Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Gene mutation (Bacterial reverse mutation assay / Ames test): negative with and without activation in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 Escherichia coli WP2 (OECD TG 471) (Dow Corning Corporation, 2011b).
Cytogenicity in mammalian cells: negative with and without activation in cultured human lymphocytes (OECD TG 473) (Dow Corning Corporation, 2011c).
Mutagenicity in mammalian cells: negative with and without activation in L5178Y mouse lymphoma cells (OECD TG 476) (Bioservice, 2012).

Link to relevant study records

Referenceopen allclose all

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25.08.2011 - 15.09.2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Qualifier:
according to
Guideline:
JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
Version / remarks:
Kanpoan No.287
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay
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:
Phenobarbitol/beta-naphthoflavone induced rat liver S9
Test concentrations with justification for top dose:
3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Acetone
- Justification for choice of solvent/vehicle: the solvent was requested by the sponsor.
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Acetone
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 1535, TA100 without metabolic activation 10 µg/plate
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Acetone
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylene-diamine 10 µg/plate TA98 and 50 µg/plate TA1537
Remarks:
TA1537, TA98 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Acetone
True negative controls:
no
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
WP2 uvrA without metabolic activation 3 µl/plate
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Acetone
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene 2.5 µg/plate TA1535, TA1537, TA98, TA100 and 10 µg/plate WP2 uvrA
Remarks:
TA1535, TA1537, TA98, TA100, WP2 uvrA with metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

ACTIVATION: S9 mix contained glucose-6-phosphate and NADP as co-factors. The amount of S9 supernatant was 10% v/v in the S9 mix. 0.5 ml S9 was added to test solution, bacterial suspension and top agar giving a final concentration in the cultures of approximately 2% S9.

DURATION
- Preincubation period: 60 minutes at 37C
- Exposure duration: 72 hours

SELECTION AGENT (mutation assays): histidine deficient agar

NUMBER OF REPLICATIONS: triplicate plates, pre-experiment for toxicity and experiment 1 used plate incorporation, the test was repeated using pre-incubation.

DETERMINATION OF CYTOTOXICITY
- Method: other: condition of background lawn


Evaluation criteria:
A test item is considered as a mutagen if a biologically relevant increase in the mean number of revertant colonies exceeding the threshold of twice (strains TA98, TA100 and WP2 uvrA) or thrice (strains TA1535 and TA1537) the mean colony count of the corresponding solvent control is observed. A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration. An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second experiment.
Statistics:
No statistical evaluation of the data was required.
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and 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:
valid
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:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS

- Precipitation: No precipitation was observed


ADDITIONAL INFORMATION ON CYTOTOXICITY: Cytotoxicity was not evident at any concentrations

Table 1: Experiment 1 - Mean revertant colony counts

 

TA 1535

TA 1537

TA 98

TA 100

WP2 uvrA

Concentration (µg/plate)

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Solvent control

14

21

15

25

33

38

126

130

47

49

Negative control

16

17

17

21

37

54

120

127

44

49

3

12

21

16

24

32

41

123

120

52

49

10

13

18

14

24

34

37

117

131

40

56

33

15

21

18

21

36

37

129

105

44

49

100

13

24

16

24

39

39

139

131

40

53

333

15

18

18

19

38

29

134

134

47

48

1000

14

16

16

15

38

23

142

135

51

46

2500

18

17

18

16

38

23

127

124

45

44

5000

14

18

17

15

29

18

129

119

39

31

Positive control

1536

313

71

388

326

1266

1791

2270

956

227

 

  Table 2: Experiment 2 Mean revertant colony counts 

 

 

TA 1535

TA 1537

TA 98

TA 100

WP2 uvrA

Concentration (µg/plate)

