N-[3-(trimethoxysilyl)propyl]aniline

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Mutagenicity in bacteria (OECD 471, Ames): not mutagenic
Mutagenicity in mammalian cells: data lacking
Clastogenicity in mammalian cells: data lacking
Mutagenicity/clastogenicity in vivo: data lacking

Link to relevant study records

Reference

Reference 1

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon

Species / strain / cell type:

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

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:

preincubation test: 100, 333, 1000, 3333, 5000 µg/plate (experiment B1; valid for all strains)
preincubation test: 100, 333, 1000, 3333, 5000 µg/plate (experiment B3; valid for WP2 uvrA)
preincubation test: 3.3, 10, 33, 100, 333, 1000, 5000 µg/plate (experiment B4; valid for all Salmonella strains)

Vehicle / solvent:

Acetone

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

methylmethanesulfonate

other: 2-aminoanthracene

Remarks:

+S9: 2-AA (all salmonella strains + WP2uvrA; 1 + 10 µg/plate); sterigmatocystin (WP2; 100 µg/plate); -S9: 2-NF (TA 98; 1 µg/plate); SA (TA 100, TA 1535; 1 µg/plate); 9-AA (TA 1537; 75 µg/plate); MMS (both E. coli strains; 1000 µg/plate)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

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

NUMBER OF REPLICATIONS: 2 independent experiments with 3 plates/concentration.

DETERMINATION OF CYTOTOXICITY
- Method: reduction of bacterial background lawn; mean number of revertants per plate

Evaluation criteria:

Cytotoxicity:
- reduction of colony background lawn (code 1-5)
- reduction of mean number of revertants per plate as compared to the mean vehicle control value of >50%
Mutagenicity:
Positive reaction: 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 TA98, TA100 and WP2 uvrA (pKM101) and WP2 (pKM101) 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.

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: not observed up to 5000 µg/plate

RANGE-FINDING/SCREENING STUDIES: In the preliminary test cytotoxicity was not observed up to 5000 µg/plate

With or without S9-Mix	Test substance concentration	Mean number of revertant colonies per plate in the plate incorporation test
	(µg/plate)	(average of 3 plates±standard deviation)
		Base-pair substitution type			Frameshift type
		TA 100	TA1535	WP2 uvrA	TA98	TA1537
–	Solvent control	225±6	7±3	13±2	13±3	3±1
–	100	232±9	7±3	15±1	14±2	4±1
–	333	220±18	8±3	14±1	13±3	5±3
–	1000	209±14	8±1	16±2	14±4	3±2
–	3333	215±23	6±5	11±3	11±1	4±3
–	5000	229±28	6±3	10±1	16±4	3±2
Positive controls, –S9	Name	sodium azide	sodium azide	methyl methane sulfonate	2-nitrofluorene	9-amino-acridine
	Concentrations (µg/plate)	1	1	1000	1	75
	Average of 3 plates±sd	678±17	399±38	445±215	289±54	623±36
+	Solvent control	234±2	7±3	13±2	14±3	3±1
+	100	272±10	7±3	15±1	16±3	4±1
+	333	272±9	8±3	14±1	16±5	5±3
+	1000	232±15	8±1	16±2	14±4	3±2
+	3333	212±12	6±5	11±3	24±2	4±3
+	5000	237±44	6±3	10±1	22±8	3±2
Positive controls, +S9	Name	2-aminoanthracene	2-aminoanthracene	2-aminoanthracene	2-aminoanthracene	2-aminoanthracene
	Concentrations (µg/plate)	1	1	10	1	1
	Average of 3 plates±sd	1022±56	272±18	72±13	813±79	413±101

Table 1: Test results of main test B1.

 

Table 2: Test results of the repeat experiment B3 (WP2 uvrA) and B4 (all Salmonella strains).

With or without S9-Mix	Test substance concentration	Mean number of revertant colonies per plate in the plate incorporation test
	(µg/plate)	(average of 3 plates±standard deviation)
		Base-pair substitution type			Frameshift type
		TA 100	TA1535	WP2 uvrA	TA98	TA1537
–	Solvent control	126±5	8±2	20±2	14±3	3±2
–	3.3	114±13	14±1	-	17±4	4±1
–	10	111±6	9±0	-	17±5	5±4
–	33	108±20	6±2	-	16±3	6±0
–	100	123±5	7±2	14±4	14±6	5±2
–	333	76±23	12±3	11±3	16±5	4±1
–	1000	104±13	6±3	12±4	16±7	4±2
–	3333	-	-	12±1	-	-
–	5000	594±5	7±4	13±3	17±3	4±3
Positive controls, –S9	Name	sodium azide	sodium azide	methyl methane sulfonate	2-nitrofluorene	9-amino-acridine
	Concentrations (µg/plate)	1	1	1000	1	75
	Average of 3 plates±sd	594±5	657±69	363±4	260±20	52±18
+	Solvent control	129±8	10±2	16±5	22±1	7±0
+	3.3	138±13	10±3	-	19±2	8±5
+	10	134±10	11±6	-	28±6	5±2
+	33	130±8	11±4	-	22±2	4±1
+	100	138±8	8±4	14±6	20±7	6±2
+	333	143±12	9±1	17±2	25±7	5±2
+	1000	53±19	8±2	14±0	22±7	3±3
+	3333	-	-	17±5	-	-
+	5000	131±22	8±3	14±2	24±6	7±4
Positive controls, +S9	Name	2-aminoanthracene	2-aminoanthracene	2-aminoanthracene	2-aminoanthracene	2-aminoanthracene
	Concentrations (µg/plate)	1	1	10	1	1
	Average of 3 plates±sd	858±31	94±6	106±19	731±15	97±23

