N-[3-(triethoxysilyl)propyl]ethylenediamine

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Genetic toxicity in vitro:

Mutagenicity in bacteria (OECD 471, Ames): negative with and without metabolic activation in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537.

Cytogenicity in mammalian cells: testing not required as a reliable in vivo micronucleus test is available on the structural analogue substance CAS 1760-24-3.

Mutagenicity in mammalian cells (similar to OECD 476, MLA): negative with and without metabolic activation in CHO cells (RA from CAS 1760-24-3)

Link to relevant study records

Reference

Reference 1

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:

1994-10-19 to 1994-11-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate OECD test guideline, with acceptable restrictions. The restrictions were [4 strains only. Non-standard positive controls. only 2-aminoanthracene as +S9 control]

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1983

Deviations:

yes

Remarks:

4 strains only. Non-standard positive controls. only 2-aminoanthracene as +S9 control

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

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

33.3, 100, 333.3, 1000, 2500 and 5000 µg/pate with and without metabolic activation

Vehicle / solvent:

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

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

Untreated negative controls:

yes

Remarks:

Untreated culture

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 1535, TA 100 (without activation)

Untreated negative controls:

yes

Remarks:

Untreated culture

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine

Remarks:

TA 1537, TA 98 (without activation)

Untreated negative controls:

yes

Remarks:

Untreated culture

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

DURATION

- Preincubation period: 60 minutes

- Exposure duration: 48 hours



NUMBER OF REPLICATIONS: 3 plates for each test concentration

DETERMINATION OF CYTOTOXICITY
- Method: background lawn assessment

Evaluation criteria:

A test article is considered mutagenic if in the strain TA 100 the number of reversions is at least twice as high and in strains TA 1535, TA 1537 and TA 98 at least three times higher as compared to the spontanious reversion rate. A dose dependant and reproducible increase in the number of revertants is an indication of possible existing mutagenic potential regardless of highest dose value.

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:

cytotoxicity

Remarks:

- S9 (pre-incubation test): TA 98 and TA1537 at 5000 µg/plate, while TA 100 at 2500 µg/plate. + S9 (pre-incubation test): TA 1537 at 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

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

	TA 98			TA 100
Concentration (μg/Plate)	Plate 1 + MA	Plate 2 - MA	Cytotoxic (Yes/No)	Plate 1 + MA	Plate 2 - MA	Cytotoxic (Yes/No)
Negative control	15	17	No	163	122	No
0	24	16	No	147	129	No
3.3	12	17	No	150	128	No
10	22	20	No	154	116	No
33.3	18	12	No	158	120	No
100	19	19	No	155	119	No
333.3	21	14	No	87	107	No
1000	23	16	No	159	109	No
2500	20	13	No	128	111	No
5000	57	10	No	126	111	No
Positive control	555	142	No	973	353	No

*solvent control with ethanol

 

Table 3: Experiment 1 Mutagenicity Assay (plate incorporation) 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)
Negative control	17	15	No	122	163	No	13	13	No
0	16	24	No	129	147	No	14	19	No
33.3	12	18	No	120	158	No	15	16	No
100	19	19	No	119	155	No	15	16	No
333.3	14	21	No	107	87	No	13	15	No
1000	16	23	No	109	159	No	12	20	No
2500	13	20	No	111	128	No	11	19	No
5000	10	57	No	111	126	No	12	16	No
Positive control	142	555	No	353	973	No	69	405	No

*solvent control with ethanol

 

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

	TA1537
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)
Negative control	25	29	No
0	19	24	No
33.3	17	21	No
100	18	23	No
333.3	18	21	No
1000	20	22	No
2500	16	22	No
5000	14	22	No
Positive control	79	279	No

*solvent control with ethanol

 

