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

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:

1999-09-02 to 1999-11-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

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

EC Number:

220-780-8

EC Name:

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

Cas Number:

2897-60-1

Molecular formula:

C11H24O4Si

IUPAC Name:

diethoxy(methyl){3-[(oxiran-2-yl)methoxy]propyl}silane

Constituent 2

Reference substance name:

[3-(2,3-epoxypropoxy)propyl]diethoxy(methyl)silane

IUPAC Name:

[3-(2,3-epoxypropoxy)propyl]diethoxy(methyl)silane

Method

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:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

100, 333, 1000, 3333, 5000 μg/ plate

Vehicle / solvent:

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

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

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

All salmonella strains + WP2 uvrA (with activation)

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA 98 (without activation)

Controls 3

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 100, TA 1535 (without activation)

Controls 4

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA 1537 (without activation)

Controls 5

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

WP2 uvrA (without activation)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar ; preincubation

ACTIVATION: The S9 mix contained 10 % S9, 5 mM glucose-6-phosphate, 4 mM β-nicotinamide-adenine dinucleotide phosphate, 8 mM MgCl2 and 33 mM KCl in 100 mM phosphate buffer at pH 7.4.

DURATION
- Preincubation period: 60 minutes

- Expression time (cells in growth medium): 48 to 72 hours

NUMBER OF REPLICATIONS: 3 plates for each test concentration

DETERMINATION OF CYTOTOXICITY
- Method: Background lawn analysis

Evaluation criteria:

A result is positive if the number of revertants is significantly increased compared with the solvent control to at least 2-fold of the solvent control for TA 98, TA 100 and WP2 uvrA and 3-fold of the solvent control for TA 1535 and TA 1537.

Cytotoxicity is defined as a reduction in the number of colonies by >50% compared with the solvent control and/or a sparse background lawn.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduced background lawn3333 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

2.1 - 3.1-fold increase in revertants

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduced background lawn 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

4.1 - 9.5-fold increase in revertants

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduced background lawn 3333 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

13.1 - 17-fold increase in revertants

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 5

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

10.4 - 21.8-fold increase in revertants

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduced background lawn 3333 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 6

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduced background lawn 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 7

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduced background lawn 3333 - 5000 μg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 8

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

3.2 - 4.4-fold increase in revertants

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 9

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

4.7 - 5.2-fold increase in revertants

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

Any other information on results incl. tables

Table 2:  Preliminary toxicity assay for all strains with and without metabolic activation

	TA98			TA100			TA1535
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	14	26	No	171	160	No	23	15	No
6.7	15	NC**	No	183	147	No	20	17	No
10	14	12	No	167	187	No	25	19	No
33	12	26	No	173	204	No	24	14	No
67	22	24	No	205	175	No	22	20	No
100	16	19	No	209	190	No	26	22	No
333	12	18	No	325	193	No	36	22	No
667	12	22	No	374	186	No	40	22	No
1000	18	22	No	614	188	No	50	27	No
3333	17	18	No	862	324	No	237	37	No
5000	17	20	No	928	462	No	418	97	No

*solvent control with DMSO

**NC = No count due to procedural error in which plate did not receive an aliquot of tester strain

Table 2:  Preliminary toxicity assay for all strains with and without metabolic activation

	TA1537			WP2 uvrA
Conc. (µg/plate)	— MA	+ MA	Cytotoxic (yes/no)	— MA	+ MA	Cytotoxic (yes/no)
0*	13	13	No	22	17	No
6.7	12	15	No	17	11	No
10	12	19	No	14	13	No
33	11	14	No	14	11	No
67	12	13	No	13	17	No
100	10	6	No	18	13	No
333	15	15	No	21	22	No
667	11	12	No	14	17	No
1000	13	10	No	27	23	No
3333	24	10	No	40	24	No
5000	20	12	No	38	31	No

*solvent control with DMSO

Table 3: Experiment 1 Preincubation 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*	32	36	No	100	118	No	14	10	No
100	26	32	No	149	110	No	26	12	No
333	24	33	No	211	108	No	54	22	No
1000	22	28	No	453	127	No	87	28	No
3333	27**	35	Yes	705**	249	Yes	145**	104	Yes
5000	28**	26	Yes	948**	363	Yes	120**	170	Yes
Positive control	640	544	No	410	522	No	248	78	No

*solvent control with DMSO

**moderately reduced background lawn

***extremely reduced background lawn

Table 3: Experiment 1 Preincubation 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*	13	19	No	12	13	No
100	13	16	No	10	10	No
333	13	22	No	15	15	No
1000	16	9	No	26	18	No
3333	9**	18	No	62	22	No
5000	6***	20	Yes	58	42	No
Positive control	829	89	No	188	54	No

*solvent control with DMSO

**moderately reduced background lawn

***extremely reduced background lawn

Table 4: Experiment 2 Preincubation 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*	12	18	No	125	138	No	9	9	No
33	11	19	No	135	190	No	10	6	No
100	13	18	No	139	121	No	13	12	No
333	12	17	No	196	121	No	32	14	No
1000	11	15	No	350	145	No	45	19	No
3333	14**	13	Yes	383**	270	Yes	141	67	No
5000	6***	18**	Yes	518***	288**	Yes	196**	118	Yes
Positive control	527	597	No	378	622	No	165	32	No

*solvent control with DMSO

**moderately reduced background lawn

***extremely reduced background lawn

Table 4: Experiment 2 Preincubation 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	6	No	11	13	No
33	4	8	No	11	9	No
100	5	5	No	10	11	No
333	4	4	No	9	8	No
1000	2	5	No	16	19	No
3333	4**	6	Yes	50	33	No
5000	5***	6**	Yes	52	57	No
Positive control	396	59	No	207	134	No

*solvent control with DMSO

**moderately reduced background lawn

***extremely reduced background lawn

Applicant's summary and conclusion

Conclusions:

Under test conditions, there was a positive, dose related increase in the number of revertant colonies in Salmonella typhimurium TA 100, TA 1535 and E. coli WP2 uvrA, with and without metabolic activation. The test substance is mutagenic in these tester strains.