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Section 3: Fluoridation Practice
54. Does fluoride at levels used in fluoridation corrode water pipes?
Answer
No. Allegations that fluoridation causes corrosion of water pipes are not supported by the best
available scientific evidence.
Fact
The process of adding fluoride to water has minimal impact on the acidity or pH of drinking water, and
therefore will not corrode water pipes. Corrosion of drinking water pipes is related primarily to induced
electrical current between dissimilar metals. Other contributing factors include the dissolved oxygen
concentration, water temperature, acidity/alkalinity (pH), hardness, salt concentration, hydrogen
sulfide content, and the presence of certain bacteria. Under some water quality conditions, a small
increase in the acidity of drinking water that is already slightly acidic may be observed after treatment
with alum, chlorine, fluorosilicic acid, or sodium fluorosilicate. In such cases, further water treatment
to adjust the pH to neutralize the acidity for corrosion control in water distribution systems is standard
procedure in water plants.343
The process of adding fluoride to water has minimal impact on the acidity or pH
of drinking water, and therefore will not corrode water pipes.
Note that the Water Quality Report or Consumer Confidence Report that all water systems must make
available to customers on a yearly basis may list the pH of the system’s finished water.386 Control of
neutral pH (7.0) is essential as part of corrosion control requirements. Water facilities typically maintain
a pH of between 7.0 and 8.0 as good practice so that the water leaving the plant is slightly alkaline and
non-acidic.344
Use of corrosion control measures by water utilities is a standard practice to ensure the system
meets the EPA requirements under the lead/copper rule.343,344,386 Those actions would ensure that
any potential corrosion by water additives is identified and neutralized to remain in compliance with
regulatory requirements.
Section 3: Fluoridation Practice
54. Does fluoride at levels used in fluoridation corrode water pipes?
Answer
No. Allegations that fluoridation causes corrosion of water pipes are not supported by the best
available scientific evidence.
Fact
The process of adding fluoride to water has minimal impact on the acidity or pH of drinking water, and
therefore will not corrode water pipes. Corrosion of drinking water pipes is related primarily to induced
electrical current between dissimilar metals. Other contributing factors include the dissolved oxygen
concentration, water temperature, acidity/alkalinity (pH), hardness, salt concentration, hydrogen
sulfide content, and the presence of certain bacteria. Under some water quality conditions, a small
increase in the acidity of drinking water that is already slightly acidic may be observed after treatment
with alum, chlorine, fluorosilicic acid, or sodium fluorosilicate. In such cases, further water treatment
to adjust the pH to neutralize the acidity for corrosion control in water distribution systems is standard
procedure in water plants.343
The process of adding fluoride to water has minimal impact on the acidity or pH
of drinking water, and therefore will not corrode water pipes.
Note that the Water Quality Report or Consumer Confidence Report that all water systems must make
available to customers on a yearly basis may list the pH of the system’s finished water.386 Control of
neutral pH (7.0) is essential as part of corrosion control requirements. Water facilities typically maintain
a pH of between 7.0 and 8.0 as good practice so that the water leaving the plant is slightly alkaline and
non-acidic.344
Use of corrosion control measures by water utilities is a standard practice to ensure the system
meets the EPA requirements under the lead/copper rule.343,344,386 Those actions would ensure that
any potential corrosion by water additives is identified and neutralized to remain in compliance with
regulatory requirements.