Table 4: Experiment 2 Mutagenicity Assay (pre-incubation) 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)
Negative control	27	39	No	130	136	No	10	13	No
0	31	38	No	103	122	No	17	19	No
33.3	27	36	No	92	129	No	12	19	No
100	28	42	No	105	126	No	11	15	No
333.3	29	32	No	94	122	No	12	19	No
1000	22	37	No	71	142	No	15	20	No
2500	18	31	No	9	91	Yes	10	13	No
5000	0	31	Yes	0	70	Yes	11	8	No
Positive control	218	287	No	808	389	No	862	122	No

*solvent control with Ethanol

 

Table 4: Experiment 2 Mutagenicity Assay (pre-incubation) number of revertants per plate (mean of 3 plates)

	TA1537
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)
Negative control	29	31	No
0	29	32	No
33.3	27	36	No
100	26	35	No
333.3	28	33	No
1000	27	35	No
2500	19	25	No
5000	8	4	Yes
Positive control	94	121	No

*solvent control with ethanol

MA: Metabolic activation

Conclusions:

negative with metabolic activation
negative without metabolic activation

Under test conditions, 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. The test substance is non-mutagenic in test strains used.

Reference 2

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988-01-13 to 1988-03-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Qualifier:

according to guideline

Guideline:

other: EPA Health Effects Test Guidelines HG-Gene Muta-Somatic Cells (1983)

Deviations:

no

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Target gene:

HGPRT (hypoxanthine-guanine phosphoribosyl transferase)

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

- Type and identity of media: Ham's Modified F12 Medium
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: no
- Periodically "cleansed" against high spontaneous background: no

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-1254 induced rat liver S9

Test concentrations with justification for top dose:

without metabolic activation: 2.5, 3.0, 3.25, 3.5 and 4.0 mg/ml, with metabolic activation: 2.0, 2.5, 3.0, 3.5, 4.0 and 4.5 mg/ml

Vehicle / solvent:

DMSO

Untreated negative controls:

yes

Remarks:

cell culture medium

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Remarks:

without metabolic activation

Untreated negative controls:

yes

Remarks:

cell culture medium

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

N-dimethylnitrosamine

Remarks:

with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 5 hours (with and without metabolic activation)
- Expression time (cells in growth medium): 9-12 days
- Selection time: 18 and 24 hours

SELECTION AGENT (mutation assays): TG selective medium

NUMBER OF REPLICATIONS: Duplicate cultures. Surviving fraction was determined at 18 and 24 hours after removal of chemical using 4 plates per culture and 100 cells per plate; mutant frequency was determined using 5 plates per culture. The test was repeated.



DETERMINATION OF CYTOTOXICITY
- Method: plating efficiency

ACTIVATION: S9 mix contained glucose-6-phosphate and NADP as co-factors, and 5% of S9. 1.0 ml of S9 mix was added to 4 ml of culture medium, giving a final concentration of 1% S9.

Evaluation criteria:

The criteria for interpretation of the test results as a positive or negative response depend upon both the level of statistical significance from the concurrent control and the evidence of a dose-response effect following treatment. When a definite dose-response relationship is not evident, but one or more marginally significant values are obtained, a careful examination of the data from the concurrent positive and negative controls and comparisons to historical control data may be used to evaluate the probable biological significance of the responses.

Statistics:

Box-Cox transformation

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

4.0 mg/ml with metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

CHO Mutation Assay: with and without metabolic activation

Results on evaluation of plating efficiency and mutant colonies - Experiment 1

	Mutant colonies		Plating efficiency
Test chemical	(Total of 2 plates)		% of Combined Solvent Controls
	- S9	+S9	-S9	+S9
Negative control	0	18	106.3	105.9
Solvent control A	20	2	93.7	102.3
Solvent control B	0	0	106.3	97.8
2.0A	-	6	-	120.5
2.0B	-	13	-	104.4
2.5A	6	35	103.4	107.5
2.5B	1	15	110.0	100.5
3.0A	5	4	104.6	91.0
3.0B	2	0	124.4	109.2
3.25A	5	-	101.1	-
3.25B	5	-	96.0	-
3.5A	0	0	89.4	116.0
3.5B	1	0	103.7	107.7
4.0A	0	-**	114.7	-**
4.0B	5	-**	94.0	-**
Positive control	143	55	115.7	113.2

