Potassium benzoate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro DNA damage and/or repair study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Peer reviewed journal
Sodium and potassium benzoate both assessed, helping establish that the cation has little impact on the outcome of these tests
Although good method details included, the study was only performed in the absence of S-9 metabolic activation.

Data source

Reference

Reference Type:

publication

Title:

The evaluation of the genotoxicity of two food preservatives: Sodium benzoate and potassium benzoate

Author:

N. Zengin a, D. Yüzbas, et al

Year:

2010

Bibliographic source:

Food and Chemical Toxicology 49 (2011) 763–769

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 479 (Genetic Toxicology: In Vitro Sister Chromatid Exchange Assay in Mammalian Cells)

Principles of method if other than guideline:

The slides were stained with Giemsa. The number of SCEs (25 cells from each donor, with two doners, making a total of 50 cells per concentration) under the second metaphases was scored. In addition, 100 cells from each donor were scored for determination of the replication index (RI).

GLP compliance:

not specified

Remarks:

data taken from publication - GLP details not given

Type of assay:

sister chromatid exchange assay in mammalian cells

Test material

Test material information

Constituent 1

Reference substance name:

Potassium benzoate

EC Number:

209-481-3

EC Name:

Potassium benzoate

Cas Number:

582-25-2

Molecular formula:

C7H6O2.K

IUPAC Name:

potassium benzoate

Specific details on test material used for the study:

Obtained from Merck
(Note Potassium Benzoate also assessed)

Method

Species / strain

Species / strain / cell type:

other: Human

Remarks:

Two doners

Details on mammalian cell type (if applicable):

The study was carried out using blood samples from two healthy donors (nonsmokers, of age 25 years), with no medication for at least 3 weeks prior, and not having had a radiological examination within the prior 3 months.

Metabolic activation:

without

Test concentrations with justification for top dose:

6.25, 12.5, 25, 50, and 100 ug/ml for sodium benzoate, with reduction in mitotic index at over 12.5 ug/ml
62.5, 125, 250, 500, and 1000 ug/ml for potassium benzoate, with reduction in mitotic index at over 250 ug/ml

Vehicle / solvent:

Water

Controls

Untreated negative controls:

yes

Positive controls:

yes

Positive control substance:

mitomycin C

Details on test system and experimental conditions:

Whole blood from two doners was added to chromosome medium B (containing fetal bovine serum)

Statistics:

The t-test was applied

Results and discussion

Test results

Key result

Species / strain:

lymphocytes: Human

Metabolic activation:

without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

The same level of positive response was seen for potassium and sodium benzoate

Applicant's summary and conclusion

Conclusions:

These benzoate salts led to positive effects in-vitro without S-9
The same level of positive response was seen for potassium and sodium benzoate suggesting that the metal ion is not significant in considering possible mutagenic effects, although the metal ion did influence cyto-toxicity (sodium being more toxic than potassium).
These results are in line with other publications and reviews of in-vitro assessment of benzoate salts.