Potassium benzoate

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ImageFile=Potassium benzoate.pngImageSize=200px
IUPACName=Potassium benzoate
OtherNames=Benzoic acid, potassium salt
Section1= Chembox Identifiers
CASNo=582-25-2
PubChem=11399
EINECS = 209-481-3
SMILES=C1=CC=C(C=C1)C(=O) [O-] . [K+]
Section2= Chembox Properties
Formula=C₇H₅KO₂
MolarMass=160.2117
Appearance=White solid
Density=
MeltingPt=
BoilingPt=
Solubility=
Section3= Chembox Hazards
MainHazards=
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Autoignition=

Potassium benzoate, the potassium salt of benzoic acid, is a food preservative that inhibits the growth of mold, yeast and some bacteria. It works best in low-pH products, below 4.5, where it exists as benzoic acid.

Acidic foods and beverages such as fruit juice (citric acid), sparkling drinks (carbonic acid), soft drinks (phosphoric acid), and pickles (vinegar) are preserved with potassium benzoate.

Also used as the whistle in many fireworks, since it is stable.

It is approved for use in most countries including Canada, the U.S., and the EU, where it is designated by the E number E212. In the EU, it is not recommended for consumption by children. [cite journal | author= Cosmetic Ingredient Review Expert Panel Bindu Nair | title= Final Report on the Safety Assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate| journal=Int J Tox | year=2001 | issue= 20 (Suppl. 3) |pages=23–50 ]

Mechanism of food preservation

The mechanism of food preservation begins 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%. [cite journal | author=Krebs HA, Wiggins D, Stubbs M | title= Studies on the mechanism of the antifungal action of benzoate | journal= Biochem J | year=1983 | issue=214 |pages=657–663 ]

Safety and health

In combination with ascorbic acid (vitamin C), sodium and potassium benzoate may form benzene, a known carcinogen. Heat, light and shelf life can affect the rate at which benzene is formed. The Food and Drug Administration was performing tests in 2006, but the Environmental Working Group is calling for the FDA to publicly release all tests and use their authority to force companies to reformulate to avoid the potential benzene forming combination. [ [http://www.ewg.org/issues/toxics/20060404/index.php Press Release] from the Environmental Working Group]

Potassium Benzoate (or E212) was recently described by the Food Commission, who campaign for 'safer, healthier food in the UK', as "mildly irritant to the skin, eyes and mucous membranes". [ [http://www.foodcomm.org.uk/press_07_additives.htm Published in The Food Magazine issue 77] from the Food Commission UK]

Cats have a significantly lower tolerance to benzoic acid and its salts than rats and mice. [cite journal| author= Bedford PG, Clarke EG |title=Experimental benzoic acid poisoning in the cat|journal=Vet Rec |year=1972|pages=53–58|issue=90 PMID 4672555]

References