**= Cytotoxic, cultures did not grow

Results on evaluation of plating efficiency and mutant colonies - Experiment 2

Test chemical	Mutant colonies (Total of 2 plates)	Plating efficiency
	+S9
Negative control	13	88.2
Solvent control A	0	104.1
Solvent control B	1	95.8
2.25A	12	118.7
2.25B	0	99.7
2.5A	0	106.8
2.5B	0	111.1
2.75A	0	101.9
2.75B	0	96.6
Positive control	63	92.6

Conclusions:

negative with and without metabolic activation

The test material has been tested in a reliable study according to an appropriate US EPA test guideline that is equivalent to OECD 476 and under GLP. An increase in mutant frequency was observed in one of two duplicate cultures with metabolic activation at one concentration in the initial experiment. No other increase in mutant frequency was observed at any concentration with and without activation (5 hours treatment). The experiment was repeated (with metabolic activation): no increase in mutant frequency was observed. The appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for the induction of mutations in CHO cells under the conditions of the test.

Reference 3

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to the Additional Information field in the endpoint study summary.

Reason / purpose for cross-reference:

read-across source

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

4.0 mg/ml with metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: BRRC, 1988

Conclusions:

negative with and without metabolic activation
The test material has been tested in a reliable study according to an appropriate US EPA test guideline that is equivalent to OECD 476 and under GLP. An increase in mutant frequency was observed in one of two duplicate cultures with metabolic activation at one concentration in the initial experiment. No other increase in mutant frequency was observed at any concentration with and without activation (5 hours treatment). The experiment was repeated (with metabolic activation): no increase in mutant frequency was observed. The appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for the induction of mutations in CHO cells under the conditions of the test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Genetic toxicity in vivo:

Micronucleus assay in mouse (EPA 560/6-83-001, similar to OECD 474): negative (RA from CAS 1760-24-3)

Link to relevant study records

Reference

Reference 1

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988-03-15 to 1988-04-08

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was conducted according to a test protocol that is similar to the appropriate OECD test guideline, and in compliance with GLP. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance (CAS 1760-24-3). Only 1000 cells/animal were scored for micronuclei.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

number of micronucleated PCEs scored per 1000 cells, not 2000

Qualifier:

according to guideline

Guideline:

other: EPA Health Effect T G, EPA Report 560/6-83-001

Deviations:

no

GLP compliance:

yes

Type of assay:

micronucleus assay

Species:

mouse

Strain:

Swiss Webster

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Portage, MI, USA
- Age at study initiation: 5 weeks
- Weight at study initiation: male - 22.5 g - 28.0 g. female - 19.8 g - 21.7 g
- Assigned to test groups randomly: randomised separately by sex
- Fasting period before study: no
- Housing: 5 mice/sex/cage in shoe-box type plastic cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): controlled but not specified
- Humidity (%): controlled but not specified
- Air changes (per hr): not known
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil
- Justification for choice of solvent/vehicle: incompatible with water thus corn oil was used
- Concentration of test material in vehicle: 200 mg/kg

Duration of treatment / exposure:

not applicable

Frequency of treatment:

One treatment only

Post exposure period:

30, 48 and 72 hours

Dose / conc.:

87.5 mg/kg bw/day (actual dose received)

Dose / conc.:

175 mg/kg bw/day (actual dose received)

Dose / conc.:

280 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

5

Control animals:

yes

Positive control(s):

Triethylenemelamine
- Justification for choice of positive control(s): known to demonstrate the sensitivity and responsiveness of the animals in the definitive test.
- Route of administration: i p
- Doses / concentrations: 0.3 mg/kg bw

Tissues and cell types examined:

Blood was collected by nicking the tail of each animal with a scalpel and slides prepared for each animal per sampling time. Polychromatic erythrocytes (PCE's) were examined.

