© 2025 American Dental Association l 13
Fluoridation Facts
5. What additives are used to fluoridate water supplies in the
United States?
Answer
Sodium fluoride, sodium fluorosilicate, and fluorosilicic acid are the three additives approved for
use in community water fluoridation in the United States. Sodium fluorosilicate and fluorosilicic
acid are sometimes referred to as silicofluoride additives.
Fact
The three primary additives used to fluoridate water in the United States are: (1) sodium fluoride, which
is a white, odorless material available either as a powder or crystals (2) sodium fluorosilicate, which is
a white or yellow-white, odorless crystalline material and (3) fluorosilicic acid, which is a white or
straw-colored liquid.36
Water fluoridation began in the United States in 1945 with the use of sodium fluoride. The use of
silicofluorides began in 1946, and by 1951, they were the most commonly used additives.88 First used in
the late 1940s, fluorosilicic acid is currently the most commonly used additive to fluoridate communities
in the United States.89
To ensure the public’s safety, additives should meet safety standards for water treatment in the
United States, regardless of where the additives are manufactured.36 Specifically, additives used in
water fluoridation should meet standards of the American Water Works Association (AWWA). Fluoride
additives, like any other water additive, should also meet standards set by NSF (formerly the National
Sanitation Foundation) and the American National Standards Institute (ANSI).90 In the United States,
the authority to regulate products for use in drinking water, including additives used to fluoridate
community water systems, rests with individual states. In 2020, NSF reported that 49 states had
adopted the NSF/ANSI Standard 60, which specifies the product quality, with validation supplied by
independent certification entities.90
Additional information on the topic of fluoride additives can be found in the Fluoridation Practice
section of this publication and at the CDC’s website, “Fluoridation Engineering and Operations.”91
To ensure the public’s safety, additives should meet safety standards for water
treatment in the United States, regardless of where they are manufactured.
Fluoridation Facts
5. What additives are used to fluoridate water supplies in the
United States?
Answer
Sodium fluoride, sodium fluorosilicate, and fluorosilicic acid are the three additives approved for
use in community water fluoridation in the United States. Sodium fluorosilicate and fluorosilicic
acid are sometimes referred to as silicofluoride additives.
Fact
The three primary additives used to fluoridate water in the United States are: (1) sodium fluoride, which
is a white, odorless material available either as a powder or crystals (2) sodium fluorosilicate, which is
a white or yellow-white, odorless crystalline material and (3) fluorosilicic acid, which is a white or
straw-colored liquid.36
Water fluoridation began in the United States in 1945 with the use of sodium fluoride. The use of
silicofluorides began in 1946, and by 1951, they were the most commonly used additives.88 First used in
the late 1940s, fluorosilicic acid is currently the most commonly used additive to fluoridate communities
in the United States.89
To ensure the public’s safety, additives should meet safety standards for water treatment in the
United States, regardless of where the additives are manufactured.36 Specifically, additives used in
water fluoridation should meet standards of the American Water Works Association (AWWA). Fluoride
additives, like any other water additive, should also meet standards set by NSF (formerly the National
Sanitation Foundation) and the American National Standards Institute (ANSI).90 In the United States,
the authority to regulate products for use in drinking water, including additives used to fluoridate
community water systems, rests with individual states. In 2020, NSF reported that 49 states had
adopted the NSF/ANSI Standard 60, which specifies the product quality, with validation supplied by
independent certification entities.90
Additional information on the topic of fluoride additives can be found in the Fluoridation Practice
section of this publication and at the CDC’s website, “Fluoridation Engineering and Operations.”91
To ensure the public’s safety, additives should meet safety standards for water
treatment in the United States, regardless of where they are manufactured.
