Triacetoxyethylsilane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1978-01-18 to 1979-11-15

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline, with acceptable restrictions. It was not compliant with GLP. The restrictions are that only 100 cells were analysed per concentration. Read-across to the registered substance is considered scientifically justified.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

yes

Remarks:

only 100 cells were analysed per concentration

GLP compliance:

not specified

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxy(methyl)silane

EC Number:

217-983-9

EC Name:

Triethoxy(methyl)silane

Cas Number:

2031-67-6

IUPAC Name:

triethoxy(methyl)silane

Method

Species / strain

Species / strain / cell type:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

0.125-2.0 µl/m

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol

- Justification for choice of solvent/vehicle: It is assumed by the reviewer that the solvent was chosen for its solubility properties and relative non-toxicity to bacteria

Controls

Untreated negative controls:

yes

Remarks:

Media

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION

- Exposure duration: 4 hours

- Expression time (cells in growth medium): 24 hours

- Fixation time (start of exposure up to fixation or harvest of cells): 25 hours

SPINDLE INHIBITOR (cytogenetic assays): Colcemid

STAIN (for cytogenetic assays): 10 % Giemsa

NUMBER OF REPLICATIONS: 1

NUMBER OF CELLS EVALUATED: 100 cells per test conc.

DETERMINATION OF CYTOTOXICITY
- Method: Toxicity was measured as loss in growth potential of the cells induced by a 4-hour exposure to the test article followed by a 24-hour expression period in growth medium

Evaluation criteria:

The test substance is clastogenic if a statistically significant dose related increase in aberrations is shown.

Statistics:

A two-tailed t-test (Finney 1971) was used to determine statistical significance of results. Clearly positive results indicated by p < 0.01

Results and discussion

Test results

Species / strain:

mouse lymphoma L5178Y cells

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

Remarks on result:

other: strain/cell type: mouse lymphoma L5178Y cells

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 2: Results of chromosome analysis Experiment 1 without activation (per 100 cells scored)

		Solvent Control	Negative Control	Positive Control	0.125 μl/ml	0.25 μl/ml	0.5 μl/ml	1 μl/ml	2 μl/ml
Cytotoxicity		No	No	Yes	No	No	No	No	No
Chromatid aberrations	gaps	0	0	0	0	0	0	0	0
	breaks	0	0	4	0	0	0	0	0
	interchanges	0	0	0	0	0	0	0	0
	deletion	0	0	0	0	0	0	0	0
Chromosome aberrations	gaps	0	0	0	0	0	0	0	0
	breaks	0	0	0	0	0	0	0	0
	interchanges	0	0	0	0	2	0	0	0
	acentric fragment	4	3	18	1	11	5	2	1
	pulverised Cells	0	0	0	0	0	0	0	0
	pulverised chromosome	0	0	0	0	0	0	0	0
	triradial	0	0	11	0	1	0	0	1
	quadriradial	0	0	10	0	0	0	0	0
	ring	1	0	0	0	1	1	0	0
	fragment	2	0	5	4	2	6	1	0
	deletion	0	0	0	1	0	0	0	0
	diacentric chromosome	0	0	0	0	0	0	0	0
	minute chromosome	0	0	0	0	0	1	0	1
	complex rearrangement	0	0	0	0	0	0	0	0
Mitotic index (%)		7	7.4	4.4	6.8	7.4	6.8	5.8	5.6
Polyploidy (% mean freq.)		0	0	0	0	0	0	0	0
Endo reduplication		NR	NR	NR	NR	NR	NR	NR	NR

 Solvent control with Ethanol

NR not reported

Table 3: Results of chromosome analysis Experiment 1 with activation (per 100 cells scored)

		Solvent Control	Negative Control	Positive Control	0.125 μl/ml	0.250 μl/ml	0.5 μl/ml	1 μl/ml	2 μl/ml
Cytotoxicity		No	No	Yes	No	No	No	No	No
Chromatid aberrations	gaps	0	0	0	0	0	1	0	0
	breaks	0	0	3	0	0	0	0	0
	interchanges	0	0	0	0	0	0	0	0
	deletion	0	0	0	0	0	1	0	0
Chromosome aberrations	gaps	0	0	0	0	0	0	0	0
	breaks	0	0	0	0	0	0	0	0
	interchanges	0	0	3	0	0	0	0	0
	acentric fragment	2	4	3	6	7	5	10	4
	pulverised Cells	0	0	27	0	0	1	0	0
	pulverised chromosome	0	0	4	0	0	0	0	0
	triradial	2	0	2	0	0	2	3	1
	quadriradial	0	0	1	0	0	0	0	0
	ring	0	0	1	0	0	1	1	0
	fragment	4	0	2	4	4	9	8	3
	deletion	0	0	0	0	2	0	0	0
	diacentric chromosome	0	0	0	0	0	0	0	0
	minute chromosome	0	0	0	0	0	1	1	0
	complex rearrangement	0	0	1	0	0	0	0	0
Mitotic index (%)		6.8	6.4	0.8	7.8	6.6	10.8	8.6	5.4
Polyploidy (% mean freq.)		0	0	0	0	0	0	0	0
Endo reduplication		NR	NR	NR	NR	NR	NR	NR	NR

 Solvent control with Ethanol

NR not reported

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with and without metabolic activation

Triethoxy(methyl)silane has been tested according to a protocol that is similar to OECD 473. The test substance did not cause a statistically significant, dose related increase in chromosome aberrations. The test substance was considered non-clastogenic in mouse lymphoma L5178Y cells under the conditions of the test.