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: Determination of the PCE/NCE ratio for the groups of animals with partial mortality was used to evaluate the possibility of bone marrow cytotoxicity from the test chemical. Three dose levels of approximately 80%, 50% and 25% of the LD50 value were evaluated for effects upon the incidence of micronuclei.


DETAILS OF SLIDE PREPARATION: Slides were stained with Gurr's R-66 Giemsa diluted in phosphate buffer. Slides were coded by animal number only and read blindly.

METHOD OF ANALYSIS: A minimum of 1000 PCE's were examined microscopically for each animal per sample time. The PCE/NCE ratio for approximately 1000 total cells was calculated and recorded. The number of micronucleated PCE/1000 NCE was recorded.

Evaluation criteria:

A test result is considered to be negative if no statistically significant or dose related increases are apparent between the vehicle control and groups of animals treated with Organofunctional Silane A-1120.

Statistics:

Fisher's Exact Test (Sokal and Rohlf, 1981)

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Remarks:

PCE/NCE ratio was reduced at highest concentration, 48 h exposure and at all doses, 72 h exposure.

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 125 mg/kg bw - 2000 mg/kg b
- Solubility: Incompatible with water thus corn oil was used
- Clinical signs of toxicity in test animals: All mice dosed at 1000 mg/kg bw and 2000 mg/kg bw died. 500 mg/kg bw was lethal to 4 out of 5 females and all the male mice. One female tested at 250 mg/kg bw died.
- Evidence of cytotoxicity in tissue analyzed: a decrease in the PCE/NCE ratio to 80% of the control value was observed at the 48 hour treatment interval. At 72 hours the PCE/NCE ratios had increased.
- Harvest times: 48 hours

RESULTS OF DEFINITIVE STUDY

- Induction of micronuclei (for Micronucleus assay): negative.
- Ratio of PCE/NCE (for Micronucleus assay): PCE/NCE ratio was slightly decreased at 72 hour treatment interval.
- Appropriateness of dose levels and route: Both dose levels and route were appropriate.
- Statistical evaluation: Analysis of variance indicated no sex-related differences in the incidence of micronuclei. No statistically significant (p ≤ 0.01) or treatment related increases in the numbers of micronuclei were observed at any dose or treatment interval.

Table 3: Summary of micronucleus results

	30 hours				48 hours				72 hours
Treatment groups mg/kg bw	Number of PCE’s with micronuclei per 1000 PCE’s		Mean PCE’s/1000 NCE (SD)		Number of PCE’s with micronuclei per 1000 PCE’s		Mean PCE’s/1000 NCE (SD)		Number of PCE’s with micronuclei per 1000 PCE’s		Mean PCE’s/1000 NCE (SD)
	Male	Female	Group mean	SD	Male	Female	Group mean	SD	Male	Female	Group mean	SD
Vehicle control	4.0 (2.00)	1.6 (0.89)	33.7	5.52	2.4 (2.70)	3.6 (1.14)	36.4	4.24	3.8 (2.05)	3.8 (2.68)	42.9	3.25
87.5	5.0 (2.55)	3.6 (1.52)	31.8	6.79	3.0 (1.73)	2.2 (0.84)	36.0	0.28	6.4 (2.19)	2.8 (1.64)	33.9	2.12
175	2.6 (1.52)	4.0 (1.22)	34.9	8.06	3.2 (1.10)	3.8 (1.64)	37.2	7.92	2.3 (0.96)	5.2 (3.96)	35.5	6.68
280	3.4 (2.19)	3.6 (2.19)	35.4	4.81	3.4 (3.29)	3.0 (1.22)	30.4	3.39	3.8 (1.92)	1.2 (0.84)	27.9	1.27
Positive control	36.2 (16.84)	28.6 (10.31)	27.4	9.05	Not evaluated		Not evaluated		Not evaluated		Not evaluated

