Triethoxyisobutylsilane

Genetic toxicity: in vitro

Administrative data

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:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate EU guideline, compliant with GLP. The range of strains does not comply with the current guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: 84/449/EEC B 14

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

The range of strains does not comply with the current guideline (No E. coli or TA 102).

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxyisobutylsilane

EC Number:

402-810-3

EC Name:

Triethoxyisobutylsilane

Cas Number:

17980-47-1

Molecular formula:

Hill formula: C10H24O3Si CAS formula: C10H24O3Si

IUPAC Name:

triethoxy(2-methylpropyl)silane

Details on test material:

- Name of test material (as cited in study report): DYNASILAN IBTEO

- Physical state: colourless liquid

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1538

Species / strain 2

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbiturate induced rat liver S9

Test concentrations with justification for top dose:

8, 40, 200, 1000, 5000 μg/plate

Vehicle / solvent:

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

Controls

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

Remarks:

acetone

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

Sodium azide (TA100 and 1535), Aminoacridine (TA1537)

Migrated to IUCLID6: (TA98 and 1538)

Details on test system and experimental conditions:

DURATION
- Preincubation period: 30 minutes at ca. 30 +/- 1C
- Exposure duration:96h

NUMBER OF REPLICATIONS: triplicate plates, experiment repeated

SELECTION AGENT (mutation assays): histidine-deficient agar

Statistics:

Relevant statistics (st.dev, mean) were calculated using software by BIOSYS.

Results and discussion

Test results

Species / strain:

other: TA 98, TA 100, TA 1537, TA 1538, TA 1535

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: Precipitation was observed at 5000 μg/plate.

ADDITIONAL INFORMATION ON CYTOTOXICITY: Cytotoxicity was not evident at any concentration.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Plate incorporation. Number of revertants per plate (mean of 3 plates).

	[TA98]			[TA100]			[TA1535]
Conc. [μg/ plate]	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
water	30	44	no	125	152	no	12	17	no
acetone	27	57	no	121	132	no	13	14	no
8	32	62	no	142	130	no	13	12	no
40	36	54	no	126	127	no	13	16	no
200	34	62	no	118	140	no	11	16	no
1000	35	61	no	120	148	no	10	13	no
5000	26	63	no	116	127	no	10	13	no
Nitrofluorene 2.5 μg	110
SodiumAzide2.5 μg				563			539
Cyclophosphamide250 μg				127	258

 

 Table 2: Plate incorporation. Number of revertantsp er plate (mean of 3 plates).

	[TA1537]			[TA1538]
Conc. [μg/plate]	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
water	19	17	no	26	34	no
acetone	14	15	no	23	27	no
8	15	21	no	27	39	no
40	11	11	no	24	35	no
200	12	17	no	30	34	no
1000	11	18	no	35	40	no
5000	8	21	no	22	30	no
Aminoacridine  25 μg	84
Nitrofluorene 2.5 μg				109

Table 3: Pre-incubation repeat assay. Number of revertants per plate (mean of 3 plates).

	[TA98]			[TA100]			[TA1535]
Conc. [μg/plate]	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
water	41	35	no	132	129	no	10	11	no
acetone	43	30	no	135	139	no	10	12	no
8	45	41	no	117	133	no	13	16	no
40	47	39	no	120	125	no	12	11	no
200	43	34	no	131	145	no	9	13	no
1000	40	39	no	142	131	no	7	12	no
5000	37	36	no	125	135	no	13	12	no
Nitrofluorene 2.5 μg	99
SodiumAzide2.5 μg				499			534
Cyclophosphamide250 μg				135	366

 

 Table 4: Pre-incubation repeat assay. Number of revertants per plate (mean of 3 plates).

	[TA1537]			[TA1538]
Conc. [μg/plate]	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
water	20	12	no	27	29	no
acetone	20	14	no	24	28	no
8	25	7	no	31	31	no
40	22	7	no	27	32	no
200	18	9	no	28	32	no
1000	22	10	no	25	40	no
5000	16	10	no	31	34	no
Aminoacridine  25 μg	82
Nitrofluorene 2.5 μg				89

 

Applicant's summary and conclusion

Conclusions:

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

Triethoxyisobutylsilane has been tested for mutagenicity to bacteria, in a study which was conducted according to the appropriate EU guideline, compliant with GLP. No evidence of a test-substance related increase in the number of revertants was observed with or without activation in the initial or the repeat experiments. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.