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Solvent control

16

21

22

26

37

37

132

139

49

63

Negative control

18

16

24

28

41

45

142

143

52

64

3

NA

19

NA

26

NA

41

NA

159

NA

58

10

NA

21

NA

24

NA

39

NA

162

NA

55

33

18

24

21

26

31

44

124

124

50

61

100

16

21

24

30

33

40

140

161

58

53

333

17

18

24

19

37

35

134

150

51

53

1000

17

15

21

19

33

29

155

145

58

58

2500

15

16

20

17

30

31

156

127

56

37

5000

17

16

24

16

38

29

155

114

57

42

Positive control

1780

318

118

266

329

1655

1782

1602

643

261

Conclusions:
3,3-Bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane has been tested for mutagenicity to bacteria, in a study which was conducted according to OECD Test Guideline 471 and in compliance with GLP. No evidence of a test substance related increase in the number of revertant colonies was observed with or without metabolic activation in the pre-experiment for toxicity or the initial assay using the plate incorporation method using S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2. The result was confirmed the repeat preincubation experiment. Appropriate positive, negative and solvent controls were included and gave expected results. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.
Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011-07-28 - 2011-09-30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
GLP compliance:
yes (incl. certificate)
Type of assay:
in vitro mammalian chromosome aberration test
Species / strain / cell type:
lymphocytes: peripheral human lymphocytes
Details on mammalian cell type (if applicable):
Blood cultures were set up in bulk within 24 hours of collection in 75 cm flasks. Culture medium was DMEM:F12 ( Dulbeccos's modified eagle medium)/Hams F:12; mixed 1:1. Medium included 15mM HEPES and 200 mM L-glutamine. Also added was 10,000 U/ml penicillin and 10,000 µg/ml streptomycin, Phytohemagglutinin - 3 µg/ml, 10% FBS (foetal bovine serum), heparin 25,000 USP-U/ml. All incubations were at 37°C in humified atmosphere with 5.5% CO2.
Metabolic activation:
with and without
Metabolic activation system:
Phenobarbital and beta-naphthoflavone induced rat liver S9
Test concentrations with justification for top dose:
0.01, 0.02, 0.04, 0.08, 0.16, 0.3, 0.6, 1.3, 2.5 and 5.0 µl/ml
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Acetone
- Justification for choice of solvent/vehicle: Solvent chosen due to its solubility properties and its relative non-toxicity to the cell cultures.
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
ethylmethanesulphonate
Remarks:
without metabolic activation exp 1: 825 µg/ml exp 2: 660 µg/ml
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
Remarks:
with metabolic activation exp 1 and 2: 7.5 µg/ml
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium

ACTIVATION: S9 mix contained glucose-6-phosphate and NADP as co-factors

DURATION

- Exposure duration: Exp 1 - 4 hours with and without S9. Exp 2 - 4 hours with S9 mix and 22 hours without S9
- Expression time (cells in growth medium):94 hours
- Fixation time (start of exposure up to fixation or harvest of cells): 22 hours

SPINDLE INHIBITOR (cytogenetic assays): colcemid
STAIN (for cytogenetic assays): Giemsa

NUMBER OF REPLICATIONS: duplicate flasks, test repeated

NUMBER OF CELLS EVALUATED: 200 metaphases scored for chromosome aberrations per dose group, 2000 cells per dose group were counted for determination of the mitotic index.

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

OTHER EXAMINATIONS:
- Determination of polyploidy: yes
- Determination of endoreplication: no
Evaluation criteria:
The test item is classified as mutagenic if the number of induced structural chromosome aberrations is not within the range of the historical control data and a concentration related increase or a significant increase in the number of structural chromosome aberrations is observed.
Statistics:
Fisher's exact test
Key result
Species / strain:
lymphocytes: peripheral human lymphocytes
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: no relevant influence was observed
- Effects of osmolality: slightly decreased at the highest concentration
- Precipitation: none observed

COMPARISON WITH HISTORICAL CONTROL DATA: aberration rates of cells after treatment were close to the range of the solvent control values and within the range of the historical data

Summary of results from Experiments I and II with and without metabolic activation

Experiment

Preparation interval (hrs)

