E211, benzoate of soda
|Molar mass||144.10 g·mol−1|
|Appearance||white or colorless crystalline powder|
|Melting point||410 °C (770 °F; 683 K)|
|62.69 g/100 mL (0 °C)
62.78 g/100 mL (15 °C)
62.87 g/100 mL (30 °C)
71.11 g/100 mL (100 °C)
|Solubility||soluble in liquid ammonia, pyridine|
|Solubility in methanol||8.22 g/100 g (15 °C)
7.55 g/100 g (66.2 °C)
|Solubility in ethanol||2.3 g/100 g (25 °C)
8.3 g/100 g (78 °C)
|Solubility in 1,4-Dioxane||0.818 mg/kg (25 °C)|
|GHS signal word||Warning|
|Flash point||100 °C (212 °F; 373 K)|
|500 °C (932 °F; 773 K)|
LD50 (Median lethal dose)
|4100 mg/kg (oral, rat)|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Sodium benzoate has the chemical formula NaC7H5O2; it is a widely used food preservative, with E number E211. It is the sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid. Benzoic acid occurs naturally at low levels in cranberries, prunes, greengage plums, cinnamon, ripe cloves, and apples.
Sodium benzoate is a preservative. As a food additive, sodium benzoate has the E number E211. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics. Concentration as a preservative is limited by the FDA in the U.S. to 0.1% by weight. Sodium benzoate is also allowed as an animal food additive at up to 0.1%, according to AFCO's official publication.
Sodium benzoate is used as a treatment for urea cycle disorders due to its ability to bind amino acids. This leads to excretion of these amino acids and a decrease in ammonia levels. Recent research shows that sodium benzoate may be beneficial as an add-on therapy (1 gram/day) in schizophrenia. Total Positive and Negative Syndrome Scale scores dropped by 21% compared to placebo.
Mechanism of food preservation
The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH falls to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase decreases sharply which inhibits the growth and survival of microorganisms that cause food spoilage.
Sodium benzoate is produced by the neutralization of benzoic acid with sodium hydroxide. Sodium benzoate can also be prepared by adding benzoic acid to a hot concentrated solution of sodium carbonate until effervescence ceases. The solution is then evaporated, cooled and allowed to crystallize or evaporate to dryness, and then granulated.
Health and safety
In the United States, sodium benzoate is designated as generally recognized as safe (GRAS) by the Food and Drug Administration. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647–825 mg/kg of body weight per day.
Association with benzene in soft drinks
In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate form benzene, a known carcinogen. When tested by the FDA, most beverages that contained both ascorbic acid and benzoate had benzene levels that were below those considered dangerous for consumption by the World Health Organization (5 ppb). Most of the beverages that tested higher have been reformulated and subsequently tested below the safety limit. Heat, light and shelf life can increase the rate at which benzene is formed.
Research published in 2007 for the UK's Food Standards Agency (FSA) suggests that certain artificial colors, when paired with sodium benzoate, may be linked to hyperactive behavior. The results were inconsistent regarding sodium benzoate, so the FSA recommended further study. The Food Standards Agency concluded that the observed increases in hyperactive behavior, if real, were more likely to be linked to the artificial colors than to sodium benzoate. The report's author, Jim Stevenson from Southampton University, said: "The results suggest that consumption of certain mixtures of artificial food colours and sodium benzoate preservative are associated with increases in hyperactive behaviour in children. . . . Many other influences are at work but this at least is one a child can avoid."
In response to consumer insistence on a more natural product, the Coca Cola Company is in the process of phasing sodium benzoate out of Diet Coke. The company has stated it plans to remove sodium benzoate from its other products — including Sprite, Fanta, and Oasis — as soon as a satisfactory alternative is discovered.
- British Pharmacopoeia
- European Pharmacopoeia
- Food Chemicals Codex
- Japanese Pharmacopoeia 
- United States Pharmacopeia 29
- Sigma-Aldrich Co., Sodium benzoate. Retrieved on 2014-05-23.
- "Skin Deep® Cosmetics Database | Environmental Working Group". Cosmeticsdatabase.com. Retrieved 2013-01-14.
- "Sodium benzoate in Robitussin cough". Rxmed.com. Retrieved 2013-01-14.
- CFR - Code of Federal Regulations Title 21
- AFCO (2004). "Official Publication". p. 262.
