[3-(2,3-epoxypropoxy)propyl]triethoxysilane

Genetic toxicity: in vitro

Administrative data

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:

April 25 2001 - May 11 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Commission Directive 2000/32/EC L1362000

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: EPA Code of Federal Regulations 40 Part F

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

[3-(2,3-epoxypropoxy)propyl]triethoxysilane

EC Number:

220-011-6

EC Name:

[3-(2,3-epoxypropoxy)propyl]triethoxysilane

Cas Number:

2602-34-8

Molecular formula:

C12-H26-O5-Si

IUPAC Name:

triethoxy[3-(oxiran-2-ylmethoxy)propyl]silane

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital and beta-naphthoflavone induced rat liver S9

Test concentrations with justification for top dose:

33-5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: requested by sponsor

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 1535 and TA 100 without metabolic activation

Controls 2

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine

Remarks:

TA 98 and TA 1537 without metabolic activation

Controls 3

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

TA 102 without metabolic activation

Controls 4

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene 10 µg/plate TA 102, 2.5 µg/plate all other strains

Remarks:

with metabolic activation in all strains

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

SELECTION AGENT (mutation assays): histidine-deficient agar

NUMBER OF REPLICATIONS: triplicate plates; the pre-experiment was reported as part of the main experiment as no relevant toxic effects were observed, and the substance was tested up to limit concentrations.

DETERMINATION OF CYTOTOXICITY
- Method: other: condition of bacterial lawn; reduction in number of revertants. An initial test for cytotoxicity was performed using S. typhimurium strains TA 98 and TA 100.

OTHER: ACTIVATION:
Phenobarbital and beta-naphthoflavone induced rat liver S9 (30.8 mg/ml protein); S9 mix contained 15% v/v S9 and included glucose-6-phosphate and NADP as co-factors. 0.5 ml S9 mix was added to overlay agar, bacterial suspension and test or control solution giving a final concentration of approximately 3%.

Evaluation criteria:

A substance is considered positive if there is a dose-related reproducible increase in the number of revertants exceeding twice (TA 98, TA 100, TA 102 or three times (TA 1535, TA 1537) the solvent control value in more than one concentration.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium, other: TA 100 and TA 1535

Metabolic activation:

with and without

Genotoxicity:

positive

Remarks:

effect was greater in the presence of metabolic activation

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium, other: TA 98, TA 102, TA 1537

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:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: no information
- Effects of osmolality: no information
- Evaporation from medium: no information
- Water solubility: not relevant
- Precipitation: none observed
- Other confounding effects: none

RANGE-FINDING/SCREENING STUDIES: no toxicity was observed in the initial toxicity experiment; the pre-experiment was reported as part of the main experiment as no relevant toxic effects were observed, and the substance was tested up to limit concentrations.

COMPARISON WITH HISTORICAL CONTROL DATA: The revertant colony counts of positive control in strain TA 100 exceeded the historical range. This is not considered to compromise the study as fluctuations in positive response are not uncommon in plasmid carrying strains.

ADDITIONAL INFORMATION ON CYTOTOXICITY: no cytotoxicity was observed.

Any other information on results incl. tables

Plate incorporation assay: revertants per plate (mean of three plates)

Concentration µg/plate	TA 1535		TA 1537		TA 98		TA 100		TA 102
	-MA	+MA	-MA	+MA	-MA	+MA	-MA	+MA	-MA	+MA
Negative control	12	12	11	14	27	34	163	169	206	251
Solvent control	12	15	9	13	27	31	151	174	245	248
Positive control	771	320	47	93	29	32	150	165	1122	856
3	-	-	-	-	29	34	151	168	-	-
10	-	-	-	-	30	32	159	159	-	-
33	13	16	9	14	28	29	155	148	221	282
100	17	25	10	12	26	34	160	171	216	201
333	48	123	10	14	31	32	158	320	211	223
1000	64	265	8	11	29	37	202	488	252	234
2500	143	918	8	14	26	34	272	579	193	221
5000	233	1419	10	13	150	693	1175	991	168	380

Applicant's summary and conclusion

Conclusions:

[3-(2,3-Epoxypropoxy)propyl]triethoxysilane has been tested according to OECD 471 and in compliance with GLP conditions using Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537. A substantial dose-related increase in the number of revertant colonies was observed in the base pair exchange specific strains TA 1535 and TA 100. The effect was more marked in the presence of metabolic activation, but was also observed in the absence of metabolic activation. Appropriate positive and solvent and untreated controls were included and gave acceptable results. It is concluded that the test substance is positive for mutagenicity to bacteria under the conditions of the test.