Triethoxy(vinyl)silane

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Genetic toxicity in vitro:

Gene mutation (Bacterial reverse mutation assay / Ames test, OECD 471): negative with and without activation in all strains tested

Cytogenicity in mammalian cells (CA, OECD 473): negative with and without metabolic activation

Mutagenicity in mammalian cells (MLA, OECD 476): negative with and without metabolic activation

Link to relevant study records

Reference

Reference 1

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:

15 Aug 2001 to 01 Mar 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon (for S. typhimurium strains) and trp operon (for E. coli strain)

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254

Test concentrations with justification for top dose:

Preliminary toxicity study: 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500, and 5000 µg/plate
Mutagenicity test, main study (with and without activation): 50, 150, 500, 1500, and 5000 µg/plate

Vehicle / solvent:

- Vehicle/solvent used: DMSO

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

N-ethyl-N-nitro-N-nitrosoguanidine

benzo(a)pyrene

other: 2-aminoanthracene (2-AA; +S9, 1 µg/plate for TA 100; 2 µg/plate for TA 1535, TA 1537; 10 µg/plate for WP2 uvrA)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)
DURATION
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: 3 plates per experiment, 2 independent experiments

DETERMINATION OF CYTOTOXICITY
- Method: growth of background lawn

Evaluation criteria:

The spontaneous reversion for the solvent control should be within historical control data. The positive controls should demonstrate that the test systems are responsive to known mutagens (induction of at least twice the respective vehicle control).
Positive reaction:
- number of revertants is statistically significantly increased compared to the solvent control in at least one strain
- the increase is reproducible and there is evidence of a dose-response relationship

Statistics:

Dunnett´s method of linear regression (for assessment of dose-response relationship)

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES: No toxicity was observed in the preliminary toxicity test in TA 100 and WP2 uvrA with and without metabolic activation up to the maximum concentration of 5000 µg/plate.

COMPARISON WITH HISTORICAL CONTROL DATA: negative control data were within historical control values

Precipitates: No test material precipitate was observed on the plates at any of the doses tested in either the presence or absence of S9-mix.

Table 1: Results of the first experiment with and without metabolic activation.

With or without S9-Mix	Test substance concentration (µg/plate)	Mean number of revertant colonies per plate (average of 3 plates ± Standard deviation)
		TA 98	TA100	TA1535	TA1537	WP2 uvrA
–	0	23±5	77±7	13±1	7±2	20±1
–	50	15±1	81±7	12±6	6±5	17±4
–	150	16±2	87±2	12±6	9±2	19±6
–	500	14±3	85±10	14±1	8±1	13±3
–	1500	21±3	88±15	12±3	12±3	18±4
–	5000	24±5	88±5	17±4	8±2	18±6
Positive controls, –S9	Name	4-NQO	ENNG	ENNG	9-AA	ENNG
	Concentrations (µg/plate)	0.2	3	5	80	2
	Revertants per plate	91±9	439±29	221±22	2741±121	356±28
+	0	25±1	82±12	10±2	9±2	23±3
+	50	24±5	85±9	10±4	13±6	18±4
+	150	26±4	81±3	11±5	13±1	26±9
+	500	22±7	77±9	12±2	13±3	20±1
+	1500	23±2	88±8	10±3	11±4	19±3
+	5000	24±7	91±10	11±3	11±5	24±6
Positive controls, +S9	Name	BP	2-AA	2-AA	2-AA	2-AA
	Concentrations (µg/plate)	5	1	2	2	10
	Revertants per plate	206±12	825±65	235±7	284±11	801±20

Table 2: Results of the second experiment with and without metabolic activation.

With or without S9-Mix	Test substance concentration (µg/plate)	Mean number of revertant colonies per plate (average of 3 plates ± Standard deviation)
		TA 98	TA100	TA1535	TA1537	WP2 uvrA
–	0	17±3	95±12	15±6	9±6	19±5
–	50	22±2	109±10	13±5	7±4	19±4
–	150	15±4	88±6	18±6	9±4	18±3
–	500	23±5	95±2	14±3	9±1	18±2
–	1500	20±8	104±3	23±5	8±1	22±5
–	5000	24±9	104±2	17±7	8±2	21±3
Positive controls, –S9	Name	4-NQO	ENNG	ENNG	9-AA	ENNG
	Concentrations (µg/plate)	0.2	3	5	80	2
	Revertants per plate	160±11	104±2	187±19	8±2	21±3
+	0	29±6	111±4	18±7	9±4	22±5
+	50	26±4	102±5	22±4	6±1	17±3
+	150	33±5	105±15	14±3	9±4	22±4
+	500	36±6	112±8	18±2	7±3	24±6
+	1500	25±8	103±7	20±6	7±1	19±4
+	5000	30±7	112±9	22±6	10±2	23±
Positive controls, +S9	Name	BP	2-AA	2-AA	2-AA	2-AA
	Concentrations (µg/plate)	5	1	2	2	10
	Revertants per plate	466±28	1152±67	408±28	536±26	909±177

