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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:
experimental study
Adequacy of study:
supporting study
Study period:
1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: comparable to guideline study with acceptable restrictions; the applied strains of bacteria may not detect certain oxidising mutagens, cross-linking agents; the negative result was not repeated

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
- TA 102 or E.coli WP2 strains are not included; negative results were not repeated
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
Histidine gene locus
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 1535, TA 100, TA 1537, TA 1538 and TA 98
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male Wistar rat liver S9 mix
Test concentrations with justification for top dose:
0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1 , and 2.5mg/plate (6/7 concentrations per strain in the presence and absence of S9 mix); the initial experiments with the tester strains TA1538 and TA98 had to be repeated with lower concentrations in order to obtain an appropriate concentration range;
testing was performed up to toxicity and well into the precipitation range








Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
sodium azide
benzo(a)pyrene
cyclophosphamide
other: anthracen-2-amine

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA 1535, TA 100, TA 1537, TA 1538 and TA 98
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
growth inhibition of the background lawn was observed in all strains generally starting at 0.1 mg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium, other: TA 1535, TA 100, TA 1537, TA 1538 and TA 98
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
growth inhibition of the background lawn was observed in all strains generally starting at 0.5 mg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Precipitates were found in the agar starting at 0.1 mg/plate

Applicant's summary and conclusion

Executive summary:

The mutagenic potential of the test substance was evaluated in a Salmonella/microsome test with the S. typhimurium strains TA 98, TA 100, TA 1535, 1538 and TA 1537 in the presence and absence of S9 mix in a test protocol generally following OECD TG 471. Deviations from guideline were the absence of a strain which detects cross-linking mutagens (e.g. TA 102) and that the negative result was not verified. Evaluation of the data indicates that the test substance is not a mutagen in the Ames Salmonella/microsome test.