| Sodium benzoate | |
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| Identifiers | |
| CAS number | 532-32-1  |
| PubChem | 517055 |
| ChemSpider | 10305 |
| UNII | OJ245FE5EU |
| ChEMBL | CHEMBL1356 |
| RTECS number | DH6650000 |
| Jmol-3D images | Image 1 |
| Properties | |
| Molecular formula | NaC6H5CO2 |
| Molar mass | 144.11 g/mol |
| Appearance | white or colorless crystalline powder |
| Odor | odorless |
| Density | 1.497 g/cm3 |
| Melting point | 300 °C, 573 K, 572 °F |
| Solubility in water | soluble |
| Solubility | soluble in ethanol |
| Acidity (pKa) | 4.202[1] |
| Hazards | |
| NFPA 704 | 
1
2
0
|
| Flash point | 100 °C |
| Autoignition temperature |
500 °C |
| LD50 | 4100 mg/kg (oral, rat) |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Uses
Sodium benzoate is a preservative. 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.[2][3] As a food additive, sodium benzoate has the E number E211.
It is also used in fireworks as a fuel in whistle mix, a powder that emits a whistling noise when compressed into a tube and ignited. The fuel is also one of the fastest burning rocket fuels and provides a lot of thrust and smoke. It does have its downsides: there is a high danger of explosion when the fuel is sharply compressed because of the fuel's sensitivity to impact.
Sodium benzoate is produced by the neutralization of benzoic acid with sodium hydroxide.[4] Benzoic acid is detectable at low levels in cranberries, prunes, greengage plums, cinnamon, ripe cloves, and apples. Though benzoic acid is a more effective preservative, sodium benzoate is more commonly used as a food additive because benzoic acid does not dissolve well in water.[4] Concentration as a preservative is limited by the FDA in the U.S. to 0.1% by weight. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647–825 mg/kg of body weight per day.[5][6]
Cats have a significantly lower tolerance against benzoic acid and its salts than rats and mice.[7] Sodium benzoate is, however, allowed as an animal food additive at up to 0.1%, according to AFCO's[specify] official publication.[8]
Mechanism of food preservation
The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH changes to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase is decreased by 95%,[9] thereby inhibiting the growth and survival of micro-organisms that cause food spoilage.Production
Sodium benzoate is created 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.Safety and health
Main article: Benzene in soft drinks
In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate form benzene, a known carcinogen. However, in most beverages that contain both, the benzene levels are below those considered dangerous for consumption.[10] Heat, light and shelf life can affect the rate at which benzene is formed.Hyperactivity
Research published in 2007 for the UK's Food Standards Agency (FSA) suggests that certain artificial colours, when paired with sodium benzoate (E211) may be linked to hyperactive behaviour. The results were inconsistent regarding sodium benzoate, so the FSA recommended further study.[11][12][13]Professor Jim Stevenson from Southampton University, and author of the report, said: "This has been a major study investigating an important area of research. 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. However, parents should not think that simply taking these additives out of food will prevent hyperactive disorders. We know that many other influences are at work but this at least is one a child can avoid."[13]
Two mixtures of additives were tested in the research:[13]
Mix A:
Mix B:
- Sunset yellow (E110)
- Quinoline yellow (E104)
- Carmoisine (E122)
- Allura red (E129)
- Sodium benzoate (E211)
On 10 April 2008, the Foods Standard Agency called for a voluntary removal of the colours (but not sodium benzoate) by 2009.[14] In addition, it recommended there should be action to phase them out in food and drink in the European Union (EU) over a specified period.[15]
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 E211 from its other products — including Sprite, Fanta, and Oasis — as soon as a satisfactory alternative is discovered.[16]
Compendial status
- British Pharmacopoeia[17][18][19]
- European Pharmacopoeia[17]
- Food Chemicals Codex[17]
- Japanese Pharmacopoeia [20]
- United States Pharmacopeia 29[21]
References
- ^ Harris, Daniel (2010). Quantitative Chemical Analysis (8 ed.). New York: W. H. Freeman and Company. pp. AP12. ISBN 9781429254366.
- ^ http://www.cosmeticsdatabase.com/product.php?prod_id=49779
- ^ Sodium benzoate in Robitussin cough
- ^ a b INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
- ^ Concise International Chemical Assessment Document 26: Benzoic acid and sodium benzoate
- ^ 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.
- ^ AFCO (2004). Official Publication. p. 262.
- ^ 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.
- ^ FDA, 2006. "Data on Benzene in Soft Drinks and Other Beverages, " United States Food and Drug Administration.
- ^ Food Standards Agency issues revised advice on certain artificial colours 6 September 2007
- ^ Food Colorings and Hyperactivity "Myomancy" 7 September 2007
- ^ a b c Agency revises advice on certain artificial colours Food Standards Agency 11 September 2007
- ^ BBC Europe-wide food colour ban call 10 April 2008
- ^ FSA Board discusses colours advice 10 April 2008
- ^ The Daily Mail DNA Damage Fear 24 May 2008
- ^ a b c Sigma Aldrich. "Sodium benzoate". Retrieved 17 July 2009.
- ^ Therapeutic Goods Administration. "Chemical Substances" (PDF). Retrieved 17 July 2009.
- ^ British Pharmacopoeia Commission Secretariat. "Index (BP)". 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.
External links
- 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