© 2025 American Dental Association l 61
Fluoridation Facts
32. Does drinking water fluoridated at the recommended levels cause or
accelerate the growth of cancer?
Answer
No. According to the best available scientific evidence, there is no association between cancer rates
in humans and drinking water that is fluoridated at the recommended levels.
Fact
Since community water fluoridation was introduced in 1945, more than 50 epidemiologic studies
in different populations and at different times have failed to demonstrate an association between
fluoridation and the risk of cancer.182 Studies have been conducted in the United States,278-283
Japan,284 the United Kingdom,285-287 Canada,288 and Australia.289 In addition, over the years, a number
of independent bodies from around the world have conducted extensive reviews of the scientific
literature and concluded that there is no relationship between fluoridation and cancer.182,183,185,223,290
At the beginning of the Safety Section in Question 17, a number of recent reviews are listed that have
also concluded there is no relationship between fluoridation and cancer.34,35,37-41 The best available
science clearly indicates there is no association between fluoridation and cancer.
The best available science clearly indicates there is no association between
fluoridation and cancer.
Many of the questions about a possible association between fluoride and cancer center around
a form of bone cancer called osteosarcoma. This topic is covered in Question 33.
California Office of Environmental Health Hazard Assessment
In October 2011, the California Office of Environmental Health Hazard Assessment (OEHHA)
through its Carcinogen Identification Committee (CIC) determined that fluoride does not cause
cancer. The review was part of California’s Proposition 65 listing process.291 Proposition 65 was
enacted in 1986 with the intent to protect California citizens and the state’s drinking water sources
from chemicals known to cause cancer, birth defects, or other reproductive harm and to inform
citizens about exposure to such chemicals. It requires the governor to publish, at least annually, a list
of chemicals known to the state to cause cancer or reproductive toxicity. The OEHHA administers
meetings of the CIC and the list of items to be reviewed through the Proposition 65 process.
On May 29, 2009, fluoride was selected by OEHHA for review by the CIC. Due to its widespread nature,
fluoride was identified as one of five high-priority chemicals to be evaluated. A public comment period
followed. On July 8, 2011, as the next step in the Proposition 65 process, the CIC released a hazard
identification document, Evidence on the Carcinogenicity of Fluoride and its Salts. It was used by the CIC
in its deliberations on whether fluoride should be listed as a carcinogen under Proposition 65. A second
public comment period followed. At a public meeting on October 12, 2011, the CIC heard additional
testimony and then voted on the question, “Do you believe that it has been clearly shown, through
scientifically valid testing according to generally accepted principles, that fluoride causes cancer?”
The CIC’s vote was unanimous (6-0) that fluoride had not been clearly shown to cause cancer.292
Fluoridation Facts
32. Does drinking water fluoridated at the recommended levels cause or
accelerate the growth of cancer?
Answer
No. According to the best available scientific evidence, there is no association between cancer rates
in humans and drinking water that is fluoridated at the recommended levels.
Fact
Since community water fluoridation was introduced in 1945, more than 50 epidemiologic studies
in different populations and at different times have failed to demonstrate an association between
fluoridation and the risk of cancer.182 Studies have been conducted in the United States,278-283
Japan,284 the United Kingdom,285-287 Canada,288 and Australia.289 In addition, over the years, a number
of independent bodies from around the world have conducted extensive reviews of the scientific
literature and concluded that there is no relationship between fluoridation and cancer.182,183,185,223,290
At the beginning of the Safety Section in Question 17, a number of recent reviews are listed that have
also concluded there is no relationship between fluoridation and cancer.34,35,37-41 The best available
science clearly indicates there is no association between fluoridation and cancer.
The best available science clearly indicates there is no association between
fluoridation and cancer.
Many of the questions about a possible association between fluoride and cancer center around
a form of bone cancer called osteosarcoma. This topic is covered in Question 33.
California Office of Environmental Health Hazard Assessment
In October 2011, the California Office of Environmental Health Hazard Assessment (OEHHA)
through its Carcinogen Identification Committee (CIC) determined that fluoride does not cause
cancer. The review was part of California’s Proposition 65 listing process.291 Proposition 65 was
enacted in 1986 with the intent to protect California citizens and the state’s drinking water sources
from chemicals known to cause cancer, birth defects, or other reproductive harm and to inform
citizens about exposure to such chemicals. It requires the governor to publish, at least annually, a list
of chemicals known to the state to cause cancer or reproductive toxicity. The OEHHA administers
meetings of the CIC and the list of items to be reviewed through the Proposition 65 process.
On May 29, 2009, fluoride was selected by OEHHA for review by the CIC. Due to its widespread nature,
fluoride was identified as one of five high-priority chemicals to be evaluated. A public comment period
followed. On July 8, 2011, as the next step in the Proposition 65 process, the CIC released a hazard
identification document, Evidence on the Carcinogenicity of Fluoride and its Salts. It was used by the CIC
in its deliberations on whether fluoride should be listed as a carcinogen under Proposition 65. A second
public comment period followed. At a public meeting on October 12, 2011, the CIC heard additional
testimony and then voted on the question, “Do you believe that it has been clearly shown, through
scientifically valid testing according to generally accepted principles, that fluoride causes cancer?”
The CIC’s vote was unanimous (6-0) that fluoride had not been clearly shown to cause cancer.292
