Triethoxy(vinyl)silane

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Data waiving:

other justification

Justification for data waiving:

other:

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1993-11-18 to 1993-12-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was well documented and meets generally accepted scientific principles, and conducted in compliance with GLP.

Qualifier:

according to guideline

Guideline:

other: Test for inhibition of oxygen consumption by pseudomonas putida -Huels Method

Principles of method if other than guideline:

Method: Oxygen consumption test (Huls method)

GLP compliance:

yes

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method: nonylphenol ethoxylated propoxylated (EO 10Mol PO 5Mol) used as solubilising agent

Test organisms (species):

Pseudomonas putida

Test type:

static

Water media type:

freshwater

Total exposure duration:

5 h

Post exposure observation period:

At the end of testing HCl was added to stop biochemical processes.

Test temperature:

23.9-25.1°C

Nominal and measured concentrations:

500,1000, 1500 and 2000 µl/l

Details on test conditions:

TEST SYSTEM

- Test vessel:

- Type (delete if not applicable): closed

- Material, size, headspace, fill volume: 100mL glass bottles with ground glass stopper

- No. of vessels per concentration (replicates): Four, two containing HgCl2

- No. of vessels per control (replicates): Nine, four containing HgCl2

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : oxygen content of solutions measured using oxygen electrode.

Reference substance (positive control):

no

Duration:

5 h

Dose descriptor:

EC10

Effect conc.:

1.1 other: ml/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

	Oxygen concentration (µl/L)
	Control	Test substance at concentration:
		500µl/L	1000µl/L	1500µl/L	2000µl/L
Flasks with HgCl2at beginning of test	7.97
	7.92
	7.84	7.77	7.68	7.57	7.59
	7.87	7.81	7.70	7.66	7.50
Average value	7.90	7.79	7.69	7.62	7.55
Flasks without HgCl2at end of test	3.79
	3.74
	3.81	3.78	3.93	4.05	4.12
	3.81	3.84	4.06	4.25	4.05
Average value	3.79	3.81	4.00	4.15	4.09
O2Consumption during incubation	4.11	3.98	3.70	3.47	3.46
Absolute difference during incubation		0.13	0.42	0.64	0.65
% effect during incubation		3.2	10.2	15.7	15.9

Validity criteria fulfilled:

yes

Conclusions:

Measured data was not available for triethoxy(vinyl)silane. Therefore read across of data from the comparable substance, trimethoxyvinylsilane was considered. A EC10 of 1.1 ml/l for toxicity to microorganisms were determined in a reliable study conducted in compliance with GLP.

Reference 3

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: The result is sourced from secondary literature (Handbook). The original reference was not available for review and no further information is available.

Qualifier:

according to guideline

Guideline:

other: TSCA guidelines

Deviations:

not specified

GLP compliance:

not specified

Test organisms (species):

other: Non-acclimated bacteria

Dose descriptor:

IC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

not specified

Validity criteria fulfilled:

not specified

Conclusions:

An IC 50 value of > 1000mg/l for non-acclimated bacteria is reported in secondary literature (Handbook). The original reference was not available for review and no further information is available. The reliability of this result is not assignable.

Reference 4

Endpoint:

activated sludge respiration inhibition testing

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

Please refer to overall summary (IUCLID Section 6.1) and attached justification for grouping in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

5 h

Dose descriptor:

EC10

Effect conc.:

1.1 other: ml/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Description of key information

NOEC of 100 mg/l (OECD 301F)
EC10 of 1.1 ml/l (1.1. ml = ca 1g calculated from density; RL2)

Additional information

The toxicity of triethoxy(vinyl)silane (CAS 78-08-0) to microorganisms was reported in secondary literature, with an IC50 of > 1000 mg/l (Chandra, 1997). However no further information is available and therefore the results are not reliable and can be used only as supportive information.

As no reliable data were available for triethoxy(vinyl)silane (CAS 78-08-0), data were read across from the analogue substance, trimethoxy(vinyl)silane (CAS 2768-02-7). Both substances share the same silanol hydrolysis product, vinylsilanetriol. Further hydrolysis products are ethanol and methanol respectively. Ethanol and methanol are readily biodegradable, are well characterised and are not expected to have adverse effects on microorganisms in a sewage treatment plant. Both triethoxy(vinyl)silane (CAS 78-08-0) and trimethoxy(vinyl)silane (CAS 2768-02-7) are within an analogue group of substances that exhibit no evidence of significant toxicity to microorganisms. It is therefore considered valid to read-across the results for trimethoxy(vinyl)silane to fill the data gap for the target substance.

One study testing the respiration inhibition of the single organism Pseudomonas putida by trimethoxy(vinyl)silane is available (Hüls AG, 1993c). The study resulted in an EC10 of 1.1 ml/l (1.1. ml = ca 1g calculated from density) based on oxygen consumption. The study was conducted in compliance with GLP.

Good quality data for the analogue substance, trimethoxy(vinyl)silane (CAS 2768-02-7), have been read across from the biodegradation study. The reliable biodegradation study was performed according to OECD 301 F. The biodegradation rate in the toxicity control shows a similar course of biodegradation as the two controls containing the reference item, only. Within 14 days of exposure, a biodegradation of 64% of the reference substance was observed. Thus, according to guideline the test item shows no inhibitory effect on activated sludge microorganisms up to a concentration of 100 mg/l. The NOEC of 100 mg/l can be used for the PNEC derivation. It can be concluded that inhibition of the degradation activity of activated sludge is not anticipated due to the results of the biodegradation study and the single organisms is not used for the evaluation of a sewage treatment plant.