Triethoxy(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)silane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-08-27 to 2016-01-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

2014

Deviations:

no

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxy(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)silane

EC Number:

257-473-3

EC Name:

Triethoxy(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)silane

Cas Number:

51851-37-7

Molecular formula:

C14H19F13O3Si

IUPAC Name:

triethoxy(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)silane

Constituent 2

Reference substance name:

[2-(Perfluorohexyl)ethyl]triethoxysilane

IUPAC Name:

[2-(Perfluorohexyl)ethyl]triethoxysilane

Test material form:

other: liquid

Method

Species / strain

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Details on mammalian cell type (if applicable):

- Type and identity of media: minimum essential medium (MEM)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes

Metabolic activation:

with and without

Metabolic activation system:

phenobarbital (80 mg/kg bw) and β-naphthoflavone (100 mg/kg bw) induced rat liver S9

Test concentrations with justification for top dose:

Experiment I:
20, 50, 100 and 200 μg/mL without metabolic activation
50, 100, 200 and 500 μg/mL with metabolic activation
Experiment II:
100, 200 and 500 μg/mL without metabolic activation

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: According to the solubility test, the test item was soluble in ethanol. The solvent was compatible with the survival of the cells and the S9 activity.

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

treatment medium

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Remarks:

without metabolic activation

Controls 2

Untreated negative controls:

yes

Remarks:

treatment medium

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

ACTIVATION: S9 supernatant was mixed with S9 co-factor solution to result in a final protein concentration of 0.75 mg/mL in the cultures. The co-factors added were: 8 mM MgCl2, 33 mM KCl, 5 mM Glucose-6-phosphate, 5 mM NADP in 100 mM sodium-phosphate-buffer pH 7.5.

DURATION

- Exposure duration:
Experiment I: 4 hours, with and without metabolic activation
Experiment II: 21 hours, without metabolic activation
- Expression time (cells in growth medium): Experiment I, 16 +/- 2 hours with and without metabolic activation
- Fixation time (start of exposure up to fixation or harvest of cells): 21 hours after start of exposure

SPINDLE INHIBITOR (cytogenetic assays): Colcemid (0.2 μg/mL culture medium) was added to the cultures about 2.5 hours before preparation of the cells
STAIN (for cytogenetic assays): Giemsa

NUMBER OF REPLICATIONS: duplicate cultures

NUMBER OF CELLS EVALUATED: 300 metaphases per concentration were scored for chromosome analysis

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index and relative increase in cell count (RICC) (%)

OTHER EXAMINATIONS:
- Determination of polyploidy: yes

Evaluation criteria:

The result is considered positive when:
- at least one of the test concentrations exhibits a statistically significant increase compared to the concurrent negative control
- the increase is dose-related when evaluated with an appropriate trend test
- any of the results are outside the distribution of the historical negative control data

Statistics:

Fisher´s exact test was used to verify the results in the experiment

Results and discussion

Test results

Key result

Species / strain:

Chinese hamster lung fibroblasts (V79)

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

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation:
Experiment I: at 100 μg/mL and higher without metabolic activation, and at 200 μg/mL and higher with metabolic activation
Experiment II: at 500 μg/mL without metabolic activation

Any other information on results incl. tables

Table 1: Summary, experiment I and II, with and without metabolic activation

	Dose Group	Concentration µg/mL	Relative Mitotic Index  (%)	RICC (%)	Mean % Aberrant Cells			Historical Laboratory Negative Control Range	Precipitation
					Including Gaps		Excluding Gaps
Experiment I and II, without metabolic activation
Experiment I 4 hour treatment, 21 hour preparation interval	C	0	100	105	4.0	2.0		0.0% - 4.0 % aberrant cells	-
	S	0	100	100	3.3	1.7			-
	3	20	101	94	2.3	0.3			-
	4	50	95	105	4.3	1.3			-
	5	100	101	89	1.7	1.0			+
	6	200	99	100	2.3	1.7			+
	EMS	900	117	120	9.7	8.3			-
Experiment II 21 hour treatment, 21 hour preparation interval	C	0	99	119	1.7	0.3		0.0 % - 4.0 % aberrant cells	-
	S	0	100	100	3.3	2.0			-
	4	100	101	110	3.3	1.7			-
	5	200	105	93	2.3	1.0			-
	6	500	109	92	1.7	0.7			+
	EMS	400	78	78	12.3	9.0			-
Experiment I, with metabolic activation
Experiment I 4 hour treatment, 21 hour preparation interval	C	0	109	114	2.3	1.0		0.0 % - 4.3 % aberrant Cells	-
	S	0	100	100	1.3	0.7			-
	3	50	106	99	1.7	1.0			-
	4	100	80	77	5.7	1.7			-
	5	200	91	82	2.7	1.0			+
	6	500	74	79	1.7	1.0			+
	CPA	1.5	98	150	8.7	7.3			-

C: Negative Control (Culture Medium)

S: Solvent Control (EtOH 0.5 % v/v)

EMS: Ethylmethanesulfonate

CPA: Cyclophosphamide

+ : With precipitation

- : Without precipitation

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative with and without metabolic activation

[2-(Perfluorohexyl)ethyl]triethoxysilane has been tested for ability to cause chromosome aberrations in Chinese hamster V79 cells according to OECD TG 473 and in compliance with GLP (Eurofins BioPharma, 2016). No increase in the number of cells with aberrations was observed either with or without metabolic activation when tested up to precipitating concentrations. Appropriate solvent, negative (treatment medium) and positive controls were included and gave the expected results. It is concluded that the test substance is negative for the induction of chromosome aberrations under the conditions of this study.