To make toothpaste, you have to mine …

Next time you are brushing your teeth, consider what goes into the toothpaste...

Water - 20–42%

Water – 20 to 42 per cent

Abrasives – 50 per cent, for example, aluminium hydroxide, calcium carbonate, calcium hydrogen phosphates, silica, zeolites, and hydroxyapatite

Fluorides – 0.1 per cent, typically sodium fluoride, or olaflur (an organic salt of fluoride), or sodium monofluorophosphate

Other components include anti-bacterial agents, anti-drying agents, surfactants or foaming agents, colours and flavours, and remineralisers, such as hydroxyapatite and calcium phosphate

The mineral abrasive particles in toothpaste are made, in order, from crushed aluminium ores, limestone, white sands, while zeolites are a class of minerals related to clays. These minerals are typically quarried from surface industrial mineral deposits. Except for aluminium ores, these minerals occur in New Zealand. Hydroxyapatite occurs naturally in animal bones.

Sodium fluoride is a by-product of making fertiliser from rock phosphate, a naturally-occurring mineral, currently imported into New Zealand. Fluoride is added to reduce the risk of cavities.

The phosphate-bearing minerals occurring in bones have the property of strengthening and repairing tooth enamel, hence the term “remineralisers” – a reminder that our teeth are made of minerals.