Bicarbonate, chloride, sulphate: read the water type on a label

In short: the type of a mineral water is named after the main anions and cations, the ones that account for more than 20% in equivalent terms. The ion listed first is the one there is less of, and the last one named is the most abundant. Under GOST R 54316-2020, Essentuki No. 4 is a chloride-bicarbonate sodium boric water. The same standard makes Narzan a sulphate-bicarbonate polycationic water with natural carbonation.

How do you read a name like "bicarbonate-chloride sodium"?

The anions come first, bicarbonates, sulphates and chlorides, then the cations, calcium, magnesium and sodium. Only ions that account for more than 20% in equivalent terms make it into the name, that is, more than a fifth of the total. The order runs from the smaller share to the larger, so "chloride-bicarbonate" means there is more bicarbonate than chloride. A second version of the order is often given in brackets: it is the same water, the batches simply vary a little. Special components and the type of carbonation are added at the end.

• The anions come first: bicarbonates, sulphates, chlorides. Then the cations: calcium, magnesium, sodium
• Only ions above 20% in equivalent terms make it into the name, that is, more than a fifth of the total anions or cations once charge is taken into account
• The order runs from the smaller share to the larger. "Chloride-bicarbonate" means there is more bicarbonate than chloride
• A second version of the order is often given in brackets, for example "(bicarbonate-chloride)". It is one and the same water, the batches simply vary a little
• Special components are added at the end, such as "boric", "siliceous" or "ferruginous", along with the type of carbonation

The anions and what each one brings

You can taste every anion. A bicarbonate water is soft, with a faint alkaline note: the EU threshold is more than 600 mg/L of HCO₃. A chloride water is salty, with a threshold of 200 mg/L of Cl. A sulphate water carries a bitter edge, also from 200 mg/L of SO₄. Pure types are rare: most names carry two or three anions at once, as with Essentuki No. 4 and Narzan.

• Bicarbonate water: a soft taste with a faintly alkaline note. The EU threshold is more than 600 mg/L of HCO₃
• Chloride water: a salty taste. The EU threshold is more than 200 mg/L of Cl
• Sulphate water: a light bitter edge. The EU threshold is more than 200 mg/L of SO₄
• Pure types are rare. Most names carry two or three anions, as with Essentuki No. 4 and Narzan

The cations: calcic, magnesic, sodic

Cations shape both the taste and what the water brings to the body. Under EU rules a water is calcic from 150 mg/L of calcium, magnesic from 50 mg/L of magnesium and sodic from 200 mg/L of sodium. A sodic water is recognisable at once by its salty note, a magnesic one by its bitterness. When no single cation dominates and calcium, magnesium and sodium all take a noticeable share, the water is called polycationic, which is exactly how GOST R 54316-2020 describes Narzan.

• Calcic: the EU threshold is more than 150 mg/L of Ca
• Magnesic: the EU threshold is more than 50 mg/L of Mg. Magnesium adds bitterness too
• Sodic: the EU threshold is more than 200 mg/L of Na. You recognise this water at once by its salty note
• "Polycationic" means no single cation dominates: calcium, magnesium and sodium all take a noticeable share

Essentuki No. 4

Under GOST R 54316-2020 this is group VIIIa: a chloride-bicarbonate sodium boric medicinal-table water. In equivalent terms it is 55-80% bicarbonate, 20-45% chloride and more than 80% sodium with potassium. In mg/L on the label: HCO₃ 3400-4850, Cl 1300-2000, Na + K 2000-3000, orthoboric acid 30-70. A mineralisation of 7-10 g/L makes it a medium-mineralised water. It tastes salty with a soft alkaline note, which is why it is drunk in small portions with food.

• Under GOST R 54316-2020: group VIIIa, chloride-bicarbonate (bicarbonate-chloride) sodium, boric, medicinal-table
• In equivalent terms: 55-80% bicarbonate, 20-45% chloride, more than 80% sodium with potassium
• In mg/L on the label: HCO₃ 3400-4850, Cl 1300-2000, Na + K 2000-3000, orthoboric acid 30-70
• Mineralisation 7-10 g/L, medium-mineralised. The taste is salty with a soft alkaline note

Narzan

The same standard puts Narzan in group V: a sulphate-bicarbonate polycationic medicinal-table water with natural carbonation, of the Kislovodsk type. In equivalent terms it is 40-75% bicarbonate, 20-60% sulphate, 20-70% calcium and 10-50% magnesium. In mg/L on the label: HCO₃ 1000-1950, SO₄ 250-1100, Ca 200-600, Mg 50-180, Na + K 50-450. Mineralisation is 2-3.5 g/L. The taste is gentler than Essentuki, with bubbles and a light bitterness from the sulphate and magnesium.

• Under GOST R 54316-2020: group V, sulphate-bicarbonate (bicarbonate-sulphate) polycationic, medicinal-table, naturally carbonated
• In equivalent terms: 40-75% bicarbonate, 20-60% sulphate, 20-70% calcium, 10-50% magnesium, 10-60% sodium with potassium
• In mg/L on the label: HCO₃ 1000-1950, SO₄ 250-1100, Ca 200-600, Mg 50-180, Na + K 50-450
• Mineralisation 2-3.5 g/L, low-mineralised. The taste is gentler than Essentuki, with natural carbonation and a light bitterness from the sulphate and magnesium

Sources

• GOST R 54316-2020: groups of mineral waters, table A.1 (full text)
• Directive 2009/54/EC, Annex III: ion thresholds for label claims