Table 4 Summary of micronucleus frequency and statistical differences from controls (Fisher's exact test, one-tailed)

Treatment/dose mg/kg bw	No. PCE observed	PCE with micronuclei	Statistical significance
	30 hour sample
Vehicle control	10 000	28	NS
87.5	10 000	43	0.05>p>0.01*
175	10 000	33	NS
280	10 000	35	NS
Positive control	10 000	324	p<0.001
	48 hour sample
Vehicle control	10 000	30	NS
87.5	10 000	26	NS
175	10 000	35	NS
280	10 000	32	NS
	72 hour sample
Vehicle control	10 000	38	NS
87.5	10 000	46	NS
175	10 000	35	NS
280	10 000	25	NS

Results from sexes are combined as no sex-related differences were shown.

* not considered of biological significance

Conclusions:

negative
The test material has been tested in a reliable study according to EPA Health Effect T G, Report 560/6-83-001, which is similar to OECD 474, and under GLP conditions. No treatment related increases in numbers of micronuclei in PCE's of Swiss-Webster mice were observed at concentrations of 87.5, 175 and 280 mg/kg bw. Relatively high dose levels of the test compound were tested up to 80% of the LD50 with no indication of significant induction of micronuclei. The PCE/NCE ratio was reduced at the highest concentration, 48 h exposure and at all doses, 72 h exposure, indicating exposure of the target tissue to the test substance. The test compound is considered to be negative for the induction of micronuclei under the conditions of this test.

Reference 2

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

chromosome aberration

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to the Additional Information field in the endpoint study summary.

Reason / purpose for cross-reference:

read-across source

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Remarks:

PCE/NCE ratio was reduced at highest concentration, 48 h exposure and at all doses, 72 h exposure.

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

other: BRRC, 1988

Conclusions:

negative
The test material has been tested in a reliable study according to EPA Health Effect T G, Report 560 /6-83-001, which is similar to OECD 474, and under GLP conditions. No treatment related increases in numbers of micronuclei in PCE's of Swiss-Webster mice were observed at concentrations of 87.5, 175 and 280 mg/kg bw. Relatively high dose levels of the test compound were tested up to 80% of the LD50 with no indication of significant induction of micronuclei. The PCE/NCE ratio was reduced at the highest concentration, 48 h exposure and at all doses, 72 h exposure, indicating exposure of the target tissue to the test substance. The test compound is considered to be negative for the induction of micronuclei under the conditions of this test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Genetic toxicity (mutagenicity) in bacteria in vitro

The mutagenicity potential of N-[3-(triethoxysilyl)propyl]ethylenediamine in bacteria was assessed in an experiment according to OECD 471 with Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100 (RCC, 1995). A deviation to the guideline was the use of 2-aminoanthracene as the sole positive control substance in the presence of S9-mix and only 4 strains of Salmonella typhimurium were used. No further information is given, if the S9-mix has been characterised with a second substance. This deviation was supposed to have no implication on the outcome of the study results. The tester strains were treated using both the pre-incubation and the plate incorporation methods, with and without S9-mix, respectively. The concentrations tested were 33.3 - 5000 µg/plate in the presence and absence of S9-mix. Results achieved with vehicle (ethanol) and positive controls were valid. No genotoxicity was observed in the presence and absence of metabolic activation. Growth inhibition was observed in some of the test groups with and without metabolic activation at 2500 and 5000 µg/plate in the pre-incubation test. In conclusion, N-[3-(triethoxysilyl)propyl]ethylenediamine did not induce mutations in bacteria under the test conditions applied.

 

No data are available for mutagenicity to a bacterial strain capable of detecting cross-linking or oxidising mutagens. In view of the lack of genetic toxicity demonstrated in studies on mammalian cells, and the absence of structural features that indicate that such mutagenicity is likely, testing in an appropriate 5thstrain is not considered necessary. In addition, the only silicon-containing substance which has given a positive result in a bacterial strain capable of detecting cross-linking or oxidising mutagens contains an epoxy side-chain (which is associated with cross-linking mutagenicity), and this substance was positive in Salmonella typhimurium strains TA 100, TA 1535 as well as in E.coliWP2uvrA.

