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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:
14 February 2005 - 24 February 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted in accordance with international guidelines.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
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:
- Name of test material (as cited in study report): SILICON NITRIDE Si3N4
- Physical state: Grey powder
- Analytical purity: >97%
- Lot/batch No.: 2607/04-FS
- Stability under test conditions: At least 1 year
- Storage condition of test material: Dry, in closed container

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium, other: TA97a
Species / strain / cell type:
S. typhimurium TA 98
Species / strain / cell type:
S. typhimurium TA 100
Species / strain / cell type:
S. typhimurium TA 102
Species / strain / cell type:
S. typhimurium TA 1535
Metabolic activation:
with and without
Metabolic activation system:
homogenised livers of female Sprague Dawley rats
Test concentrations with justification for top dose:
Test substance (µg/plate): 62, 185, 556, 1667 and 5000 without external metabolisation and 62, 185, 556, 1667 and 5000 with S9-mix
Control (deionised water): 100µl
Positive control (µg/plate):
Strain: without S9 with S9
TA97a 4NOPD, 10 µg DMBA, 10 µg
TA98 2NF, 2 µg 2AA, 1 µg
TA100 Sodium-azide, 2 µg 2AA, 2 µg
TA102 tBHPO, 50 µg DHA, 50 µg
TA1535 Sodium-azide, 1 µg 2AA, 2 µg

4NOPD: 4-Nitro-o-phenylene-diamine
tBHPO: t-Butyl-hydroperoxide
2AA: 2- Aminoanthracene
DHA: 1,8-Dihydroxy-anthraquinone
DMBA: 7, 12-Dimethylbenz[a]anthracene
2NF: 2-Nitrofluorene
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: deionised water
- Justification for choice of solvent/vehicle: The test substance could be homogeneously suspended in water and water shall be used preferably, according to the guideline.
Controlsopen allclose all
Positive controls:
yes
Positive control substance:
other: 2-Aminoanthracene
Remarks:
with S9Mix
Positive controls:
yes
Positive control substance:
7,12-dimethylbenzanthracene
Remarks:
with S9Mix
Positive controls:
yes
Positive control substance:
other: 1,8-Dihydroxy-anthraquinone
Remarks:
with S9Mix
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
without S9Mix
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
without S9Mix
Positive controls:
yes
Positive control substance:
other: 4-Nitro-o-phenylenediamine
Remarks:
without S9Mix
Positive controls:
yes
Positive control substance:
other: t-Butyl-hydroperoxide
Remarks:
without S9Mix
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 2days

NUMBER OF REPLICATIONS: Triplicate repetitions were run for each dose group in each of the two separate experiments that were
conducted, for the control groups six-fold repetitions were run.

NUMBER OF CELLS EVALUATED: The mean number of viable cells in the overnight-cultures is 2 to 3 x 10x9 cells per mL.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA97a
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Positive controls validity:
valid
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 test results "SILICON NITRIDE Si3N4" is not mutagenic in the Ames test with the strains of Salmonella typhimurium TA97a, TA98, TA100, TA102 and TA1535 with and without an external metabolising system up to 5000µJg/plate, which is the limit concentration for this kind of test.