Triethoxy(3-thiocyanatopropyl)silane

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:

2000-05-09 to 2000-05-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxy(3-thiocyanatopropyl)silane

EC Number:

252-161-3

EC Name:

Triethoxy(3-thiocyanatopropyl)silane

Cas Number:

34708-08-2

Molecular formula:

C10H21NO3SSi

IUPAC Name:

[3-(cyanosulfanyl)propyl]triethoxysilane

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system: Male Wistar rats
- source of S9 : RCC (Cytotest Cell Research GmbH), Roßdorf, Germany.
- method of preparation of S9 mix: Wistar male rats received 80 mg/kg bw phenobarbital (i.p) and 80 mg/kg bw beta-naphthoflavone (oral) during 3 consecutive days and were sacrificed 24 h after the last administration. The livers were removed from the animals and homogenised. The S9 mix was prepared freshly before use: one part S9 fraction mixed with 9 parts of a cofactor solution.
- concentration or volume of S9 mix and S9 in the final culture medium: 10%
- quality controls of S9: enzymatic activity, sterility and protein content

Test concentrations with justification for top dose:

50-5000 µg/plate

Vehicle / solvent:

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

- Justification for choice of solvent/vehicle: Not reported

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA 98 (without activation)

Controls 2

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 100 (without activation)

Controls 3

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

TA 102 (without activation)

Controls 4

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 1535 (without activation)

Controls 5

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA 1537 (without activation)

Controls 6

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

WP2 uvrA (without activation)

Controls 7

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-Aminoflouorene

Remarks:

All strains (with activation)

Controls 8

Untreated negative controls:

yes

Remarks:

water

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-Aminoanthracene

Remarks:

All strains (with activation)

Details on test system and experimental conditions:

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

ACTIVATION:

DURATION

- Preincubation period: 30 minutes

- Expression time (cells in growth medium): 72 hours

NUMBER OF REPLICATIONS: 3 plates for each test concentration

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth; background lawn assessment

Evaluation criteria:

For a test compound or a test substance to be considered positive, it must (in two independent experiments) cause at least a doubling in the mean revertants per plate of at least one tester strain. The increase must be accompanied by a dose response towards increasing concentrations of the test article. Single increases in revertant frequencies which are not dose-related and not reproducible in two independent tests are considered non-relevant. However, when increases occur in both tests, this will be taken as an indication of a mutagenic effect.

A reduction in the number of spontaneous revertants, and / or a thinning of the background lawn is indicative of toxicity.

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:

valid

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:

valid

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:

valid

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:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium 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

Test results 6

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:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS

- Precipitation: precipitation noted at 1600 and 5000 µg/plate

COMPARISON WITH HISTORICAL CONTROL DATA: Results were within range of historical control data

Any other information on results incl. tables

Table 2: Experiment 1 Plate incorporation Number of revertants per plate

	TA 98			TA 100			TA 102
Conc. (µl/ml)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
Negative Control	13	13	No	129	237	No	380	434	No
0*	15	9	No	104	2219	No	329	351	No
50	18	2	No	103	237	No	398	312	No
160	16	7	No	111	233	No	388	308	No
500	16	5	No	130	225	No	350	347	No
1600	22	7	No	135	223	No	345	298	No
5000	13	7	No	138	199	No	349	268	No
Positive control	100	2216	No	587	1637	No	1205	837	No
Positive control 2	-	1606	No	-	1524	No	-	522	No

*solvent control with DMSO

Table 2: Experiment 1 Plate incorporation Number of revertants per plate

	TA 1535			TA 1537			WP2 uvrA
Conc. (µl/ml)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
Negative Control	12	15	No	13	16	No	12	12	No
0*	14	8	No	12	15	No	9	11	No
50	13	7	No	14	17	No	11	15	No
160	11	7	No	9	12	No	9	14	No
500	13	9	No	11	16	No	8	12	No
1600	13	10	No	17	11	No	11	14	No
5000	10	10	No	11	9	No	9	12	No
Positive control	576	31	No	43	69	No	185	40	No
Positive control 2	-	142	No	-	116	No	-	20	No

*solvent control with DMSO

Table 3: Experiment 2 Pre incubation Number of revertants per plate

	TA 98			TA 100			TA 102
Conc. (µl/ml)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
Negative Control	26	30	No	196	197	No	406	365	No
0*	23	33	No	181	182	No	350	361	No
50	31	34	No	182	185	No	391	360	No
160	30	31	No	195	179	No	361	336	No
500	37	31	No	196	174	No	374	359	No
1600	27	35	No	200	175	No	399	334	No
5000	27	28	No	191	200	No	385	277	No
Positive control	137	1966	No	680	1331	No	1390	1173	No
Positive control 2	-	1113	No	-	1064	No	-	471	No

*solvent control with DMSO

Table 3: Experiment 2 Pre incubation Number of revertants per plate

	TA 1535			TA 1537			WP2 uvrA
Conc. (µl/ml)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
Negative Control	15	11	No	6	10	No	13	11	No
0*	16	9	No	9	9	No	10	13	No
50	13	10	No	8	7	No	13	17	No
160	16	11	No	9	15	No	12	18	No
500	11	10	No	6	10	No	14	16	No
1600	12	11	No	11	13	No	8	16	No
5000	12	12	No	9	14	No	12	12	No
Positive control	555	24	No	39	78	No	222	52	No
Positive control 2	-	128	No	-	71	No	-	22	No

*solvent control with DMSO

Applicant's summary and conclusion

Conclusions:

Triethoxy(3-thiocyanatopropyl)silane has been tested for bacterial mutagenicity in an in vitro study conducted in accordance with OECD Test Guideline 471 (1997) and in compliance with GLP using Salmonella typhimurium strains TA 98, 100, 1535, 1537 and 1538, and E.coli WP2uvrA (reliability score 1). No evidence of test substance induced increase in the number of revertants was observed up to limit concentrations in any of the bacteria tested without and with metabolic activation in either the initial plate incorporation assay or the repeat experiment using the preincubation method. Appropriate untreated, solvent and positive controls were included and gave expected results. In conclusion, the test substance is non-mutagenic to bacteria under the conditions of the test.