Fluoride is a naturally occurring mineral found in trace amounts in most water sources. It is also intentionally added to many public water systems at a recommended level of about 0.7 milligrams per liter to help prevent dental decay. This practice, known as community water fluoridation, is recognized for its positive effect on oral health. For those who wish to eliminate this compound from their water, understanding the science of distillation provides a definitive answer.
The Distillation Process
Water distillation operates on the principle of physical phase separation, mimicking the natural hydrologic cycle of evaporation and condensation. The process begins by heating the source water until it converts entirely into steam. This vaporized water leaves behind virtually all dissolved solids and impurities, including minerals and heavy metals, that cannot turn into gas at the same temperature. The pure steam then travels into a separate cooling chamber where it cools and reverts to its liquid state, becoming highly purified water. What remains in the boiling chamber is a concentrated residue of everything that was initially dissolved in the water, including the fluoride compounds.
Quantifying Fluoride Removal
Distillation is one of the most effective household methods available for significantly reducing fluoride concentrations in water. Laboratory testing confirms that a properly functioning water distiller typically achieves fluoride removal rates greater than 99%. This high efficiency is a direct result of the fundamental difference in boiling points between water and fluoride. Fluoride exists as an ionic solid, which has an extremely high boiling point compared to water, meaning the fluoride ion cannot travel with the steam into the collection vessel.
Distillation Compared to Other Methods
When evaluating purification methods, distillation stands out for its comprehensive removal capabilities, though other technologies also target fluoride effectively.
Reverse Osmosis and Filtration
Reverse osmosis (RO) systems are another highly regarded option, working by forcing water through a semi-permeable membrane that blocks large ions like fluoride. RO systems typically remove a high percentage of fluoride, often ranging from 85% to 95%. Standard activated carbon filters, such as those found in pitchers or refrigerator units, are generally not designed to remove fluoride effectively. Specialized media, such as activated alumina or bone char carbon, must be used in dedicated filter systems to achieve significant fluoride reduction through adsorption.
Boiling Water
It is also worth noting that simply boiling water on a stovetop will not remove fluoride; instead, the evaporation of water actually concentrates the fluoride left behind in the remaining liquid.
The Mineral Content of Distilled Water
A secondary consequence of distillation’s high effectiveness is the removal of virtually all total dissolved solids, including minerals beneficial to human health. Because the process leaves behind everything that does not turn into steam, minerals such as calcium, magnesium, and potassium are eliminated along with the contaminants. This lack of mineral content can sometimes give distilled water a noticeably flat or bland taste compared to tap water. While the majority of the body’s mineral requirements are met through a balanced diet, some people choose to remineralize their distilled water for taste. It is safe to consume demineralized water as long as a consistent source of minerals is maintained through food.