Fluoride facts for Western Australia
In Western Australia the following compounds containing fluoride are added to drinking water supplies:
- fluorosilicic acid (a compound of fluorine, hydrogen and silicon). This is the most common method of adding fluoride to drinking water supplies in WA. A very small amount of fluorosilicic acid is added at the treatment plant as a liquid, where it dissolves to release fluoride ion.
- sodium fluoride (a compound of fluorine and sodium). Sodium fluoride is delivered as a powder which is added to the drinking water supply in small quantities at the treatment plant, where it dissolves to release fluoride ion. Sodium fluoride is used in some of the smaller public drinking water supplies in WA.
- In all cases the compounds containing fluoride that are added dissociate (break down) into their components well before the water leaves the treatment plant.
Where does the fluoride that is added to drinking water come from?
- Fluorosilicic acid is sourced as a by-product from superphosphate production. Phosphate rock and sulphuric acid are the main raw materials used to make fluorosilicic acid. This is the most common way of making fluoride found around the world. The fluorosilicic acid used in WA comes from CSBP Kwinana, with a smaller amount imported from New Zealand.
- Sodium fluoride is produced by neutralising hydrofluoric acid with soda ash or reacting sodium fluorosilicate (a compound of fluorine, hydrogen and silicon) with caustic soda or soda ash. The sodium fluoride used in WA comes from Ixom.
How pure are the products used to fluoridate drinking water?
- All chemicals added to drinking water, including fluorosilicic acid and sodium fluoride must meet the quality standards specified in the Australian Drinking Water Guidelines (external site), published by the National Health and Medical Research Council, as well as be approved by the Department of Health for addition to drinking water.
- The licensed water provider is also required to apply its own strict quality control processes and monitoring programs to ensure that any product added to drinking water meets the highest levels of purity.
How much fluoride is added to drinking water?
- The optimum level of fluoride in fluoridated drinking water supplies across WA is set to achieve the best dental health outcome for the community within the water supply district.
- The optimum level is recommended by the statutory Fluoridation of Public Water Supplies Advisory Committee, based on guidelines published by the National Health and Medical Research Council, Australia’s peak public health policy organisation.
- The optimum level ranges from 0.6 to 0.9 milligram per litre, with a maximum of 1.0 milligram per litre established in the Fluoridation of Public Water Supplies Act 1966 (external site). The optimum level for the Perth metropolitan area is 0.8 milligram per litre, with a range of 0.7 to 1.0 milligram per litre.
- One milligram per litre is equivalent to one part per million.
- The level of fluoride added to public drinking water supplies in WA is similar to other areas in Australia with a similar climate.
- Drinking water delivered to consumers contains the fluoride ion, but it does not contain any sodium fluoride, sodium fluorosilicate or fluorosilicic acid itself.
Environmental Health Directorate
Department of Health WA
PO Box 8172
PERTH BUSINESS CENTRE WA 6849
Telephone: 9388 4999
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