Swedish Chemicals Agency logotype
column.gif (842 bytes)

Information on substances


back


In Swedish

 

Sodium benzoate (2006)

 

CAS no
532-32-1

Synonyms
E211

Physical data
Melting point:  >300 ░C
Boiling point: >300 ░C
Freezing point: -101 ░C
Vapour pressure
Very low
Water solubility: 560 g /l
Molecular weight: 144.1 g/mol

The substance is a white crystalline powder that gives a colourless water solution. Flakes and granulates are other possible forms. Water solutions are slightly basic (pH about 8). The substance does no smell and has a harsh sour taste.

Sodium benzoate occurs naturally in many berries and fruits, such as lingonberry and apple, in a concentration of about 0.05 %.

Sodium benzoate is produced by a reaction between benzoic acid and sodium hydroxide or sodium carbonate. Solid sodium benzoate is precipitated by cooling and evaporation of the reaction liquid. The production in and import of sodium benzoate to EU is about 10 000 to 50 000 tonnes/year (2000).

The antimicrobial effect mainly affects yeast and bacteria and is most effective at acid conditions (pH < 4). It is less effective on mould fungus. Sodium benzoate does not kill micro-organisms. It just stops the organism to grow.

An important use area for sodium benzoate is as a food preservative. It is used in e.g. cold beverages (especially aerated), margarine, fish products, roe products, marmalade, jam, pickle, salad dressing and animal food. Sodium benzoate is also used as a preservative in various technical water-based preparations such as cosmetics, paints, adhesives, cleaning agents and metal treatment liquids. Other uses are as anti-corrosion agent in antifreeze liquids (e.g. for cars), as additive in plastic to improve strength and transparency and as stabilizer in photo developers. Sodium benzoate is also used as raw material for chemical synthesis, e.g. of benzyl benzoate.

Normally used concentrations are 0.05 to 0.1 % in fruit juice and 0.1 % in skin creams. The regulatory limit in food and animal food in the US is 0.1 %.

Sodium benzoate can in the presence of ascorbic acid form benzene.

One advantage of sodium benzoate compared with other preservatives is its low production costs.

sidtopp


Contact person: Margareta Ístman,  Tel +468 519 411 62
Swedish Chemicals Agency Box 2 SE-172 13 Sundbyberg, kemi@kemi.se
Tel +468 519 411 00 Fax +468 735 7698