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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in mammalian cells
Remarks:
Type of genotoxicity: gene mutation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2011-05-23 to 2011-07-22
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Version / remarks:
21 July 1997
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)
Version / remarks:
30 May 2008
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.5300 - In vitro Mammalian Cell Gene Mutation Test
Version / remarks:
August 1998
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
mammalian cell gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Metabolic activation system:
phenobarbital and β-naphthoflavone induced S9 mix
Test concentrations with justification for top dose:
1st Experiment
without S9 mix (4-hour exposure period): 0; 131.3; 262.5; 525.0; 1050.0; 2100.0 μg/mL
with S9 mix (4-hour exposure period): 0; 131.3; 262.5; 525.0; 1050.0; 2100.0 μg/mL

2nd Experiment
without S9 mix (24-hour exposure period): 0; 131.3; 262.5; 525.0; 1050.0; 2100.0 μg/mL
with S9 mix (4-hour exposure period): 0; 250.0; 500.0; 1 000.0; 1500.0; 2100.0 μg/mL
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Culture medium (Ham's F12)
- Justification for choice of solvent/vehicle: Due to the good solubility of the test substance in water, culture medium (Ham's F12) was
used as most suitable vehicle.
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
ethylmethanesulphonate
Remarks:
Migrated to IUCLID6: Without metabolic activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Methylcholanthrene (With metabolic activation)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 4-hour and 24-hour
- Expression time (cells in growth medium): 6 - 8 days
- Selection time: 1 week

SELECTION AGENT: 6-thioguanine (10 μg/mL)
STAIN: Giemsa

NUMBER OF REPLICATIONS: Two independent experiments

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency

Evaluation criteria:
A finding is assessed as positive if the following criteria are met:
• Increase of the corrected mutation frequencies both above the concurrent negative control values and our historical negative control data range.
• Evidence of reproducibility of any increase in mutant frequencies.
• A statistically significant increase in mutant frequencies and the evidence of a doseresponse
relationship.
Isolated increases of mutant frequencies above our historical negative control range or isolated statistically significant increases without a dose-response relationship may indicate a biological effect but are not regarded as sufficient evidence of mutagenicity.
The test substance is considered non-mutagenic according to the following criteria:
• The corrected mutation frequency in the dose groups is not statistically significant
increased above the concurrent negative control and is within our historical negative
control data range.
Statistics:
Due to the clearly negative findings, a statistical evaluation was not carried out.

Results and discussion

Test results
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
not applicable
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Cell morphology:
There were no adverse observations on cell morphology

Treatment conditions:
Osmolarity and pH values were not influenced by test substance treatment. In this study, in the absence and the presence of S9 mix no precipitation in culture medium was observed up to the highest applied test substance concentrations.
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