The colourless or white inorganic solid Sodium fluoride readily soluble in water is the common source of fluoride used in toothpaste and fluoride mouth rinses according to the Centres for Disease Control and Prevention. Sodium fluoride is classed as toxic by both inhalation (of dusts or aerosols) and ingestion and has been shown to affect the heart and circulatory system. It is used as a cleaning agent and as an insect poison.
As of 2014 there have been reported cases of fluoride poisoning associated with the ingestion of fluoride-containing toothpaste. As an example, one of these involved a 45 year old woman who came to her doctor complaining of unusual swelling and pain in her fingers. Tests showed elevated levels of fluoride in her urine and blood. When questioned about this, the woman admitted to the regular ingestion of large amounts of toothpaste, consuming a tube of it every two days and swallowing 68.5 mg of fluoride every day, because she “liked the taste”. While switching to a non-fluoride form of toothpaste, the fluoride levels in her blood and urine dropped dramatically and her condition subsided the effects on her internal organs remained untested.
All the important intake of fluorine is by mouth. Primarily due to how readily water soluble a poison it has proved to be. When swallowed, fluoride is absorbed via the stomach and intestines, and passes rapidly round the body in the bloodstream. Peak blood levels appear in 30-60 minutes after swallowing. The most soluble fluoride compounds, such as sodium fluoride in water. The ion is incorporated into the mineral matrix of bone. Consequently, given the research in the late 90’s first performed by Jennifer Luke showing that the pineal gland simply absorbed more fluoride than any other physical matter in the body, even bones, there is clear evidence that, while superficially flushed out by the blood and urine continual fluoride use is absorbed by the organs to a detrimental effect.