 

No measured data are available to assess the mutagenicity or cytogenicity potential of N-[3-(triethoxysilyl)propyl]ethylenediaminein mammalian cells, however, reliable data are available for the structural analogue substance, N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3).

 

READ-ACROSS JUSTIFICATION

To reduce animal testing REACH recommends to make use of a read-across approach where appropriate based on the high accordance in properties relevant for the specific endpoint.  In the case of genetic toxicity relevant properties are structural similarity as well as physical-chemical and basic toxicological parameters in the same range. Especially functional groups that are associated with genetic toxicity have to be compared. In the following paragraphs the read-across approach for N-[3-(triethoxysilyl)propyl]ethylenediamine (CAS 5089-72-5) is evaluated point by point.

 

Read-across hypothesis

For N-[3-(triethoxysilyl)propyl]ethylenediamine an Ames test is available, which was negative in the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100 when tested up to the limit dose of 5000 µg/plate. No measured data are available to assess the mutagenicity or cytogenicity potential of N-[3-(triethoxysilyl)propyl]ethylenediamine in mammalian cells, however, reliable data are available for the structural analogue substance, N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3). None of these tests showed a positive result, indicating no genotoxic properties of the test substance. This is further supported by the fact that no positive results were observed with other substances in the amino functional alkoxysilanes analogue group (PFA, 2013t). The substances have the same or similar hydrolysis products and therefore read-across to the analogue is appropriate. The other hydrolysis product methanol is not genotoxic. Additional information is given in a supporting report attached in Section 13 of the IUCLID 5 dossier.

 

Discussion

Genetic toxicity (mutagenicity) in mammalian cells in vitro

N-(3-trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) has been tested in a reliable study according to an appropriate US EPA test guideline that is equivalent to OECD 476 and under GLP (BRRC, 1988a). An increase in mutant frequency was observed in one of two duplicate cultures with metabolic activation at one concentration in the initial experiment. No other increase in mutant frequency was observed at any concentration (0.1 to 4.0 mg/ml) with and without activation (5 hours treatment). The experiment was repeated (with metabolic activation): no increase in mutant frequency was observed. Cytotoxicity was observed in all test strains at the top concentration of 4.0 mg/ml with metabolic activation. The appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is negative for the induction of mutations in CHO cells under the conditions of the test.

 

Genetic toxicity (cytogenicity) in mammalian cells in vitro

No in vitro cytogenicity study is available; testing is not required as a reliable in vivo micronucleus assay is available for the structural analogue substance, N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3).

 

Genetic toxicity (mutagenicity) in mammalian cells in vivo

N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) has been tested in a reliable in vivo micronucleus study according to EPA Health Effect T G, Report 560/6-83-001, which is similar to OECD 474, and under GLP conditions (BRRC, 1988b). No treatment related increases in numbers of micronuclei in PCE's of Swiss-Webster mice were observed after intraperitoneal administration at concentrations of 87.5, 175 and 280 mg/kg bw. Relatively high dose levels of the test compound were tested up to 80% of the LD50 with no indication of significant induction of micronuclei. The PCE/NCE ratio was reduced at the highest concentration, 48 h exposure and at all doses, 72 h exposure, indicating exposure of the target tissue to the test substance. The test compound is considered to be negative for the induction of micronuclei under the conditions of this test.

 

In conclusion, no evidence of mutagenicity or clastogenicity was observed in any of the available in vitro and in vivo studies. 

Justification for classification or non-classification

The available data on genetic toxicity of the analogue substance N-(3 -(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) and the registered substance do not meet the criteria for classification according to Regulation (EC) No. 1272/2008 and are therefore conclusive but not sufficient for classification.