Silicic acid, ethyl ester

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

Mutagenicity test conducted for the given test chemical.

Author:

Seifried et al

Year:

2006

Bibliographic source:

Chem. Res. Toxicol.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

The Ames salmonella typhimurium mutagenicity test was conducted for the given test chemical.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Tetraethyl orthosilicate

EC Number:

201-083-8

EC Name:

Tetraethyl orthosilicate

Cas Number:

78-10-4

Molecular formula:

C8H20O4Si

IUPAC Name:

Tetraethyl silicate

Test material form:

liquid

Details on test material:

- Name of test material (as cited in study report): Ethyl silicate- Molecular formula : C8H20O4Si- Molecular weight : 208.328 g/mol- Smiles notation: [Si](OCC)(OCC)(OCC)OCC - InChI: 1S/C8H20O4Si/c1-5-9-13(10-6-2,11-7-3)12-8-4/h5-8H2,1-4H3- Substance type: Organic - Physical state: Liquid

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not applicable

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

Liver S9 homogenate was prepared from male Sprague-Dawley rats and Syrian golden hamsters that had been injected with Aroclor 1254 at 500 mg/kg body weight.

Test concentrations with justification for top dose:

100- 10000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Yes, no detailed data available
- Justification for choice of solvent/vehicle: No data available

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: No data available
- Exposure duration: 48 h
- Expression time (cells in growth medium): 48 h
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available

SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available

STAIN (for cytogenetic assays): No data available

NUMBER OF REPLICATIONS: Triplicate

NUMBER OF CELLS EVALUATED: No data available

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data available

OTHER EXAMINATIONS:
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other: No data available

OTHER: No data available

Rationale for test conditions:

No data

Evaluation criteria:

The criteria used to evaluate a test were as follows: for a test article to be considered positive, it had to induce at least a doubling (TA98, TA100, and TA1535) in the mean number of revertants per plate of at least one tester strain. This increase in the mean revertants per plate had to be accompanied by a dose response to increasing concentrations of the test chemical. If the study showed a dose response with a less than 3-fold increase on TA1537 or TA1538, the response had to be confirmed in a repeat experiment.

Statistics:

No data available

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

No data available

Remarks on result:

other: No mutagenic potential

Applicant's summary and conclusion

Conclusions:

The given test chemical failed to induce mutation in the Salmonella typhimurium TA98, TA100, TA1535, TA1537, and TA1538 both in the presence and absence of S9 activation system and hence is not likely to be a gene mutant.

Executive summary:

The Ames salmonella typhimurium mutagenicity test was conducted for the given test chemical to evaluate its gene toxic effects when exposed to Salmonella typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 in the presence and absence of S9 metabolic activation system Liver S9 homogenate, which was prepared from male Sprague-Dawley rats and Syrian golden hamsters that had been injected with Aroclor 1254 at 500 mg/kg body weight with dose concentration of 100-10000 µg/plate in plate incorporation assay. Based on the preliminary study conducted, the test compound was used at a five dose level from 100- 10000 µg/plate. For a test article to be considered positive, it had to induce at least a doubling (TA98, TA100, and TA1535) in the mean number of revertants per plate of at least one tester strain. This increase in the mean revertants per plate had to be accompanied by a dose response to increasing concentrations of the test chemical. If the study showed a dose response with a less than 3-fold increase on TA1537 or TA1538, the response had to be confirmed in a repeat experiment. The given test chemical failed to induce mutation in the Salmonella typhimurium TA98, TA100, TA1535, TA1537, and TA1538 both in the presence and absence of S9 activation system and hence is not likely to be a gene mutant.