© 2025 American Dental Association l 67
Fluoridation Facts
There are no confirmed cases of allergy to fluoride or of any positive skin testing in human or animal
models.312 A committee of the National Academy of Sciences evaluated clinical reports of possible
allergic responses to fluoride in 1977 and stated, “The reservation in accepting (claims of allergic
reaction) at face value is the lack of similar reports in much larger numbers of people who have been
exposed to considerably more fluoride than was involved in the original observations.”24 The WHO
also judged these cases to represent “a variety of unrelated conditions” and found no evidence of
allergic reactions to fluoride.313, 314
38. Is fluoride, as provided by community water fluoridation,
a genetic hazard?
Answer
No. The best available scientific evidence indicates that drinking water fluoridated at the
recommended levels is not a genetic hazard.
Fact
Chromosomes are structures that carry our genetic information. The genetic information on our
chromosomes is organized into genes, which are made up of specific DNA sequences. Individual genes
give our body information on how to grow, develop, and function. Many studies have examined the
possible effects of fluoride on chromosome damage, which is also referred to as genotoxicity.
In 1993, the NRC issued a report25 that supported the conclusion that drinking optimally fluoridated
water is not a genetic hazard. In a statement summarizing its research,25 the NRC stated:
“In vitro data indicate that:
1. The genotoxicity of fluoride is limited primarily to doses much higher
than those to which humans are exposed.
2. Even at high doses, genotoxic effects are not always observed.
3. The preponderance of the genotoxic effects reported are of types
that probably are of no or negligible genetic significance.”25
The lowest dose of fluoride reported to cause chromosomal changes in mammalian cells was approximately
170 times that normally found in human cells in areas where drinking water was fluoridated at 1.0 mg/L,
which indicates a large margin of safety.25 (Note that this would be 242 times the current fluoridation
level of 0.7 mg/L.)
In its subsequent 2006 report,26 the NRC stated that, after reviewing the evidence available since its
1993 report, the weight of evidence from studies on rodents indicated a very low probability that
fluoride presents a risk of genetic mutation for humans.26
In addition, the 2006 NRC report26 indicated that the results of human studies related to fluoride
and its effect on genotoxicity since its 1993 report are inconsistent and do not strongly indicate
the presence or absence of genotoxic potential for fluoride.
A systematic review published in 2024315 concluded “...that fluoride is not a genotoxic agent since
the majority of studies demonstrated negative findings.”
Fluoridation Facts
There are no confirmed cases of allergy to fluoride or of any positive skin testing in human or animal
models.312 A committee of the National Academy of Sciences evaluated clinical reports of possible
allergic responses to fluoride in 1977 and stated, “The reservation in accepting (claims of allergic
reaction) at face value is the lack of similar reports in much larger numbers of people who have been
exposed to considerably more fluoride than was involved in the original observations.”24 The WHO
also judged these cases to represent “a variety of unrelated conditions” and found no evidence of
allergic reactions to fluoride.313, 314
38. Is fluoride, as provided by community water fluoridation,
a genetic hazard?
Answer
No. The best available scientific evidence indicates that drinking water fluoridated at the
recommended levels is not a genetic hazard.
Fact
Chromosomes are structures that carry our genetic information. The genetic information on our
chromosomes is organized into genes, which are made up of specific DNA sequences. Individual genes
give our body information on how to grow, develop, and function. Many studies have examined the
possible effects of fluoride on chromosome damage, which is also referred to as genotoxicity.
In 1993, the NRC issued a report25 that supported the conclusion that drinking optimally fluoridated
water is not a genetic hazard. In a statement summarizing its research,25 the NRC stated:
“In vitro data indicate that:
1. The genotoxicity of fluoride is limited primarily to doses much higher
than those to which humans are exposed.
2. Even at high doses, genotoxic effects are not always observed.
3. The preponderance of the genotoxic effects reported are of types
that probably are of no or negligible genetic significance.”25
The lowest dose of fluoride reported to cause chromosomal changes in mammalian cells was approximately
170 times that normally found in human cells in areas where drinking water was fluoridated at 1.0 mg/L,
which indicates a large margin of safety.25 (Note that this would be 242 times the current fluoridation
level of 0.7 mg/L.)
In its subsequent 2006 report,26 the NRC stated that, after reviewing the evidence available since its
1993 report, the weight of evidence from studies on rodents indicated a very low probability that
fluoride presents a risk of genetic mutation for humans.26
In addition, the 2006 NRC report26 indicated that the results of human studies related to fluoride
and its effect on genotoxicity since its 1993 report are inconsistent and do not strongly indicate
the presence or absence of genotoxic potential for fluoride.
A systematic review published in 2024315 concluded “...that fluoride is not a genotoxic agent since
the majority of studies demonstrated negative findings.”
