[3-(triethoxysilyl)propyl]urea

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate OECD test guideline and in compliance with GLP. Since this study is a read-across from CAS 23843-64-3, the reliability downgraded from RL1 to RL2.

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)

Version / remarks:

adopted 1983

Deviations:

no

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

IUPAC Name:

1-[3-(trimethoxysilyl)propyl]urea

Details on test material:

- Name of test material (as cited in study report): Y-11542
- Physical state: clear, viscous liquid
- Substance type: Alkoxysilane
- Storage condition of test material: room temperature; protected from exposure to light

Method

Target gene:

his operon (Salmonella strains); trp operon (E. coli)

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:

cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254

Test concentrations with justification for top dose:

Preliminary toxicity assay: 6.7, 10, 33, 67, 100, 333, 670, 1000, 3333, 5000 µg/plate with and without metabolic activation.
Main experiments: 100, 333, 1000, 3333, 5000 µg/plate with and without metabolic activation.

Vehicle / solvent:

- Vehicle/solvent used: acetone
- Justification for choice of solvent/vehicle: Based on Sponsor´s request and compatibility with target cells.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: +S9: 2-aminoanthracene (1 and 10 µg/plate) -S9: 2-nitrofluorene (1 µg/plate); sodium azide (1 µg/plate); 9-aminoacridine (75 µg/plate); methyl-methanesulfonate (1000 µg/plate)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 60±2 min
- Exposure duration: 48-72 h

NUMBER OF REPLICATIONS: Triplicates each in two independent experiments.


DETERMINATION OF CYTOTOXICITY
- Method: Inspection of the bacterial background lawn


OTHER:
- Positive controls: +S9: 2-aminoanthracene (1 µg/plate) for all Salmonella strains; 10 µg/plate for WP2 uvrA; -S9: 2-nitrofluorene (1 µg/plate) for TA 98; sodium azide (1 µg/plate) for TA 100 and TA 1535; 9-aminoacridine (75 µg/plate) for TA 1537; methyl-methanesulfonate ( 1000 µg/plate) for WP2 uvrA

Evaluation criteria:

For a positive response, the test article must induce 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 article. Data sets for strains TA1535 and TA1537 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 TA100, TA98, and WP2 uvrA were judged positive if the increase in mean revertants at the peak of the dose response is equal to or greater than two times the mean vehicle control value. All cultures must demonstrate the characteristic mean number of spontaneous revertants in the vehicle controls.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium 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

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:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: no precipitation occurred up to 5000 µg/plate

RANGE-FINDING/SCREENING STUDIES: No toxicity was observed up to a concentration of up to 5000 µg/plate

COMPARISON WITH HISTORICAL CONTROL DATA: Number of revertant colonies were comparable to historical control data.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Results from the first preincubation test.

With or without S9-Mix	Test substance concentration	Mean number of revertant colonies per plate
	(μg/plate)	(average of 3 plates ± Standard deviation)
		Base-pair substitution type			Frameshift type
		TA 100	TA1535	WP2 uvrA	TA98	TA1537
–	0	125 ± 3	12 ± 2	14 ± 4	14 ± 1	7 ± 3
–	100	125 ± 9	9 ± 1	19 ± 2	18 ± 10	8 ± 2
–	333	133 ± 13	12 ± 1	18 ± 4	26 ± 6	7 ± 2
–	1000	139 ± 13	11 ± 1	20 ± 1	21 ± 1	6 ± 2
–	3333	133 ± 8	9 ± 5	17 ± 1	23 ± 3	6 ± 3
–	5000	129 ± 4	8 ± 3	20 ± 2	24 ± 3	6 ± 2
Positive controls, –S9	Name	Sodium azide	Sodium azide	MMS	2-NF	9-AA
	Concentrations (μg/plate)	1	1	1000	1	75
	Mean No. of colonies/plate (average of 3 ± SD)	910 ± 25	673 ± 24	610 ± 69	523 ± 5	736 ± 64
+	0	156 ± 3	9 ± 2	17 ± 3	24 ± 2	17 ± 3
+	100	143 ± 12	15 ± 4	15 ± 4	23 ± 5	15 ± 4
+	333	159 ± 10	11 ± 4	20 ± 1	30 ± 6	20 ± 1
+	1000	169 ± 6	12 ± 3	18 ± 4	37 ± 2	18 ± 4
+	3333	162 ± 35	11 ± 3	19 ± 4	31 ± 2	19 ± 4
+	5000	169 ± 11	14 ± 3	15 ± 2	31 ± 1	15 ± 2
Positive controls, +S9	Name	2-AA	2-AA	2-AA	2-AA	2-AA
	Concentrations (μg/plate)	1	1	10	1	1
	Mean No. of colonies/plate (average of 3 ± SD)	2698 ± 89	285 ± 2	204 ± 14	2672 ± 27	204 ± 14

Table 2: Results from the second (all strains except TA100 without S9) and third (TA100;-S9) preincubation test.

With or without S9-Mix	Test substance concentration	Mean number of revertant colonies per plate
	(μg/plate)	(average of 3 plates ± Standard deviation)
		Base-pair substitution type			Frameshift type
		TA 100	TA1535	WP2 uvrA	TA98	TA1537
–	0	116 ± 5	8 ± 0	12 ± 3	13 ± 2	6 ± 2
–	100	114 ± 3	7 ± 2	8 ± 4	13 ± 2	2 ± 1
–	333	116 ± 16	9 ± 3	10 ± 2	12 ± 3	2 ± 2
–	1000	132 ± 4	7 ± 4	9 ± 1	16 ± 1	4 ± 2
–	3333	125 ± 10	5 ± 3	10 ± 3	17 ± 2	5 ± 1
–	5000	137 ± 17	5 ± 2	11 ± 4	14 ± 4	5 ± 2
Positive controls, –S9	Name		Sodium azide	MMS	2-NF	9-AA
	Concentrations (μg/plate)	1	1	1000	1	75
	Mean No. of colonies/plate (average of 3 ± SD)	638 ± 63	227 ± 87	369 ± 15	248 ± 18	226 ± 35
+	0	98 ± 30	10 ± 4	11 ± 2	15 ± 4	4 ± 2
+	100	84 ± 15	9 ± 2	9 ± 3	15 ± 1	3 ± 2
+	333	97 ± 6	8 ± 2	10 ± 4	16 ± 3	4 ± 1
+	1000	82 ± 5	9 ± 4	13 ± 2	16 ± 4	4 ± 3
+	3333	95 ± 21	9 ± 3	11 ± 3	19 ± 2	4 ± 2
+	5000	92 ± 15	11 ± 1	10 ± 3	18 ± 3	5 ± 2
Positive controls, +S9	Name	2-AA	2-AA	2-AA	2-AA	2-AA
	Concentrations (μg/plate)	1	1	10	1	1
	Mean No. of colonies/plate (average of 3 ± SD)	891 ± 66	134 ± 9	45 ± 5	876 ± 44	147 ± 55

2-NF = 2-nitrofluorene

MMS = methyl methanesulfonate

9AA = 9-aminoacridine

2AA = 2-aminoanthracene

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with and without metabolic activation

In a bacterial mutagenicity assay according to OECD 471 and GLP, no mutagenic effect was observed for the test substance tested up to limit concentration in any of the test strains in two independent experiments without and with metabolic activation. Appropriate solvent and positive controls were included and gave expected results. The test substance is non-mutagenic in the test strains used.