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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 29 September 1987 to 09 October 1987
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report date:
1987

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
Preincubation method
Deviations:
no
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
422-350-7
EC Name:
-
Cas Number:
5575-48-4
Molecular formula:
C13H30O3Si
IUPAC Name:
Decyltrimethoxysilane
Test material form:
liquid

Method

Target gene:
Histidine (S. typhimurium). Tryptophan (E. coli).
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
A dose finding test was performed.
Final test was performed at 157, 313, 625, 1,250, 2,500, and 5,000 µg/plate with and without metabolic activation for strains TA1535 and WP2.
Final test was performed at 2, 3, 7, 13, 25, 50 and 100 µg/plate with and without metabolic activation for strains TA100, TA98, and TA1537.
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Standard solvent.
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
N-ethyl-N-nitro-N-nitrosoguanidine
benzo(a)pyrene
other: 2-Aminoanthracene
Details on test system and experimental conditions:
DURATION
- Preincubation period: 10 hours
- Exposure duration: 48 hours

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
The test substance is non-mutagenic under the conditions of the test with and without metabolic activation.
Executive summary:

The genotoxicity in bacteria of the test substance was assessed during a study performed according to the pre-incubation method and therefore similar to the OECD Testing Guideline 471.

Strains S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 were used.

A dose-range finding study was performed in order to determine the doses to be used in the final test.

Each bacterium was inoculated in a test tube containing nutrient broth and incubated for 10h at 37°C. Test solution, buffer solution, and bacterium suspension were introduced in a test tube with or without S9-mix and shaken for 20 min in a water bath at 37°C. Agar was added to the mixture and uniformly overlaid on a minimal glucose agar plate. Each plate was incubated for 48h at 37°C and then the number of revertant colonies were colonies.

Negative and positive controls were valid.

No reproducible increase in the number of revertant colonies were observed in presence of the test substance compared with the solvent control group with and without metabolic activation. It can be concluded that the substance was not mutagenic under the conditions of the test.