Potassium benzoate is a chemical compound, the potassium salt of benzoic acid. It is produced by a reaction between methyl benzoate and potassium triacetate.

It appears as a white crystalline powder.

What it is used for and where

Cosmetics

Preservative. Any product containing organic, inorganic compounds, water, needs to be preserved from microbial contamination. Preservatives act against the development of harmful microorganisms and against oxidation of the product.

Food

An ingredient included in the European food additives list as E212 and used as a substitute for sodium benzoate as a preservative when there is a need to decrease the sodium content, for example in dietetic foods. 

Safety

In an in vitro study, potassium benzoate was found to be mutagenic, clastogenic and cytotoxic to human lymphocytes however potassium benzoate did not cause a significant increase in DNA damage (1).

The EFSA Panel on Food Additives considered the use of benzoic acid and its sodium and potassium salts as food additives to be of no concern with regard to genotoxicity and ruled out carcinogenic potential (2).

Potassium benzoate studies

Molecular Formula     C₇H₅KO₂    C₆H₅COOK

Molecular Weight      160.21

CAS  582-25-2

UNII    763YQN2K7K

EC Number     209-481-3

DSSTox ID  DTXSID1027219

IUPAC  potassium;benzoate

InChl=1S/C7H6O2.K/c8-7(9)6-4-2-1-3-5-6;/h1-5H,(H,8,9);/q;+1/p-1

InChl Key      XAEFZNCEHLXOMS-UHFFFAOYSA-M

SMILES  C1=CC=C(C=C1)C(=O)[O-].[K+]

MDL number  MFCD00013061

PubChem Substance ID    57648337

Beilstein   3719165

NACRES   NA.21

NCI    C84094

Nikkaji      J43.329B

RXCUI       54991

Synonyms: 

• Benzoic acid, potassium salt

References_____________________________________________________________________

(1) Zengin N, Yüzbaşıoğlu D, Unal F, Yılmaz S, Aksoy H. The evaluation of the genotoxicity of two food preservatives: sodium benzoate and potassium benzoate. Food Chem Toxicol. 2011 Apr;49(4):763-9. doi: 10.1016/j.fct.2010.11.040.

(2) EFSA Panel on Food Additives and Nutrient Sources (ANS). (2016). Scientific Opinion on the re‐evaluation of benzoic acid (E 210), sodium benzoate (E 211), potassium benzoate (E 212) and calcium benzoate (E 213) as food additives. EFSA Journal, 14(3), 4433.

Abstract. The EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) was asked to deliver a scientific opinion re-evaluating benzoic acid (E 210), sodium benzoate (E 211), potassium benzoate (E 212) and calcium benzoate (E 213) when used as food additives. Benzoic acid and its sodium and potassium salts are rapidly absorbed after oral administration. The Panel considered that the absorption, distribution, metabolism and excretion of calcium benzoate will be similar to sodium or potassium salt and, therefore, read-across between the salts was possible. The results of short-term and subchronic studies on benzoic acid and its salts indicate that their toxicity is low. The Panel considered that the use of benzoic acid and its sodium and potassium salts as food additives does not raise a concern with respect to genotoxicity and, based on read-across, also considered that this conclusion is applicable for calcium benzoate. Moreover, the Panel noted that the available data did not indicate any carcinogenic potential. A four-generation reproductive toxicity study with benzoic acid in the diet in rats was considered by the Panel as the pivotal study and a no observed adverse effect level of 500 mg benzoic acid/kg body weight (bw) per day, the highest dose tested, was identified. From the aforementioned studies, the Panel derived an acceptable daily intake (ADI) of 5 mg/kg bw per day (expressed as benzoic acid) using an uncertainty factor of 100. Taking into account food categories for which direct addition of benzoic acid-benzoates is authorised, the group ADI was exceeded in the brand-loyal scenario in particular for toddlers and children consuming on a regular basis flavoured drinks. Considering additional exposure due to carry-over, the intake could be increased by up to two to three fold for all high-level consumers compared to the previous scenario with only direct addition to food. This results in exceedance of the group ADI in toddlers and children for the non-brand-loyal scenario. The main food categories contributing to this exceedance were unprocessed fruits and vegetables and flavoured drinks.