The Dáil has been told that there are no risks to public health from fluoride in tap water.
TDs are debating a bill from Sinn Féin which would ban the practice of adding fluoride to public water supplies.
Responding to concerns about the effect of fluoride on the health of young children, Alex White, the Minister of State for Primary Care, said no such danger exists.
"The Food Safety Authority of Ireland and the expert body also advised that there's no significant evidence of any adverse effects to the health of infants consuming infant formula made with fluoridated tap water," he said.
"Fluoride concentrations in Irish tap water pose no known medical problems - either for infants or the population in general."
Sinn Féin, however, claims that the chemical is dangerous at high doses and that people get enough fluoride from modern toothpastes.
"All of us are being slowly poisoned by the use of fluoride in the water supply," said Sinn Féin TD Brian Stanley.
"It's an issue that affects the vast majority of households … 50 years of it has been enough."