Fluoride occurs naturally in all water supplies. Geographically the level of fluoride can vary depending on the geology of the area.
Fluoridation is the term used to describe the action of elevating the naturally occurring level of fluoride in water to a chosen higher level.
In England, fluoridation schemes target the final level of fluoride at one milligramme per litre of water. This is equivalent to one part per million. In some regions, fluoridation is undertaken at the request of certain Strategic Health Authorities and is carried out I accordance with strict legal guidelines.