For Italian law, commercially available mineral waters can be divided into several categories according to a legislative decree Decree-law 8th October 2011 n. 176.
The "Mineral waters", distinct from "potable water intended for human consumption", are classified according to extremely stringent parameters.
Fixed residue: total content of salts in mg obtained from 1 liter of mineral water after 180 ° heating and evaporation. Based on the values of fixed residue, the Italian legislation, since 1980, distinguishes mineral waters in:
- minimal mineralized waters (fixed residue < 50 mg/l);
- oligomineral waters (fixed residue between 50 and 500 mg/l);
- medium minerals (fixed residues between 500 and 1500 mg/l);
- waters rich in mineral salts (fixed residues above 1500 mg/l.
The Italian legislation currently in force provides for a classification based on the predominant and qualifying chemical elements on which it is possible to predict, at least theoretically, the biological, dietary and medicinal effects of mineral water. So we have:
- bicarbonate waters, if the content of bicarbonate is more than 600 mg / l;
- sulfuric acid, if the sulfate content is greater than 200 mg / l;
- chlorinated water, if the chlorine content is greater than 200 mg / l;
- calcite waters, if the calcium content is greater than 150 mg / l;
- magnesium water, if the magnesium content is greater than 50 mg / l;
- fluorinated waters, if the fluoride content is greater than 1 mg / l;
- ferruginous waters, if the bivalent iron content is greater than 1 mg / l;
- sodium, if the sodium content is greater than 200 mg / l;
- hyposodic waters, if the sodium content is less than 20 mg / l.
