CDC – Water Fluoridation Additives – Engineering Fact Sheet – Community Water Fluoridation – Oral Health

Sources of Fluoride Additives

Most fluoride additives used in the United States are produced from phosphorite rock. Phosphorite is mainly used for manufacturing phosphate fertilizer. Phosphorite contains calcium phosphate mixed with limestone (calcium carbonates) minerals and apatite—a mineral with high phosphate and fluoride content. It is refluxed (heated) with sulfuric acid to produce a phosphoric acid-gypsum (calcium sulfate-CaSO4) slurry.

The heating process releases hydrogen fluoride (HF) and silicon tetrafluoride (SiF4) gases, which are captured by vacuum evaporators. These gases are then condensed to a water-based solution of approximately 23% FSA.

Approximately 95% of FSA used for water fluoridation comes from this process. The remaining 5% of FSA is produced in manufacturing hydrogen fluoride or from the use of hydrogen fluoride to etch silicates and glasses when manufacturing solar panels and electronics.

Since the early 1950s, FSA has been the main additive used for water fluoridation in the United States. The favorable cost and high purity of FSA make it a popular additive. Sodium fluorosilicate and sodium fluoride are dry additives that come from FSA.

FSA can be partially neutralized by either table salt (sodium chloride) or caustic soda to get sodium fluorosilicate. If enough caustic soda is added to completely neutralize the fluorosilicate, the result is sodium fluoride. About 90% of the sodium fluoride used in the United States comes from FSA. Sodium fluoride is also produced by mixing caustic soda with hydrogen fluoride.

Regulatory Scope on Additives

The U.S. Environmental Protection Agency (EPA) has authority over safe community drinking water, as specified in the Safe Drinking Water Act. On the basis of the scientific study of potential harmful health effects from contaminated water, the EPA sets a Maximum Contaminant Level (MCL) concentration allowed for various organisms or substances.

Although the EPA does not specifically regulate levels of “direct additives,” which are additives added to water in the course of treatment, it does specify that the addition of chemicals as part of the treatment process should not be more than the MCL concentration for regulated substances. This MCL limit includes the levels naturally occurring in the source water, plus the contribution from direct additives. In 1979, EPA executed a Memorandum of Understanding with the U.S. Food and Drug Administration (FDA) to establish and clarify areas of authority in controlling additives in drinking water. FDA has regulatory oversight for food additives, which includes bottled water, and EPA has regulatory oversight of direct additives in public drinking water supplies.

https://web.archive.org/web/20160329155217/https://www.cdc.gov/fluoridation/factsheets/engineering/wfadditives.htm

“It’s POLLUTION , Stupid! “

Fluoridating drinking water with recovered pollution is a cost-effective means of disposing of toxic waste.

Health Canada Admits, in a reply to a freedom of information request, they can supply no  evidence that fluoridation is safe or effective – Welcome to Fluoride Free Sudbury