- Häberle, J; Boddaert, N; Burlina, A; Chakrapani, A; Dixon, M; Huemer, M; Karall, D; Martinelli, D; Crespo, PS; Santer, R; Servais, A; Valayannopoulos, V; Lindner, M; Rubio, V; Dionisi-Vici, C (2012). "Suggested guidelines for the diagnosis and management of urea cycle disorders". Orphanet journal of rare diseases 7: 32. doi:10.1186/1750-1172-7-32. PMC 3488504. PMID 22642880.
- Wilcken, B (2004). "Problems in the management of urea cycle disorders". Molecular genetics and metabolism. 81 Suppl 1: S86–91. doi:10.1016/j.ymgme.2003.10.016. PMID 15050980.
- Add-on Treatment of Benzoate for Schizophrenia A Randomized, Double-blind, Placebo-Controlled Trial of d-Amino Acid Oxidase Inhibitor December 2013
- Cinnamon May Be Used to Halt the Progression of Parkinson’s disease - Rush University, published in Journal of Neuroimmune Pharmacology Cinnamon Treatment Upregulates Neuroprotective Proteins Parkin and DJ-1 and Protects Dopaminergic Neurons in a Mouse Model of Parkinson’s Disease
- Krebs HA, Wiggins D, Stubbs M, Sols A, Bedoya F (September 1983). "Studies on the mechanism of the antifungal action of benzoate". Biochem. J. 214 (3): 657–63. PMC 1152300. PMID 6226283.
- "International Programme On Chemical Safety". Inchem.org. Retrieved 2013-01-14.
- CFR - Code of Federal Regulations Title 21
- "Concise International Chemical Assessment Document 26: Benzoic acid and sodium benzoate". Inchem.org. Retrieved 2013-01-14.
- Cosmetic Ingredient Review Expert Panel Bindu Nair (2001). "Final Report on the Safety Assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate". Int J Tox 20 (Suppl 3): 23–50. doi:10.1080/10915810152630729. PMID 11766131.
- Bedford PG, Clarke EG (January 1972). "Experimental benzoic acid poisoning in the cat". Vet. Rec. 90 (3): 53–8. doi:10.1136/vr.90.3.53. PMID 4672555.
- "Data on Benzene in Soft Drinks and Other Beverages". United States Food and Drug Administration. 16 May 2007. Retrieved 7 November 2013.
- Food Standards Agency issues revised advice on certain artificial colours 6 September 2007
- Food Colorings and Hyperactivity "Myomancy" 7 September 2007
- Agency revises advice on certain artificial colours, Food Standards Agency, 11 September 2007
- The Daily Mail DNA Damage Fear 24 May 2008
- Sigma Aldrich. "Sodium benzoate". Retrieved 17 July 2009.
- Therapeutic Goods Administration. "Chemical Substances" (PDF). Retrieved 17 July 2009.
- British Pharmacopoeia Commission Secretariat. "Index (BP)" (PDF). Retrieved 2 March 2010.
- "Japanese Pharmacopoeia 15th Edition". Retrieved 2 March 2010.
- The United States Pharmacopeial Convention. "Revisions to USP 29–NF 24". Retrieved 17 July 2009.
|Wikimedia Commons has media related to Benzoates.|
|Wikimedia Commons has media related to Benzoate salts.|
- International Programme on Chemical Safety - Benzoic Acid and Sodium Benzoate report
- Kubota K, Ishizaki T (1991). "Dose-dependent pharmacokinetics of benzoic acid following oral administration of sodium benzoate to humans". Eur. J. Clin. Pharmacol. 41 (4): 363–8. doi:10.1007/BF00314969. PMID 1804654.
Although the maximum rate of biotransformation of benzoic acid to hippuric acid varied between 17.2 and 28.8 mg.kg-1.h-1 among the six individuals, the mean value (23.0 mg.kg-1.h-1) was fairly close to that provided by daily maximum dose (0.5 g.kg-1.day-1) recommended in the treatment of hyperammonaemia in patients with inborn errors of ureagenesis
- Andersen A (2006). "Final report on the safety assessment of benzaldehyde". Int. J. Toxicol. 25 (Suppl 1): 11–27. doi:10.1080/10915810600716612. PMID 16835129.
- Sodium Benzoate A Cause of Hyper Kids (TIME.com)
- Safety data for sodium benzoate
- The Ketchup Conundrum
- ChemSub Online: Sodium benzoate