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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:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Justification for type of information:
Data is from study report

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Refer below principle
Principles of method if other than guideline:
Ames test was performed to determine the mutagenic nature of the test chemical.
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name of test material (as cited in study report): 1,2-benzisothiazol-3(2H)-one 1,1-dioxide, sodium salt
- Substance type: organic
- Physical state: solid

Method

Target gene:
Histidine
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell type (if applicable):
Not applicable
Additional strain / cell type characteristics:
not specified
Cytokinesis block (if used):
No data
Metabolic activation:
with and without
Metabolic activation system:
S-9 Mix (from liver homogenate of Aroclor 1254 treated rats)
Test concentrations with justification for top dose:
With S9 mix: 0, 3.15, 10, 31.5, 100, 315, 1000 or 3150 µg/plate
Without S9 mix: 0, 100, 315, 954 or 3150 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO (Dimethylsulphoxide)
- Justification for choice of solvent/vehicle: The test chemical was soluble in DMSO but its role as solvent in unknown
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: N-methyl- N'- nitro- N- nitrosoguanidine and benzo(a)pyrene- 4,5-oxide
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)
- Cell density at seeding (if applicable): No data

DURATION
- Preincubation period: No data
- Exposure duration: 2-3 days
- Expression time (cells in growth medium): 2-3 days
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data

SPINDLE INHIBITOR (cytogenetic assays): No data

STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: No data

METHODS OF SLIDE PREPARATION AND STAINING TECHNIQUE USED: No data

NUMBER OF CELLS EVALUATED: No data

NUMBER OF METAPHASE SPREADS ANALYSED PER DOSE (if in vitro cytogenicity study in mammalian cells): No data

CRITERIA FOR MICRONUCLEUS IDENTIFICATION: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data
- Any supplementary information relevant to cytotoxicity: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Methods, such as kinetochore antibody binding, to characterize whether micronuclei contain whole or fragmented chromosomes (if applicable): No data

- OTHER: No data
Rationale for test conditions:
No data
Evaluation criteria:
Colonies with his+ revertants were counted.
Statistics:
No data

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
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:
valid
Additional information on results:
No data
Remarks on result:
other: No mutagenic potential

Applicant's summary and conclusion

Conclusions:
The test chemical did not induce gene mutation in S. typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 with and without S9 liver fractions and hence is not likely to classify as a gene mutant in vitro.
Executive summary:

Ames test was performed to determine the mutagenic nature of the test chemical. The test chemical was dissolved in Dimethylsulfoxide (DMSO) at a dosage of 0, 3.15, 10, 31.5, 100, 315, 1000 or 3150 mg/plate (with S9) or 0, 100, 315, 945 or 3150 mg/plate (without S9). The test compound was dissolved in the incubation mixture up to the highest concentration. No indications of toxicity, such as a reduced his-background lawn, were observed. The test chemical did not induce gene mutation in S. typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 with and without S9 liver fractions and hence is not likely to classify as a gene mutant in vitro.