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Toxicological information

Genetic toxicity: in vitro

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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The tests were conducted to generally acceptable scientific standards, with acceptable restrictions, i.e. no mention of cytotoxic concentrations and positive controls.

Data source

Reference
Reference Type:
publication
Title:
Primary Mutagenicity Screening of Food Additives Currently Used in Japan.
Author:
Ishidate M J R, Sofuni T, Yoshikawa M, Hayashi T, Noshmi T, Sawada M, Matsuoka A
Year:
1984
Bibliographic source:
Fd Chem Toxic 22(8): 623-636

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
(specific positive controls not included)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): sodium citrate
- Substance type: monoconstituent substance
- Analytical purity: 99.6%

Method

Species / strain
Species / strain / cell type:
other: TA 1535, TA 100, TA 98, TA 1537, TA92 and TA 94
Metabolic activation:
with and without
Metabolic activation system:
polychlorinated biphenyl induced rat liver S9
Test concentrations with justification for top dose:
Up to 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: phosphate buffer
- Justification for choice of solvent/vehicle: sample soluble in water
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
other: control was exposed to appropriate solvent or untreated
True negative controls:
no
Positive controls:
other: specific controls not tested, but positive results obtained with some test substances screened
Positive control substance:
other: include Fast Green FCF (with activation), L cysteine monohydrochloride (with and without activation)
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation
DURATION
- Preincubation period: 20 min
- Exposure duration: 48 hours
- Fixation time (start of exposure up to fixation or harvest of cells): 48 hours

NUMBER OF REPLICATIONS: duplicate plates were used

DETERMINATION OF CYTOTOXICITY
- Method: other: not described
Evaluation criteria:
The result was considered positive if the number of colonies found was twice the number in the control (exposed to the appropriate solvent or untreated). If no reasonable dose-response was found, the experiment was repeated using different doses
Statistics:
No statistical analysis is described.

Results and discussion

Test results
Species / strain:
other: TA 1535, TA 100, TA 98, TA 1537, TA92 and TA 94
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:
other: positive results were obtained with some substances tested
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with and without metabolic activation

Sodium dihydrogen citrate has been tested in a bacterial reverse mutation assay similar to OECD 471. No increase in revertant colonies was detected. It was concluded that sodium dihydrogen citrate is not mutagenic under the conditions of this test.