Triethoxyoctylsilane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997.11.14-1997.12.09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD draft guidelines 471 and 472 (1995)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxyoctylsilane

EC Number:

220-941-2

EC Name:

Triethoxyoctylsilane

Cas Number:

2943-75-1

Molecular formula:

C14H32O3Si

IUPAC Name:

triethoxy(octyl)silane

Test material form:

liquid

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver S9

Test concentrations with justification for top dose:

75, 200, 600, 1800 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: based on sponsor's request and compatibility with the target cells

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene 1.0 µg/plate

Remarks:

TA98, TA100, TA1535, TA1537, WP2 uvrA with metabolic activation

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA98 without metabolic activation 1.0 µg/plate

Controls 3

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA100 and TA1535 without metabolic activation 1.0 µg/plate

Controls 4

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA1537 without metabolic activation 75 µg/plate

Controls 5

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

WP2 uvrA without metabolic activation 1000 µg/plate

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

ACTIVATION: S9 mix contained glucose-6-phosphate and NADP as co-factors. 0.5 ml of S9 mix containing 10% S9 was added to agar, bacterial suspension and test substance to a total volume of 2.65, giving a final concentration of approximately 1% S9.

DURATION
- Preincubation period: 60 minutes
- Exposure duration: 48 - 72 hours

NUMBER OF REPLICATIONS: triplicate plates, experiment repeated



DETERMINATION OF CYTOTOXICITY
- Method: condition of background lawn

Evaluation criteria:

A result is positive if it causes a dose related increase in the mean revertants per plate of at least one tester strain with a minimum of two increasing concentrations of test article. This would be an increase of at least 3-fold of the solvent control for TA1535 and TA1537 and a 2-fold increase of the solvent control for TA98, TA100 and WP2 uvrA

Statistics:

None available

Results and discussion

Test results

Test results 1

Key result

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

Test results 2

Key result

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

Test results 3

Key result

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

Test results 4

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

Test results 5

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 valid

Positive controls validity:

valid

Any other information on results incl. tables

Table 1 Experiment 1 Revertants per plate - preincubation (mean of 3 plates)

Treatment µg/plate	TA98	TA 98	TA100	TA 100	TA1535	TA 1535	TA1537	TA 1537	WP2 uvrA	WP2 uvrA
	-S9	+S9	-S9	= S9	-S9	+S9	-S9	+S9	-S9	+ S9
Solvent control	19	37	138	151	8	9	6	5	16	17
75	20	30	139	148	11	14	6	7	21	24
200	23	38	123	165	10	13	6	5	18	18
600	21	37	111	160	10	12	7	8	17	18
1800	25	31	132	143	9	10	4	6	18	17
5000	20	26	125	133	11	12	5	6	13	14
Positive control	1037	916	605	790	551	112	775	87	437	511

 

Table 2 Experiment 2 Revertants per plate - preincubation (mean of 3 plates)

Treatment µg/plate	TA98	TA 98	TA100	TA 100	TA1535	TA 1535	TA1537	TA 1537	WP2 uvrA	WP2 uvrA
	-S9	+S9	-S9	+ S9	-S9	+S9	-S9	+S9	-S9	+ S9
Solvent Control	14	25	119	129	8	13	8	8	18	22
75	15	23	117	134	5	12	6	5	18	22
200	12	18	111	109	7	9	4	6	14	17
600	10	23	112	123	9	9	5	9	12	14
1800	12	23	90	119	7	8	6	8	15	14
5000	12	24	94	119	9	9	3	6	14	10
Positive control	736	975	500	921	457	94	719	87	438	358

Applicant's summary and conclusion

Conclusions:

Triethoxy(octyl)silane has been tested for mutagenicity to bacteria in a study conducted according to OECD draft guidelines 471 and in compliance with GLP. No evidence of a substance related increase in the number of revertants was observed with or without activation in Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 uvr A in the initial or the repeat experiment, both of which used the preincubation method. Appropriate solvent and positive 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.