While fluoride is naturally occurring in the world’s water supply, in some places, there isn’t enough there to give people the oral health benefits.
For that reason, thousands of communities across the country have opted to add fluoride to the water to reach optimal levels.
The question and concern for many is just exactly what it is that’s added to the water and what is the difference between additive and the naturally occurring fluoride.
According to the Centers for Disease Control, there are three different types of fluoride additives approved for use in the United States: sodium fluoride, sodium fluorosilicate and fluorosilicic acid.
In simple terms, sodium fluoride is a white, odorless material available either as powder or crystals while sodium fluorosilicate is a white or yellow-white, odorless, crystalline material. Fluorosilicic acid is the liquid form, which is white to straw-colored.
Sodium fluorosilicate and fluorosilicic acid are sometimes referred to as silicofluoride additives.
The two dry forms of fluoride additives must be dissolved in a solution before being added to the water supply unlike the fluorosilicic acid, which can simply be added to water as is.
Fluorosilicic acid is also referred to as hydrofluorosilicate, FSA or HFS.
It is the most commonly used additive for water fluoridation in Nebraska and across the country, followed by the two dry forms.
The liquid form, which Hastings Utilities would use in Hastings, is derived from production of phosphate fertilizers.
According to the CDC’s Web site, it is formed when phosphate rock, which is comprised of calcium phosphate, calcium fluoride, apatite ore and limestone, is mixed and heated with sulfuric acid to form a phosphoric acid-gypsum slurry, the starting point to make pelletized phosphate fertilizers.
The hydrogen fluoride and silicon tetrafluoride that would otherwise be left in the gypsum slurry is deliberately recovered by evaporators and condensed to a high purity fluorosilicic acid that can be used for water fluoridation.
The two dry fluoride additives are created by neutralizing the fluorosilicic acid with either sodium chloride, commonly known as table salt, or caustic soda.
Many people believe fluoride is the residue of production from pesticides, rodenticides or the nuclear industry.
The American Dental Association addressed those concerns along with those about it being a byproduct of fertilizer in its “Fluoridation Facts” book.
“From time to time opponents of fluoridation allege that fluoridation additives are byproducts of the phosphate fertilizer industry in an effort to infer the additives are not safe. Byproducts are simply materials produced as a result of producing something else — they are by no means necessarily bad, harmful or waste products,” the book states.
Another example of a byproduct is distillers grain, which comes from the production of ethanol. It is fed to cattle rather than simply being disposed of, according to the Nebraska Ethanol Board.
To ensure the public’s safety, each of the fluoride additives must meet standards as set by the American Water Works Association (AWWA) and National Sanitation Foundation International/American National Standards Institute (NSF/ANSI). Both of these entities are nonprofit, nongovernmental organizations.
The AWWA prepares standards for the manufacturing, quality, and verification of the fluoride additives, while NSF/ANSI prepares the standards that cover impurities of drinking water treatment additives from their production and distribution to user, and documents the purity of additives.
The NSF/ANSI standards were developed by a consortium of associations, including NSF International, AWWA, ANSI, the Association of State Drinking Water Administrators, and the Conference of State Health and Environmental Managers.
These entities ensure that fluoride, at the concentrations found in optimally fluoridated water, is not toxic according to generally accepted scientific knowledge.
But what exactly is the difference between natural and added fluoride? Is there a difference?
Kip Duchon and William Bailey, two officials with the CDC, both agree that naturally occurring and added fluoride are the same once in the water.
“Fluoride is fluoride whether it’s natural or artificial. No matter what compound, it all acts the same,” said Bailey, a dental officer with the CDC’s Division of Oral Health.
Duchon, the CDC’s National Fluoridation Engineer, said naturally occurring fluoride is mostly calcium fluoride coming from geological rocks.
The fluoride additives have different names simply because the sodium, calcium or tetrafluoride are used as compounds to hold the fluoride until it is put into the water.
“In all cases, it all dissolves to fluoride and fluoride is fluoride in water,” Duchon said.
Both men said scientific studies in recent years have reaffirmed the scientific belief that fluoride is the same no matter where it comes from.
“What we think is true,” Bailey said. “Fluoride is fluoride.”