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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1981
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report Date:
1981

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Vat Blue 20

Method

Target gene:
Salmonella typhimurium histidine (his) reversion system
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
rat liver S9
Test concentrations with justification for top dose:
0, 0.16, 0.8, 4, 20, 100 µg/plate
The test item is not soluble in water or organic solvents. Concentrations higher than 100 µg(plate could hence not be achieved. Precipitations were observed at 20 and 100 µg/plate.
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
other: 2-aminoanthracene, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitro-o-phenylenediamine
Details on test system and experimental conditions:
The test substance was tested in the standard plate test with and without S-9 mix in Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100 at
0, 0.16, 0.8, 4, 20, 100 µg/plate

The test substance was dissolved in DMSO and every concentration was tested in tetraplicate.
Evaluation criteria:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
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, but tested up to precipitating concentrations
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, but tested up to precipitating concentrations
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:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Incomplete solubility of the test substance in DMSO from 20 µg/plate onwards

Applicant's summary and conclusion

Conclusions:
The test item was not mutagenic in the bacteria reverse mutation assay
Executive summary:

The test item was tested in the standard plate incorporation test in Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100 at concentrations from 0.16 to 100 µg/plate both in the presence and absence of metabolic activation. No cytotoxicity was observed at any concentration. At concentrations of 20 µg/plate and above, precipitation of the test stubstance was observed. An increase in the number of revertant colonies could not be observed up to the highest dose of 100 µg/plate. Vat Blue 20 is thus not mutagenic in the Ames test under the experimental conditions chosen.