N,N',N''-tributyl-1-methylsilanetriamine

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:

N,N',N''-tributyl-1-methylsilanetriamine

EC Number:

240-462-2

EC Name:

N,N',N''-tributyl-1-methylsilanetriamine

Cas Number:

16411-33-9

Molecular formula:

C13H33N3Si

IUPAC Name:

N,N',N''-tributyl-1-methylsilanetriamine

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:

phenobarbital (80 mg/kg bw) and β-naphthoflavone (100 mg/kg bw) S9 mix

Test concentrations with justification for top dose:

Experiment I:
10, 31.6, 100, 316, 1000, 2500, 5000 µg/plate

Experiment II:
150, 300, 500, 900, 1500, 3000, 5000 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, TA 1537, TA 98, TA 100, TA 102, with metabolic activation

Details on test system and experimental conditions:

ACTIVATION: The protein concentration in the S9 mx 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 ortho-phosphate-buffer, pH 7.4
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 60 min
- Exposure duration: 48 hours

SELECTION AGENT (mutation assays): Vogel-Bonner Medium E agar plates

NUMBER OF REPLICATIONS: triplicate plates were used, and the experiment repeated. The initial experiment used the plate incorporation method, the repeat experiment used preincubation.

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

Evaluation criteria:

The results is considered positive when: a dose related increase in the number of revertants occurs and/or a reproducible biological 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 calculated.

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 1000 µg/plate (TA 1535 with 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 1537, TA 100, TA 102, TA 98: toxic effect at 2500 µg/plate and higher, with and without metabolic activation
- TA 1535: toxic effect at 2500 µg/plate and higher, without metabolic activation; toxic at 1000 µg/plate, with metabolic activation
Experiment II:
- TA 98, TA 100, TA 102, TA 1535: toxic effect at 1500 µg/plate, without metabolic activation and 3000 µg/plate, with metabolic activation
- TA 1537: toxic effect at 3000 µg/plate with and without metabolic activation
PRECIPITATION
No precipitation was observed in the study.

Any other information on results incl. tables

Table 1. Experiment 1, 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	11	11	14	12	110	98	31	28	177	286
Ethanol	16	13	13	15	101	102	36	37	205	266
10	21	16	14	16	126	110	38	28	203	276
31.6	16	15	14	14	130	123	36	31	215	245
100	15	15	19	12	109	131	42	40	206	261
316	14	18	15	14	105	100	31	27	194	200
1000	12	15	13	14	106	96	32	31	180	192
2500	0	9	4	2	75	0	23	0	73	89
5000	0	3	2	0	27	0	0	0	0	47
4-NOPD 10								856
2-AA 2.5	103		85		2306		1947
Sodium azide 10		1213				1131
MMS 1μL										1789

2-AA 10

742

4-NOPD 40

185

Table 2. Experiment 2, preincubation, 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	16	9	11	110	64	38	32	198	343
Ethanol	16	14	13	8	113	109	38	35	231	294
150	21	14	12	17	139	101	44	37	218	292
300	23	17	13	14	89	83	41	29	220	291
500	23	18	12	10	100	80	40	34	231	269
900	25	13	11	12	136	94	50	36	172	259
1500	21	6	13	13	114	69	36	24	188	188
3000	0	2	4	0	17	0	3	0	37	0
5000	0	0	1	0	7	0	0	0	6	0
4-NOPD 10								528
2-AA 2.5	140		105		941		592
Sodium azide 10		1402				1222
MMS 1μL										1849
4-NOPD 40				130

2-AA 10

810

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

2 -AA: 2-aminoanthracene

MMS: methylmethanesulphonate

Applicant's summary and conclusion

Conclusions:

N,N', N''-Tributyl-1-methylsilanetriamine has been tested for mutagenicity to bacteria, in a study which was conducted according to the 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 initial plate incorporation experiment or the repeat assay using the preincubation method up to limit concentrations. Appropriate positive, solvent (ethanol) and negative (untreated) 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.