4-NQO: 4-Nitroquinoline-1-oxide

ENNG: N-ethyl-N'-nitro-N-nitrosoguanidine

9-AA: 9-Aminoacridine

2 -AA: 2 -Aminoanthracene

BP: Benzo(a)pyrene

Conclusions:

Under test conditions, no mutagenic effect was observed for the test substance tested up to cytotoxic concentration in any of the test strains in two independent experiments without and with metabolic activation. The test substance is non-mutagenic in test strains used.

Reference 2

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 Jan to 16 Sep 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted equivalent to the appropriate OECD test guideline, and in compliance with GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Target gene:

Not applicable.

Species / strain / cell type:

other: Chinese hamster lung cells

Details on mammalian cell type (if applicable):

- Type and identity of media: MEM medium with HEPES buffer ans Earle´s salts, inclusive 10% FBS and antibiotics

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with phenobarbitone and beta-napthoflavone

Test concentrations with justification for top dose:

6 hour treatment time with and without metabolic activation: 200, 400, 600, 800, 1000, auf 1200 µg/ml
24 hour treatment time without metabolic activation: 80, 160, 320, 480, 640, auf 800 µg/ml
48 hour treatment time without metabolic activation: 40, 80, 160, 320, 480, auf 640 µg/ml

Vehicle / solvent:

- Vehicle/solvent used: Acetone
- Justification for choice of solvent/vehicle: based on the solubility of the test substance

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

6 hour treatment without metabolic activation: 0.1 µg/plate

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

6 hour treatment with metabolic activation: 5 µg/plate

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

24 and 48 hour treatment without metabolic activation Migrated to IUCLID6: 0.05 and 0.025 µg/plate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure time: 6 hours with and without metabolic activation; 24 and 48 hours without metabolic activation.
- Expression time (cells in growth medium): 18 hours subsequent to 6 hour exposure; none following 24 and 48 hour exposure
- Fixation time (start of exposure up to fixation or harvest of cells): short-term exposure: 24 hours; 24 and 48 hour exposure: 24 and 48 hours, respectively.

SPINDLE INHIBITOR (cytogenetic assays): Colcemid (0.1 µg/ml)

STAIN (for cytogenetic assays): Giemsa

NUMBER OF REPLICATIONS: 2 flasks per dose level

NUMBER OF CELLS EVALUATED: 100 per dose level for chromosome aberration

DETERMINATION OF CYTOTOXICITY
- Method: 1000 cells per dose level for mitotic index.

OTHER EXAMINATIONS: Polyploid and endoreduplicated cells were evaluated.

Evaluation criteria:

Positive response: % cells with aberrations, excluding gaps, markedly exceed that seen in the concurrent control, either with or without a clear dose response relationship. For modest increases in aberration frequency a dose response relationship is generally required.

Statistics:

Fisher's exact test was used to analyse the percent aberrant cells. If necessary statistics was applied for assessment of dose response relationship.

Key result

Species / strain:

other: Chinese hamster lung cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

from 600 µg/ml

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: observed at 1300 and 2600 µg/ml
- Other confounding effects: none

RANGE-FINDING/SCREENING STUDIES: metaphases were present at the 650 µg/ml dose levels (6 and 24 h) and at the 325 µg/ml dose level (48 h)
COMPARISON WITH HISTORICAL CONTROL DATA: included in report

ADDITIONAL INFORMATION ON CYTOTOXICITY:
In the 48 h treatment reduction of the mitotic index to>50% was not achieved with the highest concentration tested (640 µg/ml). Based on the results from the 24 h treatment and the assumption of a steep toxicity curve in the range of the used concentration it was concluded that the test substance was tested close to its toxic limit.

Table 1: Summary table of cytogenetic analysis of CHL cells in the absence and presence of metabolic activation.

