Dimethoxymethylvinylsilane

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:

19 June 2015 to 10 July 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

2008

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dimethoxymethylvinylsilane

EC Number:

240-816-6

EC Name:

Dimethoxymethylvinylsilane

Cas Number:

16753-62-1

Molecular formula:

C5H12O2Si

IUPAC Name:

ethenyldimethoxymethylsilane

Test material form:

other: liquid

Method

Target gene:

histidine operon

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

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:

pre-experiment: 0.00316, 0.0100, 0.0316, 0.100, 0.316, 1.0, 2.5 and 5.0 μl/plate
main experiment: 0.0316, 0.100, 0.316, 1.0, 2.5 and 5.0 μl/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: an aqueous solvent was inappropriate because of the hydrolytic instability of the substance. The solvent was compatible with the survival of the bacteria and the S9 activity.

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

distilled water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

-MA; TA 100, TA 1535; 10 μg/plate

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine

Remarks:

-MA; TA 98 (10 μg/plate), TA 1537 (40 μg/plate)

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

-MA; TA 102; 1 μl/plate

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

+MA; 2.5 μg/plate; 10 μg/plate for TA 102

Details on test system and experimental conditions:

ACTIVATION:
Protein concentration in the S9 preparation: 34.0 mg/ml. S9 mix contained 5% S9 and 8 mM MgCl2; 33 mM KCl; 5 mM glucose-6-phosphate; 4 mM NADP. 0.5 ml S9 mix were added to a total volume of 2.7 ml, giving a final concentration of approximately 1% S9.

METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 60 min at 37°C
- Exposure duration: 37°C for at least 48 h in the dark

SELECTION AGENT (mutation assays): histidine deficient agar

NUMBER OF REPLICATIONS: two independent experiments, triplicate plates


DETERMINATION OF CYTOTOXICITY
- Method: other: condition of background lawn or reduction in the number of revertants down to a mutation factor of approximately ≤ 0.5

Evaluation criteria:

A test item is considered as mutagenic if:
- a clear and dose-related increase in the number of revertants occurs and/or
- a biologically relevant positive response for at least one of the dose groups occurs in at least one tester strain with or without metabolic activation.
A biologically relevant increase is:
- if in tester strains TA 98, TA 100 and TA 102 the number of reversions is at least twice as high
- if in tester strains TA 1535 and TA 1537 the number of reversions is at least three times higher
than the reversion rate of the solvent control.

Statistics:

A statistical evaluation is not regarded as necessary.

Results and discussion

Test results

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

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: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Pre-experiment - mutant frequency

Dose (µl/plate)	TA 98		TA 100
	- MA	+ MA	- MA	+ MA
Solvent control	1.0	1.0	1.0	1.0
0.00316	1.0	1.4	1.1	0.9
0.0100	1.1	1.1	1.0	1.0
0.0316	1.2	1.3	0.8	1.0
0.100	1.3	1.0	1.0	1.0
0.316	1.0	1.1	0.9	1.0
1.0	0.9	0.8	0.9	1.1
2.5	1.1	1.4	0.9	0.9
5.0	1.0	1.0	0.7	1.0
Positive control	11.2	77.7	5.5	17.7

Table 2: Plate incorporation test - number of revertants (mean of 3 plates)

Dose (µl/plate)	TA 98		TA 100		TA 1535		TA 1537		TA 102
	- MA	+ MA	- MA	+ MA	- MA	+ MA	- MA	+ MA	- MA	+ MA
Negative control	29	33	97	100	10	7	13	12	303	271
Solvent control	23	24	97	106	12	9	16	11	288	246
0.0316	28	32	81	108	11	8	8	13	296	333
0.100	31	24	94	109	11	9	11	5	295	313
0.316	24	26	83	111	9	6	12	14	259	248
1.0	20	18	89	113	10	5	14	10	229	219
2.5	25	34	91	96	5	9	12	12	226	205
5.0	23	24	72	107	8	11	7	10	258	341
Positive control	262	1891	533	1880	586	113	93	150	2202	845

Table 3: Preincubation test - number of revertants (mean of 3 plates)

Dose (µl/plate)	TA 98		TA 100		TA 1535		TA 1537		TA 102
	- MA	+ MA	- MA	+ MA	- MA	+ MA	- MA	+ MA	- MA	+ MA
Negative control	24	35	104	116	11	11	7	10	292	428
Solvent control	23	35	71	92	13	8	7	4	261	347
0.0316	28	31	75	83	12	11	4	9	308	357
0.100	22	27	74	89	13	9	7	7	285	337
0.316	17	29	74	96	11	10	4	6	236	341
1.0	28	31	78	94	11	10	9	8	260	328
2.5	27	35	76	109	12	13	5	7	268	386
5.0	27	26	65	103	10	15	4	9	292	430
Positive control	421	1362	638	1360	879	90	107	97	1732	801

Applicant's summary and conclusion

Conclusions:

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

Dimethoxy(methyl)vinylsilane has been tested for mutagenicity to bacteria, in a study which was conducted according to OECD TG 471, compliant with GLP. No evidence of a test-substance related increase in the number of revertants was observed with or without metabolic activation in Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 or TA 102 in the either the initial plate incorporation study or the independent experiment using the pre-incubation method up to limit concentrations. Appropriate positive, solvent and negative (water) controls were included and gave the expected results. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.