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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:
1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
(outdated version of guideline, only four strains tested)

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)
Version / remarks:
adopted May 26, 1983
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Batch T05003
Expiry date 17 June 2000
Stability in vehicle: Dimethylsulphoxide: at least 96 h
Specific details on test material used for the study:
- Lot/batch No.: T05003
- Expiration date of the lot/batch: 17 June 2000
- Stability under test conditions: Stable in dimethylsulphoxide for at least 96 h
- Storage condition of test material: at room temperature in the dark

Method

Target gene:
his operon
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254-induced rat liver S9
Test concentrations with justification for top dose:
3, 10, 30, 100, 333, 1000, 3330 and 5000 µg/plate for TA 100
1, 3, 10, 33 and 100 µg/plate for other strains
Vehicle / solvent:
DMSO
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene for all strains
Remarks:
with metabolic activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide for TA 1535, 9-aminoacridine for TA 1537, daunomycine for TA98 and methylmethanesulfonate for TA 100
Remarks:
without metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
Evaluation criteria:
A test substance is considered positive (mutagenic) in the test if:
a) It induces at least a 2-fold, dose related increase in the number of revertants with respect to the number induced by the solvent control in any of the tester strains, either with or without metabolic activation. However, any mean plate count of less than 20 is considered to be not significant.
b) The positive response should be reproducible in at least one independently repeated experiment.
Statistics:
Not needed.

Results and discussion

Test results
Key result
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 98 and 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:
not examined
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
negative