 

Conclusions:

Interpretation of results:
negative

N-[3-(trimethoxysilyl)propyl]aniline has been tested for mutagenicity in bacteria, in a study which was conducted according to OECD 471 and in compliance with GLP. No evidence of a test substance related increase in the number of revertants was observed with or without metabolic activation in a preincubation experiment. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Species / strain / cell type:

E. coli WP2 uvr A pKM 101

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:

preincubation test: 10, 33, 100, 333, 1000, 5000 µg/plate (all strains except WP2 (pKM101))
preincubation test: 0.033, 0.1, 0.33, 1, 3.3, 10, 33, 100, 333, 1000, 5000 µg/plate (WP2 (pKM101))

Vehicle / solvent:

Acetone

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

methylmethanesulfonate

other: 2-aminoanthracene, sterigmatocystin

Remarks:

+S9: 2-AA (all salmonella strains + WP2uvrA; 1 + 10 µg/plate); sterigmatocystin (WP2; 100 µg/plate); -S9: 2-NF (TA 98; 1 µg/plate); SA (TA 100, TA 1535; 1 µg/plate); 9-AA (TA 1537; 75 µg/plate); MMS (both E. coli strains; 1000 µg/plate)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

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

NUMBER OF REPLICATIONS: 2 independent experiments with 3 plates/concentration.

DETERMINATION OF CYTOTOXICITY
- Method: reduction of bacterial background lawn; mean number of revertants per plate

Evaluation criteria:

Cytotoxicity:
- reduction of colony background lawn (code 1-5)
- reduction of mean number of revertants per plate as compared to the mean vehicle control value of >50%
Mutagenicity:
Positive reaction: 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 TA98, TA100 and WP2 uvrA (pKM101) and WP2 (pKM101) 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.

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 98, TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

from 1000 µg/plate in main tests

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

from 1000 µg/plate in main tests

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A pKM 101

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

5000 µg/plate in main tests

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: =10 µg/plate (first test), no precipitation in second experiment

RANGE-FINDING/SCREENING STUDIES: In the preliminary test cytotoxicity was observed from 667 µg/plate onwards.

Based on the inconsistencies regarding precipitation and toxicity a new study was conducted with a new sample of the test article.

Conclusions:

Interpretation of results:
negative

N-[3-(trimethoxysilyl)propyl]aniline has been tested for mutagenicity in bacteria, in a study which was conducted according to OECD 471 and in compliance with GLP. No evidence of a test substance related increase in the number of revertants was observed with or without metabolic activation in a preincubation experiment. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test. Based on the inconsistencies regarding precipitation and toxicity between experiment 1 and 2 a new study was conducted with a new sample of the test article.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

N-[3-(trimethoxysilyl)propyl]aniline has been tested for mutagenicity in bacteria, in a study which was conducted according to OECD 471 and in compliance with GLP (Microbial Associates, 1996a). No evidence of a test substance related increase in the number of revertants was observed with or without metabolic activation in a preincubation experiment. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test. Based on inconsistencies regarding precipitation and toxicity between experiment 1 and 2 a new study was conducted with a new sample of the test article to confirm the negative genotoxic results.

The mutagenicity of N-[3-(trimethoxysilyl)propyl]aniline in bacteria was assessed in a repeat experiment according to OECD Guideline 471 with Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100 and the Escherichia coli strain WP2 uvrA (Microbiological Associates, 1996b). The tester strains were treated using the pre incubation method both with and without S9-mix. The concentrations tested were 100 - 5000 µg/plate (Salmonella strains experiment B1, Escherichia coli strain experiments B1+B3) and 3.3 - 5000 µg/plate (Salmonella strains experiment B4). Results achieved with vehicle (Acetone) and positive controls were valid. No genotoxicity was observed in the presence and absence of metabolic activation. No precipitation was observed up to the highest dose tested. No appreciable cytotoxicity (defined as reduction of colonies by more than 50% and/or by a scarce background lawn) was observed in any strains.

In conclusion, N-[3-(trimethoxysilyl)propyl]aniline did not induce mutations in bacteria under the test conditions applied.

Justification for classification or non-classification

The available in vitro data are reliable and suitable for classification and fulfil the standard requirements given in Annex VII of Regulation (EC) 1272/2008. Based on the available data, there is no indication that the substance induces genetic toxicity. Nevertheless, no final decision on classification for genetic toxicity according to Regulation (EC) 1272/2008 or Directive 67/548/EEC can be made, as no information on mutagenicity and clastogenicity in mammalian cells/in vivo is available.