[3-(trimethoxysilyl)propyl]urea

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:

22 Feb - 04 Apr 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

2-aminoanthracene was used as the only positive control in the presence of S9-mix, at least a second positive control substance must be included for the efficacy testing of S9-mix.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

[3-(trimethoxysilyl)propyl]urea

EC Number:

245-904-8

EC Name:

[3-(trimethoxysilyl)propyl]urea

Cas Number:

23843-64-3

Molecular formula:

C7H18N2O4Si

IUPAC Name:

[3-(trimethoxysilyl)propyl]urea

Method

Target gene:

his operon (for S. typhimurium strains) and trp operon (for E. coli strain)

Species / strain

Species / strain 1

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

Preliminary toxicity test:
- 6.7, 10, 33, 67, 100, 333, 667, 1000, 333 and 5000 µg/plate (with and without metabolic activation, TA 100 and E. coli WP2 uvrA)
Experiment I+II:
- 100, 333, 1000, 3333 and 5000 µg/plate (with and without metabolic activation)
Experiment III:
- 100, 333, 1000, 3333 and 5000 µg/plate (TA 100 without metabolic activation)
5000 µg/plate is the highest recommended dose level based on the current OECD guideline

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Acetone
- Justification for choice of solvent/vehicle: Solubility properties and relative non-toxicity to bacteria

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: +S9-mix: 2-aminoanthracene (2-AA); -S9-mix: 2-nitrofluorene (2-NF), sodium azide (NaN), 9-aminoacridine (9-AA), methyl methanesulfonate (MMS)

Remarks:

2-AA: 1 µg/plate (all TA strains), 10 µg/plate (E. coli WP2 uvrA), 2-NF: 1 µg/plate (TA 98), NaN: 1 µg/plate (TA 100, TA 1535), 9-AA: 75 µg/plate (TA 1537), MMS: 1000 µg/plate (E. coli Wp2 uvrA)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar ; preincubation

DURATION
- Preincubation period: 60 min
- Expression time (cells in growth medium): 48 h

NUMBER OF REPLICATIONS: 3 plates for each test concentration in two independent experiments

DETERMINATION OF CYTOTOXICITY
- Method: A dose level is considered toxic if one or both of the following criteria are met: 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-dependent drop in the revertant count and/or a reduction in the background lawn.

Evaluation criteria:

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. For the test material to be evaluated positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain with a minimum of two increasing concentrations of test material. Data sets for strains TA 1535 and TA 1537 were judged positive if the increase in mean revertants at the peak of the dose response is equal to or greater than three times the mean vehicle control value. Data sets for strains TA 98, TA 100 and E. coli WP2 uvrA were judged positive if the increase in mean revertants at the peak of the dose is equal to or greater than two times the mean vehicle control value.

Statistics:

Mean values and standard deviation were calculated.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 98 and 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:

not applicable

Positive controls validity:

valid

Test results 2

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:

not applicable

Positive controls validity:

valid

Additional information on results:

COMPARISON WITH HISTORICAL CONTROL DATA: All results of the vehicle and positive controls as well as the test groups 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	142	112	No	13	16	No
6.7	138	119	No	16	20	No
10	126	101	No	9	18	No
33	146	128	No	15	16	No
67	129	105	No	12	16	No
100	140	109	No	8	12	No
333	127	112	No	12	16	No
667	111	119	No	5	13	No
1000	125	120	No	12	12	No
3333	133	129	No	10	12	No
5000	144	121	No	13	14	No

*solvent control with Acetone

MA: metabolic activation (S9 -mix)

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*	14	24	No	125	156	No	12	9	No
100	18	23	No	125	143	No	9	15	No
333	26	30	No	133	159	No	12	11	No
1000	21	37	No	139	169	No	11	12	No
3333	23	31	No	133	162	No	9	11	No
5000	24	31	No	129	169	No	8	14	No
Positive control	523	2672	No	910	2698	No	673	285	No

*solvent control with Acetone

MA: metabolic activation (S9 -mix)

Table 4: 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*	7	9	No	14	17	No
100	8	7	No	19	15	No
333	7	10	No	18	20	No
1000	6	10	No	20	18	No
3333	6	10	No	17	19	No
5000	6	10	No	20	15	No
Positive control	736	424	No	610	204	No

*solvent control withAcetone

MA: metabolic activation (S9 -mix)

Table 5: 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*	13	15	No	116	98	No	8	10	No
100	13	15	No	114	84	No	7	9	No
333	12	16	No	116	97	No	9	8	No
1000	16	16	No	232	82	No	7	9	No
3333	17	19	No	125	95	No	5	9	No
5000	14	18	No	137	92	No	5	11	No
Positive control	248	876	No	638	891	No	227	134	No

*solvent control withAcetone

MA: metabolic activation (S9 -mix)

Table 6: 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	4	No	12	11	No
100	2	3	No	8	9	No
333	2	4	No	10	10	No
1000	4	4	No	9	13	No
3333	5	4	No	10	11	No
5000	5	5	No	11	10	No
Positive control	226	147	No	369	45	No

*solvent control withAcetone

MA: metabolic activation (S9 -mix)

Applicant's summary and conclusion

Conclusions:

Under test conditions with GLP, no mutagenic effect and no cytotoxicity was observed for the test substance tested up to limit concentration in any of the test strains without and with metabolic activation in the Ames test. The test substance is non mutagenic in the strains used.