Dose level µl/ml

% Polyploid cells

MI* in % of control

% Aberrant cells

Incl gaps

Excl gaps

With exchanges

Exposure period 4 hours without S9 mix

I

22

Solvent control

0.2

100.00

1.5

1.0

0.0

Positive control

-

116.4*

13.0

10.0

1.0

0.3

0.0

116.4

0.5

0.5

0.0

1.3 PS

0.0

82.5

1.0

0.5

0.0

2.5 PS

0.0

98.8

3.0

2.5

0.5

5.0 PS

0.0

84.2

1.0

1.0

0.0

Exposure period 22 hours without S9 mix

II

22

Solvent control

0.0

100.0

2.5

2.0

0.5

Positive control

-

51.5

13.5

12.5

1.5

0.3

0.0

97.5

1.0

1.0

0.0

1.3 PS

0.4

92.8

0.5

0.5

0.0

2.5 PS

0.2

92.0

1.5

1.5

0.0

5.0 PS

0.0

89.9

0.0

0.0

0.0

Exposure period 4 hours with S9 mix

I

22

Solvent control

0.0

100.0

0.5

0.5

0.0

Positive control

-

65.9

10.0

8.5

0.5

0.3

0.2

87.0

1.5

1.0

0.0

1.3 PS

0.0

86.2

1.0

0.5

0.0

2.5 PS

0.2

91.3

1.5

1.5

0.0

5.0 PS

0.2

97.8

2.0

2.0

0.0

Exposure period 4 hours with S9 mix

II

22

Solvent control

0.0

100.0

2.5

2.5

0.0

Positive control

-

46.8

16.5

16.5

2.0

0.3

0.0

98.2

2.0

1.5

0.5

1.3 PS

0.4

80.1

1.0

1.0

0.0

2.5 PS

0.2

100.0

0.5

0.5

0.0

5.0 PS

0.0

111.7

0.5

0.5

0.0

MI = mitotic indices

PS = Phase separation was observed

* It is noted by the reviewer that this positive control does not exhibit mitotic inhibition, and that the value is the same as that for the lowest test concentration in the row below.

Conclusions:
3,3-Bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane has been tested in an in vitro chromosome aberration assay in peripheral human lymphocytes, conducted according to OECD Test Guideline 473 and in compliance with GLP. No evidence of a test substance related increase in chromosome aberrations was observed with or without metabolic activation in the initial or the repeat experiment. Appropriate positive and solvent controls were included and gave expected results. It is concluded that the test substance is negative for cytogenicity under the conditions of the test.
Endpoint:
in vitro gene mutation study in mammalian cells
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011-11-08 to 2012-01-04
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.5300 - In vitro Mammalian Cell Gene Mutation Test
Deviations:
no
Qualifier:
according to
Guideline:
other: IWGT Recommendations
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
(Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, Germany)
Type of assay:
mammalian cell gene mutation assay
Target gene:
Thymidine kinase
Species / strain / cell type:
mouse lymphoma L5178Y cells
Details on mammalian cell type (if applicable):
- Type and identity of media: RPMI
- Properly maintained: Yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically "cleansed" against high spontaneous background: yes
Metabolic activation:
with and without
Metabolic activation system:
Phenobarbital and ß-Naphthoflavone-induced rat liver S9
Test concentrations with justification for top dose:
Pre-expt I: 0.1, 0.5, 2.5, 5.0, 7.5 and 10.0 mM (+/-S9); Pre-expt II: 2.5, 5.0, 7.5 and 10.0 mM (24 h -S9);
Expt I: 0.5, 1.0, 2.0, 4.0, 5.0, 7.0, 8.0 and 10.0 mM (+S9), 0.25, 1.0, 2.0, 4.0, 7.0, 8.0, 9.0 and 10.0 mM (-S9);
Expt II: 0.75, 1.5, 3.5, 6.5, 7.5, 8.5, 9.5 and 10.0 mM (+S9), 0.1, 0.5, 1.0, 2.0, 4.0, 7.0, 9.0 and 10.0 mM (-S9)




Vehicle / solvent:
The test item was soluble in acetone (final concentration of 0.5% solvent v/v).
The solvent was compatible with the survival of the cells of the S9 activity.
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
with metabolic activation 2.5 µg/mL
Positive control substance:
ethylmethanesulphonate
Remarks:
without metabolic activation 200 µg/mL and 300 µg/mL
Positive control substance:
methylmethanesulfonate
Remarks:
without metabolic activation 10 µg/mL
Details on test system and experimental conditions:
METHOD OF APPLICATION: suspended / dissolved in medium
DURATION: 4 h (short-term exposure), 24 h (long-term exposure)
Expression time (cells in growth medium): 48 h
Selection time (if incubation with selection agent): about 14 days

