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E 466 Sodium carboxy methyl cellulose, cellulose gum - EU specification

COMMISSION REGULATION (EU) No 231/2012 of 9 March 2012


CMC; NaCMC; Sodium CMC;


Carboxy methyl cellulose is the partial sodium salt of a carboxymethyl ether of cellulose, the cellulose being obtained directly from strains of fibrous plant material


Chemical name: Sodium salt of the carboxymethyl ether of cellulose

Chemical formula: The polymers contain substituted anhydroglucose units with the following general formula:

C 6 H 7 O 2 (OR 1 )(OR 2 )(OR 3 ), where R 1 , R 2 , R 3 each may be one of the following:

— H

— CH 2 COONa


Molecular weight: Higher than approximately 17 000 (degree of polymerisation approximately 100)

Assay: Content on the anhydrous basis not less than 99,5 %


Slightly hygroscopic white or slightly yellowish or greyish odourless and tasteless, granular or fibrous powder


Solubility: Yields a viscous colloidal solution with water. Insoluble in ethanol

Foam test: A 0,1 % solution of the sample is shaken vigorously. No layer of foam appears. (This test permits the distinction of sodium carboxymethyl cellulose from other cellulose ethers)

Precipitate formation: To 5 ml of a 0,5 % solution of the sample, add 5 ml of 5 % solution of copper sulphate or of aluminium sulphate. A precipitate appears. (This test permits the distinction of sodium carboxymethyl cellulose from other cellulose ethers and  from gelatine, locust bean gum and tragacanth)

Colour reaction: Add 0,5 g powdered carboxy methyl cellulose sodium to 50 ml of water, while stirring to produce an uniform dispersion. Continue the stirring until a clear solution is produced, and use the solution for the following test:

To 1 mg of the sample, diluted with an equal volume of water, in a small test tube, add 5 drops of 1-naphthol solution. Incline the test tube, and carefully introduce down the side of the tube 2 ml of sulphuric acid so that it forms a lower layer. A red-purple colour

develops at the interface

pH: Not less than 5,0 and not more than 8,5 (1 % colloidal solution)


Degree of substitution: Not less than 0,2 and not more than 1,5 carboxymethyl groups (-CH 2 COOH) per anhydroglucose unit

Loss on drying: Not more than 12 % (105 °C to constant weight)

Arsenic: Not more than 3 mg/kg

Lead: Not more than 2 mg/kg

Mercury: Not more than 1 mg/kg

Cadmium: Not more than 1 mg/kg

Total glycolate: Not more than 0,4 %, calculated as sodium glycolate on the anhydrous basis

Sodium: Not more than 12,4 % on the anhydrous basis