Potassium trihydrogen dioxalate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study is performed in line with OECD guideline 471 (Ames test), materials and methods are well described. A deviation from this guideline is that the test is not performed with Salmonella typhimurium strain TA 102 or E. coli strain WP uvrA or WP uvrA (pKM101) in order to detect cross-linking mutagens. Furthermore, no detailed information is available on the results.

Data source

Reference

Reference Type:

publication

Title:

Primary mutagenicity screening of food additives currently used in Japan

Author:

Ishidate Jr., M., Sofuni, T., Yoshikawa, K., Hayashi, M., Nohmi, T., Sawada, M., Matsuoka, A.

Year:

1984

Bibliographic source:

Food Chemistry and Toxicology, Vol. 22, No. 8, p 623-636

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

6 different strains of Salmonella typhimurium were used, but one of the recommended strain TA102 (or an E.coli strain) was not included.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Oxalic acid

EC Number:

205-634-3

EC Name:

Oxalic acid

Cas Number:

144-62-7

Molecular formula:

C2H2O4

IUPAC Name:

oxalic acid

Details on test material:

- Name of test material (as cited in study report): Oxalic acid
- Analytical purity: 99.7%
- Source: Japan Food Additives Association (Tokyo)

Method

Target gene:

TA1535, TA1537, TA100, TA98, TA94, TA92

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

S. typhimurium, other: TA92 and TA94

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix (prepared from the liver of Fischer rats)

Test concentrations with justification for top dose:

Six concentrations tested, with a maximum dose of 10.0 mg/plate. No further details reported.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: phosphate buffer
- Justification for choice of solvent/vehicle: test substance soluble in water

Controls

Negative solvent / vehicle controls:

yes

Remarks:

phosphate buffer

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

DURATION
- Preincubation period: Cells were pre-incubated with both the test sample and the S-9 mix for 20 min at 37°C
- Exposure duration: 2 days

SELECTION AGENT (mutation assays): histamine

NUMBER OF REPLICATIONS: duplicates

Evaluation criteria:

The result was considered positive if the number of colonies found was twice the number in the control.

Statistics:

No data

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 2

Species / strain:

S. typhimurium, other: TA92 and TA94

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

not specified

Additional information on results:

No data

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

The following table is reproduced from the table in the publication (only the part concerning oxalic acid is reproduced):

Additive	CAS no.	Purity (%)	Max dose (mg/plate)	Solvent	Result
Oxalic acid	144-62-7	99.7	10.0	Phosphate buffer	-

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Oxalic acid does not have mutagenic properties in the Ames test, under the current test conditions.

Executive summary:

200 food additives used in Japan, among which oxalic acid, were tested for mutagenic properties in the Ames test. Six strains of Salmonella typhimurium were tested: TA1535, TA1537, TA98, TA100, TA92 and TA94, with and without metabolic activation (S-9 from rat liver). Oxalic acid tested negative in all strains, with and without activation. It can be concluded that oxalic acid does not have mutagenic properties in the Ames test, under the current test conditions.