Disodium oxalate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / 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.

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

Specific details on test material used for the study:

- 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

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

other: S. typhimurium TA92 and TA94

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/solvent 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

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 TA 1537

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 3

Species / strain:

S. typhimurium TA 98

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 4

Species / strain:

S. typhimurium 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 5

Species / strain:

other: S. typhimurium TA92

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 6

Species / strain:

other: S. typhimurium TA94

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

Any other information on results incl. tables

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

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: 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, including oxalic acid, were tested for mutagenic properties in the Ames test. The strains of Salmonella typhimurium used are the following: TA 92, TA1535, TA100, TA1537, TA94, and TA98, with and without metabolic activation (S-9 prepared from rat liver). Negative results are showed with oxalic acid 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.