Potassium benzoate

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Structural formula
Structure of potassium benzoate
General
Surname Potassium benzoate
other names

E 212

Molecular formula C 7 H 5 KO 2
Brief description

white to off-white solid

External identifiers / databases
CAS number 582-25-2
EC number 209-481-3
ECHA InfoCard 100.008.621
PubChem 23661960
ChemSpider 10921
Wikidata Q413611
properties
Molar mass 160.21 g mol −1
Physical state

firmly

Melting point

> 300 ° C

solubility

approx. 492 g / l (20 ° C)

safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 319
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Potassium is the potassium - salt of benzoic acid . It is approved as a food additive E 212 .

effect

Potassium benzoate has a bacteriostatic and fungistatic effect and is therefore used as a food additive (E 212) to preserve food (optimum effect at pH <3.6). This means that the treated food remains preserved over a longer period of time. Potassium benzoate is only suitable for preserving sour or sour products. It protects against mold , yeast , unwanted secondary fermentation and, in combination with sulfur dioxide, also against bacterial spoilage. It is less effective against lactic acid bacteria and against several pathogens.

use

Potassium benzoate can be synthesized in a Henkel reaction by thermal- catalytic disproportionation with the addition of carbon dioxide , potassium terephthalate :

Henkel reaction overview2

As a by-product produced benzene .

Alternatively, potassium benzoate can be used as a preservative in the following foods: mayonnaise, marinades, ready-made salads, cake fillings, margarine, fruit juices, liquid tea concentrates, jellies, jams, vegetables pickled in vinegar, oil or brine, fish products, unheated dairy products, chewing gum, mustard, Condiments, diet foods and flavored mineral waters.

It is also used as a lubricant in the manufacture of tablets and as a corrosion inhibitor for water-bearing systems.

compatibility

Potassium benzoate can cause allergies and hives . People with asthma , hay fever or skin allergies are particularly susceptible to this additive. Especially allergy sufferers who are sensitive to acetylsalicylic acid should avoid potassium benzoate. Combinations with the preservatives sulfur dioxide (E 220), sodium sulfite (E 221), sodium hydrogen sulfite (E 222), sodium disulfite (E 223), potassium disulfite (E 224), potassium sulfite ( E 225 ), calcium sulfite ( E 226 ), calcium hydrogen sulfite ( E 227 ) and with azo dyes increase the negative effects.

Individual evidence

  1. ↑ a b Data sheet potassium benzoate from AlfaAesar, accessed on December 15, 2010 ( PDF )(JavaScript required) .
  2. ↑ a b c Entry on potassium benzoate in the GESTIS substance database of the IFA , accessed on December 16, 2019 (JavaScript required)
  3. ↑ a b Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set , John Wiley & Sons, Hoboken, New Jersey, 2009 , ISBN 978-0-471-70450-8 , p. 1380.

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