SELECTION AGENT ( mutation assay) 5 µg/mL trifluorothymidine
NUMBER OF REPLICATIONS: two separate experiments (I+II) with single exposure; cells were seeded in 4 plates and evaluated
NUMBER OF CELLS SEEDED: 2000 cells per well
DETERMINATION OF CYTOTOXICITY: relative total growth (RTG)

METABOLIC ACTIVATION: S9 mix included glucose-6-phosphate and NADP, and sufficient S9 to give a protein concentration of 0.75 mg/ml in the cultures.
Evaluation criteria:
The test item is considered mutagenic if following criteria are met:
-The induced mutant frequency meets or exceeds the Global Evaluation factor (GEF) of 126 per 10^6 cells
- A dose-dependent increase in mutant frequency is detected.

Besides, combined with a positive effect in the mutant frequency, an increased occurrence of small colonies (≥40% of total colonies) is an indication for potential clastogenic effects and/or chromosomal aberrations.
According to the OECD guideline, the biological relevance is considered first for the interpretation of results. Statistical methods might be used as an aid in evaluation the test result.
A test item is considered to be negative if the induced mutant frequency is below the GEF and the trend test is negative.

Statistics:
The non-parametric Mann-Whitney test is applied to the mutation data to prove the dose groups for any significant difference in mutant frequency compared to the negative /solvent controls.
Key result
Species / strain:
mouse lymphoma L5178Y cells
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Pre-experiment toxicity with and without metabolic activation

Concentration (mM)

Number of cells 4 h after treatment

Number of cells 24 h after treatment

Number of cells 48 h after treatment

SGa

RSGb

 (%)

 

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

Negative control

315000

308000

1050000

500000

1280000

226000

13.4

11.3

82.2

94.0

Negative control

328000

294000

966000

513000

1600000

223000

15.5

11.4

94.5

95.2

Solvent control

311000

309000

9850000

658000

1630000

179000

16.1

11.8

100.0

100.0

Solvent control

328000

329000

1010000

632000

1650000

194000

16.7

12.3

0.1

290000

249000

1050000

697000

1370000

171000

17.8

11.9

108.9

99.2

0.5

327000

290000

1050000

821000

1510000

170000

15.9

14.0

96.9

116.1

2.5 (P)

217000

209000

747000

491000

1640000

198000

12.3

9.7

74.9

80.9

5.0 (P)

217000

236000

742000

670000

1620000

177000

12.0

11.9

73.5

98.7

7.5 (P)

253000

228000

865000

860000

1480000

160000

12.8

13.8

78.3

114.5

10.0(P)

244000

231000

761000

830000

1500000

159000

11.4

13.2

69.8

109.8

P = precipitation SG = suspension growth RSG = relative suspension growth

Summary: Experiment I and II with and without metabolic activation

Treatment (mM)

RTG (%)

MF (mutants/106cells

IMF (mutants/106cells)

Precipitate

Experiment 1

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Negative control

79.6

90.7

132.8

117.1**

/

/

-

-

Negative control

110.3

188.2*

/

/

-

-

Solvent control

100.0

100.0

134.5

96.8

/

/

-

-

Solvent control

/

/

-

-

0.25

75.5

na

129.5

na

-5.0

na

-

na

0.5

na

118.2

na

125.8

na

29.0

na

-

1.0

89.4

104.4

135.6

83.7

1.1

-13.2

+

+

2.0

89.4

96.5

182.4

86.2

47.9

-10.6

+

+

4.0

85.0

83.1

118.2

121.0

-16.3

24.1

+

+

5.0

na

78.9

na

93.7

na

-3.1

na

+

7.0

97.0

72.4

155.7

103.0

21.2

6.2

+

+

8.0

108.6

77.7

154.2

110.9

19.7

14.1

+

+

9.0

85.5

na

158.2

na

23.7

na

+

Na

10.0

74.4

84.0

174.2

102.7

39.7

5.8

+

+

Positive control 1

74.2

52.1

612.2

477.4

477.7

380.6

-

-

Positive control 2

67.4

na

438.5

na

304.0

na

-

na

 

