Fluoride is one of the biggest talking points in the water industry at the moment. John Chaumont figures out how it works and what it means for the plumbing industry.

Of all the chemical additives commonly found in the human diet, fluoride is currently one of the most polarising, misunderstood and controversial.

Depending on dosage, fluoride intake has both positive and negative impacts on our health.

Depending on location, water fluoridation is either mandated or banned by either federal, state or local government.

Depending on who you talk to, fluoride should be added or removed from our drinking water supply.

And depending on what you read, fluoridated water is either “one of the ten greatest public health achievements of the 20th century (according to the CDC) or “industrial waste” according to United States Secretary of Health and Human Services, Robert F. Kennedy.

Considered a preventative medicine, fluoride’s primary purpose is to reduce tooth decay and disease (known as the dental term ‘caries’) within a country, state or regional population.

Most of us have a limited understanding of the reason behind water fluoridation, and if asked, would respond with something like: It’s good for my teeth.

Many support this form of ‘mass preventative medication’, while some have dived down the bottomless fluoride rabbit-hole, finding a myriad of claims, concerns and questionable theories. While many more are impartial, or simply don’t care: We drink up and take our medicine.

So, what is fluoride?

A naturally occurring mineral found practically everywhere (soil, rocks, food, plants, animals, rivers, oceans, air), fluoride can be found naturally at varying levels, present in the drinking water supply for communities that rely on bores and wells.

Fluoride is also artificially added (most commonly in the form of sodium fluoride (NaF) or hydrofluorosilicic acid to municipal drinking water supplies all over the world. This is called ‘water fluoridation’.

While there is no direct official threshold of fluoride content in water at which it can be defined as ‘fluoridated’, the World Health Organisation’s (WHO) 2022 Fact Sheet on Fluoride states that the minimum concentration required to provide protection is approximately 0.5mg/L, and that “the protective effects of fluoride increase with concentration up to about 2mg/L”.

Water fluoridation globally

Water fluoridation was first conducted as a study for the first time in history in 1945, Michigan, USA. Australia followed suit by 1953, starting with Beaconsfield, Tasmania, then Yass, NSW, in 1956. Since then, most major Australian cities have had fluoridated water since the 1970s.

Surprisingly, fluoridated water is available (from both naturally occurring and artificially fluoridated sources) for approximately 425 million people worldwide, only 5.18% of the global population.

Although fluoridated water is available to such a small number of the global population, 89% of Australians have access to fluoridated water, 56% in New Zealand, 63% in the USA, and only 10% in the UK.

Isn’t fluoridated water good for us?

Fluoride has both good and bad effects on our bodies, but the margin for error between is slim.

The good is that according to the National Health and Medical Research Council (NHMRC), fluoride reduces dental decay by 26-44% in children and 27% in adults. Fluoride delays demineralisation and enhances remineralisation of the enamel on our teeth.

Fluoridated water stays good for us, so long as its concentration is below the threshold range of 1.5mg/L. This is good news, particularly as the most recent data shows Australia spent $11.1 billion on dental services in 2021–22.

The not-so-good is that water with fluoride levels above the 1.5mg/L threshold poses several concerns to many, including dental and skeletal fluorosis, increased risk of bone fractures, plus negative effects on the thyroid system and reproductive system. The main issue is exceeding recommended daily intakes of fluoride, which differ between age brackets.

The WHO’s 2022 Fact Sheet on Fluoride states that: “Fluoride can also have an adverse effect on tooth enamel and may give rise to mild dental fluorosis (prevalence: 12–33%) at drinking-water concentrations between 0.9 and 1.2mg/L, depending on drinking water intake and exposure to fluoride from other sources.”

This may be mildly concerning to some, given the 1.5mg/L recommendation from the WHO and current concentrations in Australian water supplies.

More recently, the US Government’s National Toxicology Program (NTP) conducted a study and concluded that water with fluoride levels >1.5mg/L has been associated with a lower I.Q. in children. This was used in the class action lawsuit against the U.S Environmental Protection Agency (EPA), more on this later.

Lawsuits from both ends of the spectrum

Quite ironically, in 2024, fluoride was the subject of two major class-action lawsuits in the USA.

One lawsuit was against the EPA for adding fluoride to the water supply (the court handed down a decision in late 2024 that the EPA must provide a regulatory response to the ‘unreasonable risk’ associated with harms from fluoridated water).

The other lawsuit was against the City of Buffalo, New York, for failing to add fluoride (the claim was that the City violated its citizens’ constitutional rights to a healthy environment by “depriving Buffalo’s residents of therapeutic fluoridated drinking water.”

Isn’t water fluoridation recommended by everyone?

Water fluoridation is recommended by the WHO, NHMRC, Australian Medical Association (AMA) and the Australian Dental Association (ADA).

The US Centre for Disease Control (CDC) currently supports water fluoridation in its health policy; however, recent announcements suggest this will likely be paused while investigations into safety are conducted with the EPA and the Department of Human Health Services (HHS).

