Which liquid fluoride is commonly used in water fluoridation processes?

Hydrofluorosilicic acid is the commonly used liquid fluoride in water fluoridation processes due to its effective fluoridation capabilities and cost-effectiveness. This compound is a byproduct of phosphate fertilizer production, making it readily available and inexpensive for municipal water suppliers. When added to drinking water, hydrofluorosilicic acid dissociates to release fluoride ions, which help in reducing the incidence of dental caries (tooth decay) in the population.

Sodium fluoride and potassium fluoride can also be used for fluoridation; however, they are typically found in solid forms or used in different contexts. Calcium fluoride is less efficient when it comes to dissolving in water compared to hydrofluorosilicic acid, which affects its utility in large-scale water treatment settings. Thus, hydrofluorosilicic acid remains the preferred choice for many water utilities.