 

 

 

 

 

 

 

 

Experiment 2

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Negative control

121.7

100.5

73.0

70.2

/

/

-

-

Negative control

132.5

75.2

/

/

-

-

Solvent control

100.0

100.0

73.3

80.8

/

/

-

-

Solvent control

/

/

-

-

0.1

119.7

na

85.0

na

11.7

na

-

na

0.5

132.2

na

78.7

na

5.4

na

-

na

0.75

na

86.1

na

60.9

na

-19.9

na

-

1.0

117.1

na

84.8

na

11.5

na

+

na

1.5

na

67.0

na

91.4

na

10.6

na

-

2.0

97.9

na

72.9

na

-0.4

na

+

na

3.5

na

99.7

na

65.5

na

-15.3

na

+

4.0

134.5

na

68.3

na

-5.1

na

+

na

6.5

na

52.3

na

64.2

na

-16.6

na

+

7.0

134.0

na

64.9

na

-8.4

na

+

na

7.5

na

62.9

na

81.1

na

0.3

na

+

8.5

na

79.5

na

62.4

na

-18.4

na

+

9.0

134.8

na

79.7

na

6.3

na

+

na

9.5

na

60.6

na

56.0

na

-24.8

na

+

10.0

148.5

59.0

77.1

65.7

3.8

-15.1

+

+

Positive control 1

27.2

53.4

1873.4

544.2

1800.1

463.4

-

-

Positive control 2

129.5

na

418.3

na

344.9

na

-

na

None of the test substance mutation frequencies exceed GEF (global evaluation factor). Positive control results exceed GEF and were statistically significant: test substance results did not exceed GEF and were not statistically significant. na: these concentrations were not tested.

*Outlier, excluded from evaluation

Conclusions:
Tetra(dimethylvinylsiloxy)silane (3,3-bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane) has been tested for mutagenicity to mammalian cells in a reliable study conducted according to OECD 476 and in compliance with GLP. No evidence for a test-substance induced increase in mutant frequency was observed with or without activation when the substance was tested in mouse lymphoma L5178Y cells up to limit concentrations. Appropriate positive and solvent controls were included and gave expected results. It is concluded that the test substance is negative for mutagenicity to mammalian cells under the condition of the study.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Data are available from reliable studies for all the required in vitro endpoints. The results of all the studies are in agreement.

3,3-bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane has been tested for mutagenicity to bacteria, in a study which was conducted according to OECD Test Guideline 471 and in compliance with GLP (Dow Corning Corporation, 2011b). No evidence of a test substance related increase in the number of revertant colonies was observed with or without metabolic activation in the pre-experiment for toxicity or the initial assay using the plate incorporation method. The result was confirmed in the repeat preincubation experiment. The bacteria used were S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2. Appropriate positive, negative and solvent controls were included and gave expected results. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.

3,3-bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane has been tested in an in vitro chromosome aberration assay in peripheral human lymphocytes, conducted according to OECD Test Guideline 473 and in compliance with GLP (Dow Corning Corporation, 2011c). No evidence of a test substance related increase in chromosome aberrations was observed with or without metabolic activation in the initial or the repeat experiment. Appropriate positive and solvent controls were included and gave expected results. It is concluded that the test substance is negative for cytogenicity under the conditions of the test.

Information on the mutagenicity of 3,3-bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane to mammalian cells is available from a reliable study conducted according to OECD Test Guideline 476 and in compliance with GLP (Bioservice, 2012). No evidence for a test-substance induced increase in mutant frequency was observed with or without activation when the substance was tested in mouse lymphoma L5178Y cells up to limit concentrations. Appropriate positive and solvent controls were included and gave expected results. It is concluded that the test substance is negative for mutagenicity to mammalian cells under the condition of the study.

In vivo testing is not required as no evidence for genetic toxicity was found in the in vitro studies.


Justification for classification or non-classification

Based on the available in vitro genotoxicity data, 3,3-bis[(dimethylvinylsilyl)oxy]-1,1,5,5-tetramethyl-1,5-divinyltrisiloxane is not classified for mutagenicity according to Regulation (EC) No 1272/2008.