Triethoxy(3-isocyanatopropyl)silane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-03-11 to 1999-08-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

guideline not mentioned.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxy(3-isocyanatopropyl)silane

EC Number:

246-467-6

EC Name:

Triethoxy(3-isocyanatopropyl)silane

Cas Number:

24801-88-5

Molecular formula:

C10H21NO4Si

IUPAC Name:

triethoxy(3-isocyanatopropyl)silane

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

Pre-experiment with and without metabolic activation:
6.7, 10, 33, 67, 100, 333, 667, 1000, 3333, 5000 µg/plate
Main experiment:
with metabolic activation:
25, 75, 200, 600, 1800, 5000 µg/plate
without metabolic activation:
7.5, 25, 75, 200, 600, 1800 µg/plate

Vehicle / solvent:

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

- Justification for choice of solvent/vehicle: Solubility properties and relative non-toxicity to bacteria

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

All salmonella strains + WP2 uvrA (with activation)

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA 98 (without activation)

Controls 3

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 100, TA 1535 (without activation)

Controls 4

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA 1537 (without activation)

Controls 5

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

WP2 uvrA

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar preincubation

DURATION

- Preincubation period: 60 minutes

- Expression time (cells in growth medium): 48 - 72 hours

NUMBER OF REPLICATIONS: 3 plates for each test concentration

DETERMINATION OF CYTOTOXICITY
- Method: Background lawn assessment, revertant colony counts

METABOLIC ACTIVATION: S9 was prepared from male Sprague Dawley rates induced with a single ip dose of Aroclor 1254, 500 mg/kg bw, 5 days before sacrifice. Each preparation of S9 was assayed for ability to metabolise 2-aminoanthracene and 7,12-dimethylbenz(a)anthracene to forms mutagenic to TA 100. S9 mix contained 10% S9, 5mM glucose-6-phosphate, 4 mM NADP, 8 mM MgCl2, 33 mM KCl. 0.5 ml was added to 100 microlitre vehicle or test article and (after pre-incubation) 2.0 ml top agar. The final concentration of S9 was therefore approximately 2%.

Evaluation criteria:

Cytotoxicity is defined as a reduction in the number of colonies by >50% compared with the solvent control and/or at least a moderate reduction in
the background lawn (background code 3,4 or 5).

The mean of each positive control must exhibit at least a three-fold increase in the number of revertants over the mean value of the respective vehicle control.

A minimum of three non-toxic dose levels are required to evaluate assay data.

A dose level is considered toxic if one or both of the following are met: (1) A >50 % reduction in the mean number of revertants per plate as
compared to the mean vehicle control. This reduction must be accompanied by an abrupt dose-dependant drop in the revertant count. (2) A reduction in the background lawn.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

600 - 1800 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

1800 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

600 - 1800 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

1800 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

600 - 1800 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 6

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

1800 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 7

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

600 - 1800 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 8

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

600 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 9

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

1800 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 10

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

600 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

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

Any other information on results incl. tables

Table 2: Dose range-finding study Number of revertants per plate (2 plates per strain)

	TA 100			WP2 uvrA
Concentration (μg/Plate)	Plate 1 + MA	Plate 2 - MA	Cytotoxic (Yes/No)	Plate 1 + MA	Plate 2 - MA	Cytotoxic (Yes/No)
0	133	98	No	16	23	No
6.7	128	110	No	13	8	No
10	123	95	No	28	17	No
33	134	98	No	13	9	No
67	150	84	No	19	19	No
100	147	111	No	17	15	No
333	146	107	No	11	20	No
667	134	104	No	22	26	No
1000	148	123	No	32	16	No
3333	146	116	No	15	18	No
5000	168	113	No	24	16	No

*solvent control with DMSO

Table 3: Experiment 1 Mutagenicity 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)
0*	16	27	No	134	161	No	11	12	No
100	21	30	No	131	156	No	11	11	No
333	11	24	No	134	163	No	10	14	No
1000	20	24	No	129	164	No	12	13	No
3333	20	32	No	141	167	No	9	11	No
5000	15	28	No	126	172	No	10	15	No
Positive control	367	873	No	720	1035	No	637	129	No

*solvent control with DMSO

Table 3: Experiment 1 Mutagenicity Assay Number of revertants per plate (mean of 3 plates)

	TA1537			WP2uvrA
Conc. (µg/plate)	— MA	+  MA	Cytotoxic (yes/no)	— MA	+  MA	Cytotoxic (yes/no)
0*	5	12	No	17	19	No
100	4	8	No	14	18	No
333	6	8	No	17	13	No
1000	4	9	No	10	16	No
3333	6	8	Yes	16	15	No
5000	6	6	Yes	17	14	No
Positive control	1070	119	No	292	108	No

*solvent control with DMSO

Table 4: Experiment 2 Mutagenicity 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)
0*	26	44	No	106	129	No	10	12	No
33	26	39	No	121	131	No	11	11	No
100	24	46	No	136	153	No	9	16	No
333	26	35	No	117	142	No	11	14	No
1000	25	39	No	119	166	No	11	11	No
5000	19	38	No	138	167	No	11	10	No
Positive control	292	901	No	534	945	No	446	106	No

*solvent control with DMSO

Table 4: Experiment 2 Mutagenicity Assay Number of revertants per plate (mean of 3 plates)

	TA1537			WP2 uvrA
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	6	5	No	21	14	No
33	5	6	No	16	14	No
100	5	7	No	21	15	No
333	4	6	No	18	15	No
1000	5	9	No	19	18	No
5000	3	7	Yes	22	15	No
Positive control	598	97	No	430	118	No

*solvent control with DMSO

Applicant's summary and conclusion

Conclusions:

Triethoxy(3-isocyanatopropyl)silane has been tested according to a protocol that is similar to OECD 471 and in compliance with GLP in Salmonella typhimurium strains TA 98, TA 100, TA 1535 and TA 1537 and E. coli WP2 uvrA. No test substance induced increase in the number of revertants was observed in the presence or absence of metabolic activation when tested up to cytotoxic concentrations. Appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.