Treatment µg/ml	S9 Activation	Treatment time	Mean mitotic index	Cells scored	Cells with aberrations
					Numerical       (%)	Structural (%)
Solvent control	-	6	100	200	0	0.5
200	-	6	106	200	0.5	0
400	-	6	105	200	0.5	2.0
600	-	6	65	200	0.5	2.5
800	-	6	0	Toxic	-	-
MMC (0.1)		6	81	200	0	26*
Solvent control	+	6	100	200	0	1.5
200	+	6	91	200	0	1.5
400	+	6	120	200	0	1
600	+	6	34	200	0	2.0
800	+	6	33	200	0	4.5
CP (5)		6	49	100	0	67*
Solvent control	-	24	100	200	0	1.5
480	-	24	129	200	1.5	2.0
640	-	24	100	200	0.5	1.5
800	-	24	42	194	0.5	3.1
MMC (0.05)	-	24	112	150	0	26.7*
Solvent control	-	48	100	200	1	2
320	-	48	90	200	1.5	5.5
480	-	48	126	200	0.5	2
640	-	48	76	200	0	1.5
MMC (0.025)	-	48	84	150	0	26*

*: p<0.001

Conclusions:

Triethoxy(vinyl)silane has been tested for clastogenic potential, in a study which was conducted equivalent to OECD 473 and in compliance with GLP. No evidence of a test related statistically significant increase in the percentage of cells with structural or numerical chromosome aberrations was observed with or without activation in the experiment. Appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for clastogenicity under the conditions of the test.

Reference 3

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 Jan 1990 to 01 Feb 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Deviations:

yes

Remarks:

lacking detailed material/methods section

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Target gene:

TK locus

Species / strain / cell type:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Metabolic activation system:

co-factor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254

Test concentrations with justification for top dose:

Initial compound toxicity test: 0.005, 0.01, 0.05, 0.1, 0.5, 1.0, 5.0, and 10 µl/ml
Cloning data without S9: 0.1, 0.3, 0.4, 0.6, and 0.7 µl/ml
Cloning data with S9: 0.4, 0.6, 0.7, 0.8, and 0.9 µl/ml

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: none given

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

solvent control with DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

3-methylcholanthrene

Remarks:

with metabolic activation system

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

solvent control with DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Remarks:

without metabolic activation system

Details on test system and experimental conditions:

METHOD OF APPLICATION: in suspension

DURATION
- Exposure duration: no data
- Selection time (if incubation with a selection agent): no data
- Expression time (cells in growth medium): 2 days

SELECTION AGENT (mutation assays): trifluorothymidine

NUMBER OF REPLICATIONS: 2 independent experiments per dose

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency; relative total growth

OTHER: Small and large colonies were differentiated, as small colonies are capable to indicate chromosomal mutations.

Evaluation criteria:

Mutation frequency and colony size distribution were assessed, it is assumed by the reviewer that a dose-dependant increase in mutant frequency was evaluated as a positive response.

Statistics:

Mutant frequency, % total growth based on cell concentration and colony size were recorded. There was no statistical treatment of results.

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

1.0 µl/ml

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Table 2: Results of Mammalian Mutagenicity assay (Trial 1) with tester strain L5178Y (mean of 3 plates)

Concentration µl/ml	Mutant* Frequency	Mutant* Frequency	% Total Growth	% Total Growth	Cytotoxicity (yes/no)
	- MA	+ MA	- MA	+ MA
Untreated 1	1.13	1.16	107	105	No
Untreated 2	1.26	1.44	96	106	No
0.1	1.14	1.43	95	105	No
0.1	1.16	1.54	105	102	No
0.3	0.95	1.42	91	75	No
0.3	1.19	1.43	83	90	No
0.4	1.13	1.49	77	68	No
0.4	0.96	1.1	87	65	No
0.6	0.44	0.92	25	34	Yes
0.6	0.53	0.89	42	27	Yes
0.7	0.36	0.67	6	22	Yes
0.7	-	0.91	-	28	Yes
Solvent 1	1.16	1.49	-	-	-
Solvent 2	1.02	1.26	-	-	-
Solvent 3	1.13	1.37	-	-	-
Solvent 4	1.02	1.35	-	-	-
Positive Control	ND	ND	ND	ND	ND

*Per 10⁴surviving cells

solvent control with DMSO

ND: (No data available)

Table 3: Results of Mammalian Mutagenicity assay (Trial 2) with tester strain L5178Y (mean of 3 plates)

