What goes in
Australian water utilities use one of three compounds:
- Fluorosilicic acid (also called hydrofluorosilicic acid), a liquid used in most large plants.
- Sodium fluorosilicate, a powder.
- Sodium fluoride, a powder used mostly in smaller plants.
Most fluorosilicic acid is recovered as a co-product of phosphate fertiliser manufacturing. It must meet drinking water chemical standards before use.
How much
Fluoride is dosed to between 0.6 and 1.1 mg/L, depending on climate (warmer places, where people drink more water, get less). The health-based maximum in the Australian Drinking Water Guidelines is 1.5 mg/L. Some towns, such as Birdsville and Julia Creek in Queensland, have natural levels above that.
How to check your own supply
- Find your water provider (usually your council or a state water corporation).
- Search for its annual drinking water quality report. Fluoride is listed in mg/L, often by supply zone.
- If the report says "not dosed" or shows levels under 0.3 mg/L, fluoride is not being added.
- You can request monthly readings directly from the utility.
Which filters remove fluoride
- Reverse osmosis: removes most fluoride.
- Distillation: removes most fluoride.
- Activated alumina and bone char filters: designed to target fluoride.
- Standard carbon jug and fridge filters: remove little or no fluoride. Check the manufacturer's test results.
Look up your town on the map to see whether fluoride is added.