluoride ion (F−), is the negatively charged form of fluorine. In chemical contexts, compounds containing fluoride ion are called fluorides, such as sodium fluoride (NaF), potassium fluoride (KF), and calcium fluoride (CaF2).

Fluoride occurs naturally in the Earth's crust as fluorite (CaF2) and is present in small amounts in many groundwater sources and foods. It is released during mineral processing and produced industrially for various applications. Because fluoride ions are highly reactive in solution, they are usually supplied as salts rather than as free ions.

Fluoride has multiple commercial uses. It is added to some public drinking water and to toothpastes to reduce dental caries; varnishes and gels containing fluoride are used in dentistry. Industrial uses include the flux for aluminum smelting (cryolite and fluorides), glass and enamel production, and etching. In some contexts, fluoride compounds are used in pesticides or as laboratory reagents.

Health effects: At low doses, fluoride can help prevent tooth decay. At higher intake, fluoride can cause dental fluorosis in children, and chronic excessive exposure can lead to skeletal fluorosis. Acute fluoride poisoning is possible with large doses. Safety guidelines vary by country, with organizations such as WHO and national agencies recommending intake limits and set maximum contaminant levels for drinking water.

Environmental and regulatory notes: Fluoride is naturally present in water and air but can be elevated near industrial sources. Water treatment and defluoridation technologies are used to adjust fluoride levels. Public health decisions about fluoride balance weigh dental benefits against potential risks, and monitoring is common in water systems.