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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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Physical & Chemical properties

Water solubility

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Description of key information

Tartaric acid and its salts are soluble in water, with some differences among individual substances. calcium tartrate and potasim hydrogen tartrare te less soluble than tartaric acid and the other salts.

The determination of this property was done according to a weight of evidence approach based on available literature reference and QSAR calculation. 1390 mg/L (20 °C)

Key value for chemical safety assessment

Additional information

A collection of the water solubility data was performed for tartaric acid and its salts (i.e. monosodium, monopotassium, sodium potassium, sodium, potassium and calcium tartrate). A summary of these data (with the indication of the minimum-maximum value of water solubility) is detailed below.

EC name

water solubility (g/L)

interpretation of result

(+)-tartaric acid


very soluble

(-)-tartaric acid 


very soluble

(±)-tartaric acid


very soluble

mesotartaric acid


very soluble

potassium hydrogen tartrate



potassium sodium tartrate


very soluble

calcium tartrate


moderately soluble

sodium hydrogen tartrate


very soluble

disodium tartrate


very soluble

dipotassium tartrate



The water solubility of dextrotartaric ((+)-tartaric acid), levotartaric ((-)-tartaric acid) and mesotartaric acid are of the same order of magnitude. Only the solubility of the racemic form of acid tartaric ((±)-tartaric acid) is lower than the other forms of tartaric acid. Overall, all forms of tartaric acid are judged as very soluble in water.

With regard to acid tartaric salts, although there are significant differences in the found values, all substances resulted to be water soluble.