Silane, triethyl[[4-(triethylsilyl)-3-butyn-1-yl]oxy]-

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

One key study: Evaluation of the mutagenic activity of Bis-Tes (dried) in the Salmonella typhimurium reverse mutation assay and the Escherichia coli reverse mutation assay.

Link to relevant study records

Reference

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:

2014-06-16 to 2014-07-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted according to OECD method and in accordance with GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

Four histidine-requiring strains (Salmonella typhimurium (TA1535, TA1537, TA98 and TA100)) and one tryptophan-requiring strain (Escherichia coli (WP2uvrA).

Species / strain / cell type:

other: Salmonella typhimurium: TA1535, TA1537, TA98, TA100. Escherchia coli WP2uvrA.

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix (rat liver S9-mix induced by Aroclor 1254)

Test concentrations with justification for top dose:

For genotoxicity experiment concentrations (with & without metabolic activation) used: 5000 ug/plate for plate incorporation method.

Vehicle / solvent:

Solvent- ethanol

Untreated negative controls:

yes

Remarks:

Ethanol

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Remarks:

With metabolic activation

Positive control substance:

other: 2-aminoanthracene

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Without metabolic activation

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

Without metabolic activation

Migrated to IUCLID6: 2.5 ug/plate (TA98) without s-9

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Without metabolic activation

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

Without metabolic activation

Details on test system and experimental conditions:

Precipitation of Bis-Tes (dried) on the plates was observed at the start and at the end of the incubation
period at concentrations of 1600 and 5000 µg/plate. Except in the tester strains TA1535, TA1537 and
TA100 in the absence of S9-mix, in which no precipitation of the test substance was observed at
1600 µg/plate.

There was no reduction of the bacterial background lawn and no
biologically relevant decrease in the number of revertants at any of the concentrations tested in all
tester strains in the absence and presence of S9-mix.

In strain TA1537 (presence of S9-mix), a fluctuation in the number of revertant colonies below the
laboratory historical control data range was observed at the mid dose of 164 µg/plate. However, since
no dose-relationship was observed, the reduction is not considered to be caused by toxicity of the test
substance

Evaluation criteria:

A test substance is considered negative (not mutagenic) in the test if:
a) The total number of revertants in tester strain TA100 is not greater than two (2) times the
concurrent control, and the total number of revertants in tester strains TA1535, TA1537, TA98 or
WP2uvrA is not greater than three (3) times the concurrent vehicle control.
b) The negative response should be reproducible in at least one independently repeated experiment.
A test substance is considered positive (mutagenic) in the test if:
a) The total number of revertants in tester strain TA100 is greater than two (2) times the concurrent
control, or the total number of revertants in tester strains TA1535, TA1537, TA98 or WP2uvrA is
greater than three (3) times the concurrent vehicle control.
b) In case a repeat experiment is performed when a positive response is observed in one of the tester
strains, the positive response should be reproducible in at least one independently repeated
experiment.

Statistics:

Mean and standard deviation of the plate counts for each treatment were determined.

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

other: yes. Negative control values were within the laboratory historical control data ranges, except for TA1535 in the presence of S9-mix (1st experiment). Since this value was just outside the limit of the range, the validity of the test was not affected.

Positive controls validity:

valid

Additional information on results:

There were no deviations from standard operating procedures that affected the integrity of the study.

Bis-Tes (dried) did not induce a significant dose-related increase in the number of revertant (His+
)
colonies in each of the four tester strains (TA1535, TA1537, TA98 and TA100) and in the number of
revertant (Trp+
) colonies in tester strain WP2uvrA both in the absence and presence of S9-metabolic
activation. These results were confirmed in an independently repeated experiment.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative

Based on the results of this study it is concluded that Bis-Tes (dried) is not mutagenic in the
Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.

Executive summary:

No increase in the number of revertants was observed upon treatment with Bis-Tes (dried) under all

conditions tested. Bis-Tes (dried) is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

Based on the results of this study it is concluded that Bis-Tes (dried) is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.