Concentration µl/ml	Mutant* Frequency	Mutant* Frequency	% Total Growth	% Total Growth	Cytotoxicity (yes/no)
	- MA	+ MA	- MA	+ MA
Untreated 1	0.34	0.43	113	135	No
Untreated 2	0.3	0.64	116	123	No
0.1	0.38	-	94	-	No
0.1	0.29	-	88	-	No
0.3	0.39	-	91	-	No
0.3	0.33	-	94	-	No
0.4	0.29	0.88	88	90	No
0.4	0.25	0.91	98	72	No
0.6	0.24	0.75	53	56	Yes
0.6	0.35	0.7	68	59	Yes
0.7	0.19	0.84	50	44	Yes
0.7	0.24	0.48	12	63	Yes
0.8	-	0.85	-	27	Yes
0.8	-	0.64	-	29	Yes
0.9	-	0.53	-	24	Yes
0.9	-	0.47	-	31	Yes
Solvent 1	0.41	0.81	-	-	No
Solvent 2	0.42	0.85	-	-	No
Solvent 3	0.31	0.85	-	-	No
Solvent 4	0.28	0.75	-	-	No
Positive Control	3.3	ND	53	ND	No

*Per 10⁴surviving cells

solvent control with DMSO

ND: (No data available)

Positive control substance:  Ethyl Methanesulfonate

Table 4: Results of Mammalian Mutagenicity assay (Trial 3) with tester strain L5178Y (mean of 3 plates)

Concentration µl/ml	Mutant* Frequency	Mutant* Frequency	% Total Growth	% Total Growth	Cytotoxicity (yes/no)
	- MA	+ MA	- MA	+ MA
Untreated 1	ND	0.86	ND	110	No
Untreated 2	ND	0.91	ND	106	No
0.1	ND	1.01	ND	104	No
0.1	ND	1.1	ND	96	No
0.3	ND	0.9	ND	83	No
0.3	ND	0.95	ND	90	No
0.4	ND	0.89	ND	86	No
0.4	ND	0.85	ND	98	No
0.6	ND	0.92	ND	55	Yes
0.6	ND	0.77	ND	70	Yes
0.7	ND	0.85	ND	32	Yes
0.7	ND	0.94	ND	30	Yes
Solvent 1	ND	0.93	ND	-	No
Solvent 2	ND	1	ND	-	No
Solvent 3	ND	0.84	ND	-	No
Solvent 4	ND	1.05	ND	-	No
Positive Control (7.5)	ND	7.1	ND	9	Yes
Positive Control (5)	ND	5.2	ND	40	Yes

*Per 10⁴surviving cells

solvent control with DMSO

ND: (No data available)

Conclusions:

The substance was tested in an in vitro mutagenicity assay in mouse lymphoma L5178Y cells, under GLP and using a method similar to OECD 476. The test substance is non-mutagenic in mouse lymphoma cells under the conditions of the test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Genetic toxicity (mutagenicity) in bacteria in vitro

The test substance was tested in a reliable bacterial mutagenicity study according to OECD 471 and in compliance with GLP. No increase in reversions in comparison with the solvent control was observed in the following Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 uvrA after treatment with up to 5000 µg/plate. Expected results were obtained with the positive controls. It is concluded that the test substance is not mutagenic under the conditions of the test (Safepharm Laboratories Limited, 2002a). Additional available studies also support the conclusion that the test substance is not a bacterial mutagen (Microbiological Associates Inc., 1990; Degussa AG, 2005; Bushy Run Research Center, 1987).

 

Genetic toxicity (cytogenicity) in mammalian cells in vitro

The test substance has been tested according to OECD 473 and under GLP for the induction of chromosome aberrations in mammalian cells. Chinese hamster lung cells were treated in a short term experiment for 6 h (with and without metabolic activation), and in two long term experiments for 24 and 48 h, respectively, without metabolic activation. No evidence of a test related statistically significant increase in the percentage of cells with structural or numerical chromosome aberrations was observed with or without activation in the experiment. Appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for clastogenicity under the conditions of the test (Safepharm Laboratories Limited, 2002b).

 

Genetic toxicity (mutagenicity) in mammalian cells in vitro

The test substance was tested in a reliable in vitro mutagenicity assay in mouse lymphoma L5178Y cells, according to GLP and using a method equivalent to OECD 476. The test substance was tested up to cytotoxic concentration (<31% total growth). No increase of mutant frequency was observed with or without metabolic activation. In conclusion, the test substance is non-mutagenic in mouse lymphoma cells under the conditions of the test (Microbiological Associates Inc., 1991).

 

The available information for the test substance indicates that when tested in vitro, triethoxy(vinyl)silane does not induce mutations in bacterial or mammalian cells and does not cause chromosomal aberration in vitro. Thus, the test substance is not genotoxic under the conditions of the tests.

Justification for classification or non-classification

The available data on genetic toxicity of the test substance do not meet the criteria for classification according to Regulation (EC) No. 1272/2008, and are therefore conclusive but not sufficient for classification.