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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
Study period:
no data given
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented guideline study. GLP certificate missing.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Only 2 bacterial strains were tested instead of 4.
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Physical state: solid, yellow powder
- Storage condition of test material: at room temperature

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 98
Additional strain / cell type characteristics:
other: rfa; uvrB; ampicillin resistence (R factor plamid pKM 101); and a modified postreplication DNA repair system, which increases the mutation rate by inducing a defective repair in the DNA
Species / strain / cell type:
S. typhimurium TA 100
Additional strain / cell type characteristics:
other: rfa; uvrB; ampicillin resistence (R factor plamid pKM 101); and a modified postreplication DNA repair system, which increases the mutation rate by inducing a defective repair in the DNA
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
0, 20, 100, 500, 2500 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
Parallel with each experiment with and without S9-mix a solvent control is carried out.
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (2.5 µg), dissolved in DMSO
Remarks:
with metabolic activation; strains TA 98 and TA 100
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
Parallel with each experiment with and without S9-mix a solvent control is carried out.
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-methyl-N'-nitro-N-nitroso-guanidine (5 µg), dissolved in DMSO
Remarks:
without metabilic activation; strain TA 100
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
Parallel with each experiment with and without S9-mix a solvent control is carried out.
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylendiamine (10 µg), dissolved in DMSO
Remarks:
without metabolic activation; strain TA 98
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 20 minutes at 37°C
- Exposure duration: After incubation at 37°C for 48 hours in the dark, the bacterial colonies (his+ revertants) were counted.

NUMBER OF REPLICATIONS: 3 test plates per dose and test or 3 plates per control

DETERMINATION OF CYTOTOXICITY
- Method: Titer determination
In general, the titer is determined only in the experiments with S9-mix both without test substance (solvent only) and after adding the two highest amounts of substance.

No further details are given.
Evaluation criteria:
In general, a substance to be characterised 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
Statistics:
According to the OECD guideline a statistical analysis of the data is not mandatory.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S9-mix or after the addition of metabolic activation system.
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Remarks:
No bacteriotoxic effect was observed.
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S9-mix or after the addition of metabolic activation system.
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Remarks:
No bacteriotoxic effect was observed.
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
Solubility of the test substance: No precipitation of the test substance was found.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

According to the results of the present study, the test substance Sicocer F Gelb 2214 is not mutagenic in the Ames test under the experimental conditions chosen here.