Fluorine (F) is the first element of the halogen family and
the most reactive of all chemical elements. The term "fluoride"
refers to its ionic form (F-) and "fluorides" to
fluoride-containing compounds, both organic and inorganic.
Fluorine is never found by itself in nature but fluorides are found
everywhere: in soil, air, and water, as well as in plant and animal life.
Fluoride is commonly added to tap water, particularly in North America, and
used in dental products to help prevent tooth decay.
Fluorides are important industrial chemicals with a number of uses but the
largest uses are for the production of aluminium and specialty chemicals used
for refrigeration and air conditioning through fluorocarbons, for drinking-water
fluoridation and for the manufacture of fluoridated dental preparations.
In excessive amounts, fluoride can lead to fluorosis.
Inorganic fluorides are the most important for environmental exposure through
water and food. Based on quantities released and concentrations present
naturally in the environment as well as the effects on living organisms, the
most relevant inorganic fluorides are hydrogen fluoride (HF), calcium fluoride
(CaF2), sodium fluoride (NaF), sulfur hexafluoride (SF6)