Triethoxy(vinyl)silane

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Feb - 17 Feb 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Circular on Test Methods of New Chemical Substances (Japan), Alga growth inhibition test

Deviations:

no

GLP compliance:

yes

Remarks:

according to the Japanese GLP Standard

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Melting point: < 0°C
- Boiling point: 123°C
- Vapour pressure: < 2.7 kPa at 25 °C
- Water solubility (under test conditions): low
- Stability in water: Test item is hydrolyzed (half-life: within 30 min)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: sampled directly by each vessel and pre-treatment was not performed
- Sample storage conditions before analysis: no strage before analysis
- Methanol was measured, since the test item was quickly hydrolyzed

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test item was measured and diluted in dilution water by stirring for 120 min

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Alga
- Strain: ATCC22662
- Source (laboratory, culture collection): American Type Culture Collection
- Age of inoculum (at test initiation): after 4-day preculture
- Method of cultivation: on a shaker

ACCLIMATION
- Acclimation period: 4 days (2006-02-10 ~ 2006-02-14)
- Culturing media and conditions (same as test or not): same as test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

23.0 - 23.1 °C (23 ± 2 °C), measured at the study initiation, 24, 48 and 72 hours after exposure

pH:

8.0 - 9.9, measured at the initiation and at the end of the study.

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentration: 89 mg/L (time-weighted mean; the concentration was determined based on the measured concentration of the hydrolysis product, methanol)

Details on test conditions:

TEST SYSTEM
- Test vessel: 500 mL Elenmyer-flask
- Type (delete if not applicable): closed
- Material, headspace, fill volume: glass, 490 mL, 100 mL
- Initial cells density: 5000 cells/mL
- Control end cells density: 855900 ± 20700 cells/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: same medium

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no adjustment
- Photoperiod: continuously
- Light intensity and quality: 65 µE/m2/s

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting chamber; electronic particle counter;

TEST CONCENTRATIONS
- Range finding study: performed twice.
- Test concentrations: 1) 1, 10 and 100 mg/L, 2) 100 mg/L
- Results used to determine the conditions for the definitive study:
1) Inhibition rate was 16% (close system), -42% (open system) in 1 mg/L, 12% (close system), -44% (open system) in 10 mg/L, and 1% (close system), -36% (open system) in 100 mg/L, respectively.
2) Inhibition rate was -14% (close system) and 6% (open system). Measured concentration was 108 mg/L at the study initiation and 87 mg/L in a close system at the end of the study.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (analytical grade)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: the concentration was determined based on the measured concentration of the hydrolysis product, methanol

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: the concentration was determined based on the measured concentration of the hydrolysis product, methanol

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: the concentration was determined based on the measured concentration of the hydrolysis product, methanol

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: the concentration was determined based on the measured concentration of the hydrolysis product, methanol

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no abnormality was observed

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50: 0.428 ± 0.0683 mg/L

Reported statistics and error estimates:

Student's t-test, subsequent to F test for homogeneity of variances.

Table 1. Calculated concentration of the test substance using methanol concentration

Nominal concentration (mg/L)	Mean measured concentration, mg/L (Percent of nominal)				Mean measured concentration (*), mg/L
	0 hour	24 hours	48ours	72ours
Control	< 0.03	< 0.03	< 0.03	< 0.03
100	105 (105	100 (100	75.3 (75)	80.2 (80)	89 (89)

*: Time-weighted mean measured concentration

Table 2. Growth inhibition (%)

Nominal conc. (mg/L) [Mean measured conc. *]	Inhibition rate (%) Growth rate	Inhibition rate (%) Biomass
Control	-	-
100 [89]	0.3	0.5

*: Time-weighted mean measured concentration

Conclusions:

The NOEC of 2768-02-7 to algae was reported to be >89 mg/l for both biomass and growth rate. Due to the rapid rate of hydrolysis, the concentration was determined based on the measured concentration of the hydrolysis product, methanol.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions (No GLP or analysis), study period of 7d but not appropriate for current regulatory purposes days

