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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

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
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to guideline
Guideline:
JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
Principles of method if other than guideline:
Details of metabolic activation not available from translated report.
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Trimethoxyvinylsilane
EC Number:
220-449-8
EC Name:
Trimethoxyvinylsilane
Cas Number:
2768-02-7
Molecular formula:
C5H12O3Si
IUPAC Name:
trimethoxy(vinyl)silane

Method

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:
Phenobarbital and 5,6-benzoflafove induced rat liver S9
Test concentrations with justification for top dose:
0, 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate
Vehicle / solvent:
- Solvent used: Dimethyl sulfoxide
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide
Remarks:
TA 98, 100, WP2 uvrA without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 1535 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 with activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-amimoanthracene
Remarks:
all strains with activation.
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; preincubation

NUMBER OF REPLICATIONS: 3 plates per dose, experiment repeated

DETERMINATION OF CYTOTOXICITY
- Method: other: reduction in number of revertants
Rationale for test conditions:
Dosage: Without S9 mix: 0, 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate (TA98, TA100, TA1535, TA1537); 0, 312.5, 625, 1250, 2500, and 5000 µg/plate (WP2uvrA) With S9 mix: 0, 312.5, 625, 1250, 2500 and 5000  µg/plate (TA98, TA100, TA1535, WP2uvrA); 
0, 156.3, 312.5, 625, 1250, 2500 and 5000  µg/plate (TA1537)

Metabolic activation: Phenobarbital and 5,6-benzoflavone induced rat liver S9; full detail of S9 mix are included in the Japanese report though they are not given in the English translation

Results and discussion

Test results
Key result
Species / strain:
bacteria, other: Salmonella typhimurium TA100, TA1535, TA1537, TA98; Escherichia coli WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: at 5000 µg/plate for TA100, TA1535, TA1537 and TA98 without S9 mix, and at 5000 µg/plate for TA1537 with S9 mix
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid

Any other information on results incl. tables

Table 1 Experiment 1: without activation (mean of 3 plates)

Concentration µg/plate  TA 100  TA1535  E. coli WP2  TA98  TA1537
 0  105  9  34  17  10
 156.3  113  8   NR  19  8
 312.5  125  8  40  17  10
 625  112  7  32  12  6
 1250  123  14  34  14  7
 2500  115  13  38  18  8
 5000  86  7  31  23  9
 Positive control  521  558  143  425  263
  Cytotoxic*  yes  yes  no  yes  yes

* yes indicates bacterial growth inhibition observed

NT indicates not tested

Table 2 Experiment 1: with activation (mean of 3 plates)

Concentration  µg/plate    TA 100  TA 1535  E coli WP2  TA 98  TA 1537
 0  124  44  42  24  11
 156.3  NT  NT  NT  NT  17
 312.5  1225  12  41  22  15
 625  142  9  46  25  15
 1250  149  8  42  27  9
 2500  148  8  49  35  17
 5000  153  12  41  38  14
Positive control   9007  331  868  405  135
  Cytotoxic*  no  no  no  no  yes

* yes indicates bacterial growth inhibition observed

NT indicates not tested

Applicant's summary and conclusion

Conclusions:
Trimethoxy(vinyl)silane has been tested in a valid study, conducted according to OECD TG 471 and in compliance with GLP, using the preincubation method. No increase in the number of revertants was observed in any of S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 at any concentration up to 5000 µg/plate with or without metabolic activation. The results of the repeat experiment agreed with those of the first experiment. It is concluded that the test substance is negative for the induction of mutations under the conditions of the test.