Fluoride legislation: A confusing mix of governments, mandates and prohibitions

Water fluoridation is mandatory at a nationwide level in Ireland. In New Zealand, nationwide water fluoridation is not mandatory but may be required if directed by the federal Health Minister.

Countries such as Australia, the UK and the USA either mandate or ban fluoride through state legislation, depending on the state.

Take Queensland, for example, whose public health policy on the matter has been dubbed a “political headache”. The Queensland Government, via the Water Fluoridation Act 2008 Section 7 (1) and (3), delegated decision-making power to local governments (LGAs), giving them the ability to add or forgo water fluoridation.

As of February 2025, QLD Health data shows that while 72% of the population receives fluoridated drinking water, a staggering 53 out of 75 LGAs do not.

Meanwhile, in the USA, water fluoridation is now prohibited in the states of Florida and Utah, and the US Health Secretary has announced plans to direct the Centre for Disease Control (CDC) to cease recommending water fluoridation. It is thought that this bill will prompt other US states, and potentially other water utilities around the world, to follow suit.

A 2018 report from Dublin City University found that other countries, such as Finland, Germany, the Netherlands and Switzerland, previously practised water fluoridation, but later ceased the activity. The same report showed that many other countries, including Austria, Denmark, France, Greece, Italy and Norway, have never practised water fluoridation to begin with.

In the report, each country gave various reasons, the most common being that alternative sources of fluoride are readily available elsewhere, and concerns over the violation of personal rights.

Health concerns over fluoride were the least reported reason.

Water fluoridation is determined by various acts and regulations in each Australian State (except South Australia, which has no such act!).

Recommended daily intake for fluoride

According to Dietary Intake Guidelines from the NHMRC, the recommended adequate intake (AI) and upper level of intake (UL) is as follows.

Table: 2 Recommended daily intake for fluoride

The WHO and Australian Drinking Water Guidelines (ADWG) advise that drinking water should not contain fluoride exceeding 1.5mg/L, with the ADWG further recommending a dosage between 0.6 – 1.1mg/L The lower dosage in this range applies to areas with a hotter climate, which would naturally have a higher average consumption of water.

Fluoride in our diet

Fluoride is ingested from food, water (fluoridated & unfluoridated), fluoridated toothpaste and some supplements. In food, higher concentrations are found in ultra-processed foods, fruit juice, chicken and rice. The highest levels of fluoride are found in non-herbal tea (standard black or green tea) as tea plants absorb high levels of fluoride and other toxins from soil.

Am I getting too much fluoride?

Realistically, as an adult, no.

Using the NHMRC recommended intake limits for an adult of 4mg/day adequate intake (AI), 10mg/day upper levels (UL) and average fluoride levels in Sydney of 1mg/L as of 26/8/2025. It’s feasible that the average adult exceeds the recommended AI levels, while falling safely beneath the UL of intake.

This is, of course, dependent on body weight, type of toothpaste used, diet, water intake and so on.

What about children?

Regarding children, the answer is a little less than certain. For example, using the NHMRC recommended intake limits for a child of 1.1mg/day AI, 4.4mg/day UL – the average eight-year-old probably exceeds the recommended adequate intake (AI) levels, and possibly their upper levels (UL) of intake too. Particularly if the child is active and drinks a lot of water, uses fluoridated toothpaste, eats foods that contain higher levels of fluoride and has an inclination for tea (for sophisticated children).

What does this mean for the plumbing industry?

Quite frankly, not much. Of late, there has been heightened interest amongst younger generations in alternative perspectives on personal health as a whole, not simply trusting the status quo. This has led many to perform self-research on the topic of water filtration for domestic homes, which will naturally result in an uptick in plumbers encountering clients opting for a range of under-sink or whole-house filters to be installed in the home.

Due to increasing interest in water filters that remove or reduce fluoride, plumbers should note that while there are many under-sink and whole-of-house filters currently on the market, not all of them remove fluoride from tap water. The most effective way to remove fluoride from drinking water is by reverse osmosis, distillation or activated alumina.

Presently, there are several options on the Australian market. For example:

• Alkaway Australia offer a whole-of-house three-stage filter which drastically reduces chlorine and chloramines, PFAS and includes an activated alumina filter for fluoride.
• Puretec Australia offer under-sink, reverse osmosis filter systems and cartridges for reducing fluoride.
• For renters or clients who are unsure, plumbers can suggest Waters Co Australia, who offer an above-sink water filter, which could be trialled before a permanent water filter installation.

Conclusion

To state the obvious – Plumbers are not medical professionals! However, when discussing fluoride with clients, plumbers should take care to understand that water fluoridation is not a simple topic, and that there is a large amount of conflicting information online.

It is the plumbers’ job to be informed of arguments made on both sides in order to give sensible, sound advice and able to point clients to the right resources and products.