What Type of Fluoride Is Used in Drinking Water?
Quick answer: Australian water authorities typically add fluoride to drinking water as fluorosilicic acid (also called hydrofluorosilicic acid) or sodium fluoride. The concentration is tightly regulated -- in Victoria, for example, the maximum level is 1 milligram per litre (mg/L), with an optimum target of 0.9 mg/L. Natural fluoride is also present in many source waters before any addition takes place.
Why fluoride is added to drinking water in Australia
Fluoride has been added to Australian drinking water supplies for decades. As health.vic.gov.au notes, other parts of Australia have had fluoridated drinking water for more than 50 years. The practice is intended to maintain fluoride at a level considered beneficial for dental health by public health authorities, and it is governed by legislation and national guidelines rather than left to individual water utilities to decide.
In Victoria, the process is governed by the Health (Fluoridation) Act 1973, which regulates the fluoridation of drinking water supplies and sets the concentration value that utilities must achieve, as Yarra Valley Water explains. Understanding what compound is actually added -- and at what level -- is a reasonable question for any household that wants to know more about what is in their tap water.
What type of fluoride compound is used?
The fluoride added to drinking water is not a single universal substance -- water authorities use one of several approved fluoride compounds, most commonly fluorosilicic acid (also written as hydrofluorosilicic acid, H2SiF6) or sodium fluoride (NaF). Sodium fluorosilicate is also used in some systems. The choice of compound depends on the scale of the treatment plant, local supply logistics, and the dosing equipment available.
Fluorosilicic acid is the most widely used compound in large municipal systems because it is a liquid and easier to dose accurately at scale. Sodium fluoride is a dry powder or granule that is dissolved before dosing, and it is more common in smaller systems. All approved compounds dissociate in water to release fluoride ions -- the same ion that occurs naturally in groundwater and surface water -- so the compound used does not change the form of fluoride that reaches your tap.
It is also worth noting that fluoride is not always added artificially. As Yarra Valley Water states, surface water and many bore waters used for drinking water can contain concentrations of natural fluoride up to one milligram per litre (mg/L). Where natural levels are already adequate, no addition may be needed.
What concentration of fluoride is in Australian drinking water?
Fluoride concentrations in Australian drinking water are set and monitored by state health authorities and water utilities. The levels are low -- far lower than the fluoride in everyday dental products.
In Victoria, health.vic.gov.au states that the maximum level of fluoride in drinking water is 1 milligram per litre (mg/L), or 1 part per million (ppm), as recommended by the World Health Organization. For context, the same source notes that children's toothpaste contains 400 to 500 ppm of fluoride, and regular toothpaste contains 1,000 ppm -- many times higher than the level in drinking water.
More specifically, Yarra Valley Water states that the acceptable fluoride concentration range for Melbourne is between 0.7 and 1.2 mg/L, with the optimum concentration being 0.9 mg/L. The amount added is less than one milligram per litre of water -- proportionally equivalent, as Yarra Valley Water puts it, to one grain of sugar in a cup of water.
How is fluoridation regulated in Australia?
Fluoridation is not left to individual utilities to manage without oversight. In Victoria, the Health (Fluoridation) Act 1973 regulates the fluoridation of drinking water supplies, and the fluoridation process adjusts the concentration of fluoride to a value set by that Act, as Yarra Valley Water explains. The amount of fluoride in the water is measured and added in accordance with guidelines set by the 1987 National Health and Medical Research Council and the Australian Water Resources Council.
In New South Wales, NSW Health oversees the fluoridation of drinking water, including technical applications for new or upgraded fluoridation systems and notifications of any dosing incidents or disruptions to fluoridation. Each state and territory has its own legislative framework, but all operate within national guidelines.
For Victorian households wanting to know which suburbs receive fluoridated water, Yarra Valley Water notes that a complete list is available on the Department of Health and Human Services website.
Is fluoride at these levels considered safe?
This article does not provide medical advice, and any questions about individual health should be directed to a qualified health professional. What the relevant authorities state is this: health.vic.gov.au reports that academic clinicians from the Department of Allergy, Immunology and Respiratory Medicine at Melbourne's Alfred Hospital have stated there is no clinical or scientific evidence that fluoridation affects allergies or immunities at the optimal 1 mg/L level. Those clinicians noted that over 25 years, whether in Melbourne or in the UK, they had not seen a patient with any respiratory symptoms or allergy-like symptoms that could be attributed to fluoride at 1 ppm as found in fluoridated water.
Guidance on fluoride use in Australia has also been developed by professional bodies. As health.vic.gov.au notes, in June 2006 the Australian Research Centre for Population Oral Health (ARCPOH) published guidelines for Australian fluoride use. Regulatory frameworks and professional guidelines are the appropriate place to look for authoritative positions on safety; this article simply explains what is in the water and at what level.
Key takeaways
- The fluoride compounds most commonly used in Australian drinking water are fluorosilicic acid and sodium fluoride; all approved compounds release the same fluoride ion once dissolved.
- Natural fluoride is already present in many source waters at up to 1 mg/L before any addition is made.
- In Victoria, the maximum fluoride level in drinking water is 1 mg/L (1 ppm), with an optimum target of 0.9 mg/L for Melbourne.
- Fluoridation is governed by state legislation and national guidelines, with ongoing monitoring and reporting requirements.
- The fluoride concentration in drinking water is far lower than in everyday dental products such as toothpaste.
Frequently Asked Questions
What is the most common fluoride compound added to Australian tap water?
Fluorosilicic acid (hydrofluorosilicic acid) is the most widely used compound in large municipal water systems because it is a liquid that is straightforward to dose accurately. Sodium fluoride and sodium fluorosilicate are also used, particularly in smaller systems. Once dissolved in water, all of these compounds release the same fluoride ion.
Is the fluoride in tap water the same as the fluoride in toothpaste?
Both contain fluoride ions, but the concentrations are very different. As health.vic.gov.au notes, children's toothpaste contains 400 to 500 ppm of fluoride and regular toothpaste contains 1,000 ppm, compared to a maximum of 1 mg/L (1 ppm) in Victorian drinking water.
Does all Australian tap water contain added fluoride?
Not necessarily. Fluoridation coverage varies by state, territory, and local area. Some regions rely on naturally occurring fluoride in source water, while others have no fluoridation program. Your local water authority or state health department can confirm whether your supply is fluoridated and at what level.
How is the fluoride level in drinking water monitored?
Water utilities are required to measure and adjust fluoride concentrations in accordance with state legislation and national guidelines. In Victoria, the Health (Fluoridation) Act 1973 sets the framework, and utilities such as Yarra Valley Water operate within those requirements. In NSW, NSW Health requires notification of any dosing incidents or disruptions via the Drinking Water Data Portal.
Can fluoride be reduced in drinking water at home?
Standard tap filters and jug filters are generally designed to address chlorine, sediment, and taste and odour. The HydroX Electric Water Filter is designed to reduce up to 98% of fluoride. Actual reduction depends on your water conditions and how the filter is used.
Sources
- Fluoridation | Yarra Valley Water
- Water fluoridation in Victoria | health.vic.gov.au
- Fluoridation of drinking water | NSW Health
