The future of a suit challenging the EPA’s stance that fluoride in drinking water doesn’t pose unreasonable risks to young children is the focus of dueling motions before a federal judge in San Francisco Nov. 15.

The outcome could determine whether the case proceeds to trial in February, where a court would hear a debate over the risks and benefits of what has been common practice in the U.S. for more than half a century: municipalities adding fluoride to drinking water for dental health.

A coalition of health advocates in November 2016 petitioned the Environmental Protection Agency to begin the process of making a rule to ban fluoridation chemicals in drinking water. The EPA denied the petition, and the groups sued.

The groups argue that under EPA’s longstanding risk assessment policies, fluoridation chemicals pose an “unacceptable risk” to human health when added to drinking water.

“EPA’s current ‘safe’ drinking water standard for fluoride is so high that its own scientists sought to file an amicus brief to support an environmental organization’s challenge to it,” the coalition, led by Food & Water Watch, said in a court motion.

Trial Looming

The EPA wants the case stopped now, before it gets to trial, and argues that health groups failed to offer evidence demonstrating an unreasonable risk of injury from exposure to fluoridation chemicals in concentrations up to 0.7 milligrams per liter.

The health advocates want the judge to immediately rule that fluoride in drinking water poses an unreasonable risk, that would trigger the need for an EPA regulation of that use of fluoride.

Judge Edward M. Chen of the U.S. District Court for the Northern District of California will hear arguments Nov. 15 on the agency and coalition dualing motions. If EPA and the health advocates lose in their bids for summary judgment, a trial is scheduled to start Feb. 3.


The case is being watched in part for what it could portend for future efforts to regulate chemicals under the Toxic Substances Control Act, said Erik C. Baptist, a partner with Wiley Rein LLP.

If the case goes to trial and a court eventually concludes that adding fluoride to drinking water poses an unreasonable risk, the health advocates will say the EPA must prohibit that use of fluoride.

If that scenario plays out, other groups may see filing a petition with EPA requesting a new rule as a quicker way to get a chemical regulated or banned than the risk evaluation and risk management process laid out in the statute, said Baptist, former deputy assistant administrator for law and policy in the Office of Chemical Safety and Pollution Prevention.

Chemical Benefits

The EPA says the health groups haven’t made the case that flouride in drinking water poses an unreasonable risk.

But the health advocates point to a 2017 federal study that found increased levels of fetal fluoride exposure linked to lower childhood IQ. And a Canadian study reported in August that fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years.

A September 2019 draft report by the National Toxicology Program, which examined the Canadian study and others, said that human studies show higher fluoride exposure is associated with decreased IQ or other cognitive impairments in children. However, it added that studies with exposures in the range typically found in U.S. tap water showed effects on cognitive neurodevelopment were inconsistent, and therefore unclear.

The EPA also maintains that a chemical’s health benefits can reduce or possibly cancel out its risks.

For example, certain amounts of some metals provide essential health benefits while excessive exposures can be harmful. An EPA risk assessment would have to consider risks and benefits, and the doses that trigger one or the other, the EPA said.

According to Centers for Disease Control statistics, 211,393,167 people in the U.S., or 66.3% of the population, had fluoridated tap water in 2014.

The case is Food & Water Watch v. EPA, N.D. Cal., No. 3:17-cv-02162.