Qualifier:

according to guideline

Guideline:

other: US EPA 67014-73-0

Deviations:

yes

Remarks:

:7 day exposure period

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

no data

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

no data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Hardness:

no data

Test temperature:

no data

pH:

no data

Dissolved oxygen:

no data

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 0(Control), 25, 100 and 1000 mg/l

Details on test conditions:

TEST SYSTEM

- Test vessel:Flask

- Material: Polycarbonate

- Aeration: no data

- Renewal rate of test solution: static test

- Initial cells density: 50000 cells/ml

- Control end cells density: approx. 2000000 cells/ml

- No. of vessels per concentration (replicates): 3

- No. of vessels per control (replicates): 3


GROWTH MEDIUM

- Standard medium used: sterilised algal broth

- Detailed composition if non-standard medium was used: no data


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: sterilized algal broth

- Culture medium different from test medium: no data

- Intervals of water quality measurement: no data


OTHER TEST CONDITIONS

- Sterile test conditions: yes

- Adjustment of pH: no data

- Photoperiod: no data

- Light intensity and quality: no data


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Growth rate and cell number

- Determination of cell concentrations: counting chamber

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 4.0-10

- Range finding study: no data

Reference substance (positive control):

no

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

210 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: final yield

Remarks on result:

other: 163-276

Duration:

7 d

Dose descriptor:

EC10

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: final yield

Remarks on result:

other: 21-46

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

ca. 25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: final yield

Details on results:

- Exponential growth in the control (for algal test): yes

- Any stimulation of growth found in any treatment: no

Reported statistics and error estimates:

The ECx values were calculated using methods described in the Handbook of Phycological Methods (1973) in conjunction with probit analysis based on Finney's Method (Statistical Methods in Biological Assay, 1952).

The test substance had a negligible effect on exponential growth of the algae.

Validity criteria fulfilled:

yes

Conclusions:

Measured data was not available for triethoxy(vinyl)silane (CAS 78-08-0), therefore data was read across from the comparable substance, trimethoxyvinylsilane (CAS 2768-02-7) A 7-day EC50 value of 210 mg/l and NOEC of 25 mg/l have been reported fot the effects of the test substance on final yield of Pseudokirchnerella subcapitata. It is likely that the test organisms were primarily exposed to the hydrolysis products of the substance.

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

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

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: the concentration was determined based on the measured concentration of the hydrolysis product, methanol

Remarks:

MOE 2006

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: the concentration was determined based on the measured concentration of the hydrolysis product, methanol

Remarks:

MOE 2006

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

210 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: final yield

Remarks on result:

other: 163-276

Remarks:

Dow Corning 1979

Duration:

7 d

Dose descriptor:

EC10

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: final yield

Remarks on result:

other: 21-46

Remarks:

Dow Corning 1979

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: final yield

Remarks on result:

other:

Remarks:

Dow Corning 1979

Description of key information

Key study: A 72-hr NOEC of >= 89 mg/l (growth rate and biomass Pseudokirchneriella subcapitata, Circular on Test Methods of New Chemical Substances (Japan)

Supporting study: A 7-day EC50 of 210 mg/l and NOEC of 25 mg/l h (yield of Pseudokirchneriella subcapitata, US EPA 67014-730), RL2

Additional information

Measured data were not available for triethoxy(vinyl)silane (CAS 78-08-0), therefore data were read across from the analogue substance, trimethoxyvinylsilane (CAS 2768-02-7).

According to Circular on Test Methods of New Chemical Substances (Japan) a 72h NOEC of 89 mg/l was derived concerning the effects of the test substance on growth rate and biomass of Pseudokirchneriella subcapitata (Ministery of the Environment, Government of Japan, 2006c). In the supporting study, a 7-day EC50 value of 210 mg/l and a NOEC of 25 mg/l for the effects of the test substance on final yield of Pseudokirchneriella subcapitata were derived (Dow Corning Corporation, 1979).