1,1-dimethyl-N,N'-bis(1-methylpropyl)silanediamine

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,1-dimethyl-N,N'-bis(1-methylpropyl)silanediamine

EC Number:

298-130-8

EC Name:

1,1-dimethyl-N,N'-bis(1-methylpropyl)silanediamine

Cas Number:

93777-98-1

Molecular formula:

C10H26N2Si

IUPAC Name:

N,N'-Di-sec-butyl-1,1-dimethylsilanediamine

Test material form:

other: liquid

Method

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:

S9 microsomal fraction of Phenobarbital and β-Naphthoflavone induced rat livers

Test concentrations with justification for top dose:

Experiment I, with and without metabolic activation:
- TA 98, TA 100: 31.6, 100, 316, 1000, 2500, 5000 µg/plate
- TA 1535, TA 1537, TA 102: 10, 31.6, 100, 316, 1000, 2500 µg/plate
Experiment II, with and without metabolic activation: 62.5, 125, 250, 500, 1000, 3000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: the solvent was compatible with the survival of the bacteria and S9 activity

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 1535, TA 100, without metabolic activation

Controls 2

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine

Remarks:

TA 1537, TA 98, without metabolic activation

Controls 3

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

TA 102, without metabolic activation

Controls 4

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

TA 1535, TA1537, TA 98, TA 100, TA 102, with metabolic activation

Details on test system and experimental conditions:

ACTIVATION: The protein concentration in the S9 preparation was 36 mg/ml. The S9 mix contained the following co-factors: 8 mM MgCl2, 33 mM KCl, 5 mM glucose-6-phosphate, 5 mM NADP in 100 mM sodium-orthophosphate-buffer, pH 7.4, and 8.5 parts of cofactor solution were added to 1.5 parts of S9. 0.5 ml S9 mix was added to 0.1 ml test solution and 2 ml of overlay agar, giving a final concentration of approximately 3% S9 in the plates.

METHOD OF APPLICATION: in agar: plate incorporation

DURATION
- Exposure duration: 48 hours
- Expression time (cells in growth medium): 48 hours

SELECTION AGENT (mutation assays): histidine deficient agar

NUMBER OF REPLICATIONS: triplicate plates were used, and an independent repeat experiment was conducted.

DETERMINATION OF CYTOTOXICITY
- Method: condition of bacterial lawn/reduction in number of revertants

Evaluation criteria:

A test item is considered mutagenic when: a dose related increase in the number of revertants occurs; a reproducible biologically relevant positive response for at least one of the dose groups occurs in at least one strain with or without metabolic activation.

Statistics:

Relative statistics (standard deviation, mean) were calculates.

Results and discussion

Test results

Key result

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:

cytotoxicity

Remarks:

from 316 µg/plate, TA 102 without metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY:
Experiment I:
- TA 1535, TA 1537, TA 100, TA 98: 2500 µg/plate and higher, with and without metabolic activation
- TA 102: at 316 µg/plate and higher, without metabolic activation; at 2500 µg/plate, with metabolic activation
Experiment II:
- TA 1535, TA 1537, TA 100, TA 98: at 3000 µg/plate, with and without metabolic activation
- TA 102: at 1000 and higher µg/plate, without metabolic activation; at 3000 µg/plate, with metabolic activation

PRECIPITATION
No precipitation of test item was observed.

Any other information on results incl. tables

Table 1. Experiment I, plate incorporation, revertant colonies per plate (mean of three plates), with and without metabolic activation

Concentration μg/plate	TA 1535		TA 1537		TA 100		TA 98		TA 102
	+MA	-MA	+MA	-MA	+MA	-MA	+MA	-MA	+MA	-MA
A dest	15	18	24	16	139	100	25	27	237	293
Ethanol	16	20	24	15	120	122	37	30	237	237
31.6	19	19	28	18	139	97	31	41	219	212
100	22	14	21	19	140	111	22	37	175	251
316	27	16	21	17	116	105	27	41	165	249
1000	25	19	16	16	81	106	28	33	260	225
2500	16	15	21	13	59	72	14	25	235	234
5000	6	7	3	3	0	0	0	0	118	219
4-NOPD 10								798
4-NOPD 40				199
2-AA 2.5	190		147		1296		1269
2-AA 10									558
Sodium azide 10		1163				1121
MMS 1μL										2136

Table 2. Experiment II, plate incorporation, revertant colonies per plate (mean of three plates), with and without metabolic activation

Concentration µg/plate	TA 1535		TA 1537		TA 100		TA 98		TA 102
	+MA	-MA	+MA	-MA	+MA	-MA	+MA	-MA	+MA	-MA
A dest	14	14	18	14	118	109	37	19	214	311
Ethanol	20	18	15	11	117	119	45	28	216	273
62.5	18	14	22	12	119	95	41	29	212	254
125	15	12	17	14	123	109	41	33	207	284
250	17	13	23	14	114	118	34	25	214	291
500	17	19	17	13	122	116	33	29	187	268
1000	19	16	18	10	107	97	40	27	202	189
3000	2	9	7	0	71	40	22	16	98	190
4-NOPD 10								1339
4-NOPD 40				228
2-AA 2.5	233		239		2227		1756
2-AA 10									521
Sodium azide 10		1324				1348
MMS 1μL										1819

 

4 -NOPD: 4-nitro-o-phenylene-diamine

2 -AA: 2-aminoanthracene

MMS: methylmethanesulphonate

 

 

 

Applicant's summary and conclusion

Conclusions:

1,1-Dimethyl-N,N'-bis(1-methylpropyl)silanediamine has been tested for mutagenicity to bacteria, in a study which was conducted according to the OECD TG 471, in compliance 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 initial or the repeat experiments using the plate incorporation method up to limit concentrations. Appropriate positive, solvent and negative 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.