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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions (missing strain TA 102 to detect crosslinking agents, second independent trial is missing)

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)
Deviations:
yes
Remarks:
no bacterial strains (E.coli WP2 or S.thyphimurium TA102) to detect cross-linking mutagens.
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Pigmentorange Kan 78/1775
- Test substance number: 80/404
- Physical state: solid, orange
- Analytical purity: > 98 %
- Lot/batch No.: Batch 8
- Storage condition of test material: +4°C

Method

Target gene:
his operon
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100
Metabolic activation:
with and without
Metabolic activation system:
cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254
Test concentrations with justification for top dose:
4, 20, 100, 500 and 2500 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: with S-9 mix: 500 µg cyclophosphamide (dissolved in aqua dest.) for the strains TA 100 and TA 1535; 10 µg 2-aminoanthracene (dissolved in DMSO) for the strains TA 100, TA 98, TA 1538, TA 1537 and TA 1535.
Remarks:
with S-9 mix
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: without S-9 mix: 5 µg N-methyl-N-nitro-N-nitroso-guanidine (MNNG) (dissolved in DMSO) for TA 100, TA 98, TA 1535; 10 µg 4-nitro-o-phenylenediamine (dissolved in DMSO) for TA 1538; 100 µg 9-aminoacridine chloride monohydrate (dissolved in DMSO) for TA 1537
Remarks:
without S-9 mix
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation);

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 4

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

OTHER:
- Solubility: Incomplete solubility of the test substance in DMSO from about 500 µg/plate onward.
Evaluation criteria:
In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, 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
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Incomplete solubility of the test substance in DMSO from about 500 µg/plate onward.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Standard plate test (4 - 2500 µg/plate)

Strain

Metabolic activation system

Mean revertants in Controls

Maximum revertant factor

dose dependency

Assessment

TA 98

no

22

1.1

no

negative

yes

41

1.2

no

negative

TA 100

no

155

1.0

no

negative

yes

135

1.0

no

negative

TA 1535

no

12

1.1

no

negative

yes

17

1.4

no

negative

TA 1537

no

7

1.1

no

negative

yes

7

1.4

no

negative

TA 1538

no

17

1.1

no

negative

yes

24

1.3

no

negative

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative