© 2025 American Dental Association l 35
Fluoridation Facts
16. Do home water treatment systems such as water filters, reverse
osmosis, and water softeners remove fluoride from drinking water?
Answer
Some types of home water treatment systems can reduce the fluoride levels in water supplies.
Individuals who drink water processed by home water treatment systems as their primary source
of water could be losing the decay-preventive effects of optimally fluoridated water available from
their community water supply.
Fact
There are many kinds of home water treatment systems, including reverse osmosis systems, distillation
units, water softeners, and water filters such as carafe filters, faucet filters, under-the-sink filters, and
whole-house filters. There has not been a large body of research regarding the extent to which these
treatment systems affect the fluoride content of optimally fluoridated water.176
However, it has been documented consistently that when working properly, almost all reverse
osmosis systems and distillation units remove most of the fluoride from the water supply.176-178
Studies regarding water softeners show clearly that the water-softening process does not
significantly change fluoride levels.179,180
With other types of water filters, the fluoride concentration remaining in the water depends on the
type and quality of the filter being used, the status of the filter, and the filter’s age. Most carbon filters
do not remove fluoride. However, some filters containing activated alumina can remove significant
amounts of fluoride. Additionally, some filters containing bone char also can remove significant
amounts of fluoride.178,181 Accordingly, each type of filter should be assessed individually.
Individuals who drink water processed by home water treatment systems as their primary source
of water could be losing the decay-preventive effects of optimally fluoridated water available from
their community water supply. Therefore, it might be necessary to contact the installer, distributor, or
manufacturer of the water treatment system or water filter in question to determine whether the item
removes fluoride. Information regarding the existing level of fluoride in a community’s public water
system can be obtained by asking a local dentist or contacting the local or state health department or
the local water supplier. If the consumer is using a private well, it is suggested that it be tested yearly
to determine the fluoride level.
Additional information on this topic can be found in this Section, Question 4.
Fluoridation Facts
16. Do home water treatment systems such as water filters, reverse
osmosis, and water softeners remove fluoride from drinking water?
Answer
Some types of home water treatment systems can reduce the fluoride levels in water supplies.
Individuals who drink water processed by home water treatment systems as their primary source
of water could be losing the decay-preventive effects of optimally fluoridated water available from
their community water supply.
Fact
There are many kinds of home water treatment systems, including reverse osmosis systems, distillation
units, water softeners, and water filters such as carafe filters, faucet filters, under-the-sink filters, and
whole-house filters. There has not been a large body of research regarding the extent to which these
treatment systems affect the fluoride content of optimally fluoridated water.176
However, it has been documented consistently that when working properly, almost all reverse
osmosis systems and distillation units remove most of the fluoride from the water supply.176-178
Studies regarding water softeners show clearly that the water-softening process does not
significantly change fluoride levels.179,180
With other types of water filters, the fluoride concentration remaining in the water depends on the
type and quality of the filter being used, the status of the filter, and the filter’s age. Most carbon filters
do not remove fluoride. However, some filters containing activated alumina can remove significant
amounts of fluoride. Additionally, some filters containing bone char also can remove significant
amounts of fluoride.178,181 Accordingly, each type of filter should be assessed individually.
Individuals who drink water processed by home water treatment systems as their primary source
of water could be losing the decay-preventive effects of optimally fluoridated water available from
their community water supply. Therefore, it might be necessary to contact the installer, distributor, or
manufacturer of the water treatment system or water filter in question to determine whether the item
removes fluoride. Information regarding the existing level of fluoride in a community’s public water
system can be obtained by asking a local dentist or contacting the local or state health department or
the local water supplier. If the consumer is using a private well, it is suggested that it be tested yearly
to determine the fluoride level.
Additional information on this topic can be found in this Section, Question 4.
