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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 based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
2010-01-13 - 2010-01-13
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535
Additional strain / cell type characteristics:
other: his G46, uvrb, rfa
Species / strain / cell type:
S. typhimurium TA 97
Additional strain / cell type characteristics:
other: hisD6610, uvrB, pKM 101, rfa
Species / strain / cell type:
S. typhimurium TA 98
Additional strain / cell type characteristics:
other: hisD3052, uvrB, pKM 101, rfa
Species / strain / cell type:
S. typhimurium TA 100
Additional strain / cell type characteristics:
other: hisG46, uvrb, pKM101, rfa
Species / strain / cell type:
S. typhimurium TA 102
Additional strain / cell type characteristics:
other: hisG428, pKM 101, rfa
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
Plate-incorporation method: 50, 151, 500, 1510, 4990 µg/plate
Pre-incubation method: 319, 643, 1261, 2506, 5031 µg/plate
Vehicle / solvent:
sterile water
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
other: 4-Nitro-1,2-phenylene diamine
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
other: 2-Amino-anthracene
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
benzo(a)pyrene

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: strain/cell type: hisD6610, uvrB, pKM 101, rfa
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

1.1       First Experiment

1.1.1      Confirmation of the Criteria

The treatments for the sterility control and the determination of the titre did not show any inconsistencies. The determined values for the spontaneous revertants of the negative controls were in the normal range of the test laboratory (historical data of the laboratory). All positive controls (diagnostic mutagenes) showed mutagenic effects with and without metabolic activation.

1.1.2      Solubility and Toxicity

The test item was not sufficiently soluble in the accepted solvents for the Ames-test. Therefore, suspensions were prepared. The test item was autoclaved and suspended in deionised water.

No signs of toxicity towards the tested strains could be observed. The background lawn was visible and the number of revertant colonies was not reduced.

1.1.3      Mutagenicity

No significant increase of the number of revertant colonies in the treatments with and without metabolic activation could be observed. No concentration-related increase over the tested range was found.

 

Therefore the test item is stated as not mutagenic under the test conditions.

 

To verify this result, a second experiment was performed using the pre-incubation method.

1.2       Second Experiment

1.2.1      Confirmation of the Criteria

The treatments for the sterility control and the determination of the titre did not show any inconsistencies. The determined values for the spontaneous revertants of the negative controls were in the normal range of the test laboratory. All positive controls showed mutagenic effects with and without metabolic activation.

1.2.2      Solubility and Toxicity

The test item was not sufficiently soluble in the accepted solvents for the Ames-test. Therefore, suspensions were prepared. The test item was autoclaved and suspended in deionised water.

No signs of toxicity towards the tested strains could be observed. The background lawn was visible and the number of revertant colonies was not significantly reduced.

1.2.3      Mutagenicity

No significant increase of the number of revertant colonies in the treatments with and without metabolic activation was observed. No concentration-related increase over the tested range was found.

Therefore the test item is stated as not mutagenic under the test conditions.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test item Spinel is not mutagenic under the conditions of the test. Applying read-across it can be concluded that Pleonaste is not mutagenic in the Bacterial Reverse Mutation Test.
Executive summary:

Justification for read-across:

Spinel type minerals all have a spinel crystal structure, no water solubility and high melting points. Their behaviour in water and biological systems is dominated by their insolubility and missing bioavailability. They constitute in general practically inert materials also regard to their content of heavy metals. Thus, they to not contribute to any ecological hazards. They are also not bioavailable in vivo, which was confirmed by solubility tests in surfactant and stomach/small intestine fluids. The Spinel type minerals are not skin irritating and not eye irritating in the conducted in vitro tests. In addition, there is no sensitizing concern for the Pleonaste metal constituents Fe and Mg.

Physico-chemical properties of Spinel and Pleonaste:

  Spinel  Pleonaste 
density (g/cm3)  3.55  3.82 
melting-point (degree C) 2,135  > 1,650 
water-solubility  insoluble   insoluble
bioavailability in the digestive tract not bioavailable  not bioavailable 
bioavailability in the lung   not bioavailable

 not bioavailable

 crystal structure  spinel lattice  spinel lattice

The test item Spinel did not show mutagenic effects in both experiments. The number of revertant colonies was not increased in comparison with the spontaneous revertants (solvent only).

Cytotoxicity of the test item was not detected. The background lawn was visible and the number of revertants was not significantly decreased.

Therefore it can be stated, that under the test conditions, the test item Spinel is not mutagenic in the Bacterial Reverse Mutation Test using Salmonella typhimurium, strainsTA 97a, TA 98, TA 100, TA 102 and TA 1535.

Applying read-across it can be concluded that Pleonaste is not mutagenic in the Bacterial Reverse Mutation Test.