Trimethoxyvinylsilane

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993-06-01 to 1993-06-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The concentration of hydrolysis products in stock solution determined by Total Organic Carbon analysis. The stock solution concentration (464 mg/l equivalent to a test substance concentration of 1145 mg/L) was used as the basis for determining the concentrations in the test media.

Vehicle:

no

Details on test solutions:

- Method: Test media prepared by dilution of a 1000 mg/L stock solution prepared by mixing for 18 h followed by filtration. TOC concentration of stock solution determined.

- Treatments: Control and nominal test concentrations of 57, 80, 115, 160, 229, 321 and 458 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Common name: Daphnia magna

- Strain: Clone 5

- Source: Stock culture

- Age at study initiation (mean and range, SD): <24 h

- Method of breeding: Parthenogenetic reproduction

- Feeding during test: None


ACCLIMATION

- Acclimation conditions (same as test or not): yes

- Type and amount of food: sufficient to be consumed each day leaving no residue

- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

The sum of the Ca2+ and Mg2+ ions was 2.5 mmol

Test temperature:

20 ±1ºC

pH:

7.0 - 7.2

Dissolved oxygen:

6.5 - 8.1 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

Control and nominal test concentrations of 57, 80, 115, 160, 229, 321 and 458 mg/L.

Details on test conditions:

TEST SYSTEM

- Test vessel:

- Type: open

- Material, size, headspace, fill volume: glass cylinder containing 10 ml of test medium

- Aeration: none

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Elendt M4 medium

- Intervals of water quality measurement: end of test


OTHER TEST CONDITIONS

- Photoperiod: Dark


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilization after 24 and 48 h exposure

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 1.4


STATISTICS

EC50 and confidence interval determined by Probit analysis

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

297.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 223.9 - 224.2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

168.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 126.9 - 224.2

Details on results:

- Mortality of control: 0

Results with reference substance (positive control):

- EC50: >0.9, <1.9 mg/L

Reported statistics and error estimates:

The EC50 value and its 95% confidence interval was calculated by Probit analysis.

Table 1. Test results

Nominal test substance concentration (mg/L)	Percentage immobile Daphnia after 24 hours	Percentage immobile Daphnia after 48 hours
0 (Control)	0	0
57	5	25
80	5	25
115	5	35
160	0	35
229	25	45
321	55	75
458	90	100

Validity criteria fulfilled:

yes

Conclusions:

A 48-h EC50 value of 168.7 mg/L has been determined for the effects of the test substance on mobility of Daphnia magna. A NOEC was not determined in the test. It is likely that the test organisms were primarily exposed to the hydrolysis products of the substance.

Description of key information

48-hour EC₅₀: 168.7 mg/L for effects of the test substance on mobility of Daphnia magna. It is likely that the test organisms were primarily exposed to the hydrolysis products of the substance. The EC₅₀ is equivalent to 121 mg/L when expressed in terms of the silanol hydrolysis product, vinylsilanetriol (CAS 143-48-6).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

121 mg/L

Additional information

A 48-hour EC₅₀ value of 168.7 mg/L (nominal concentration) has been determined for the effects of the test substance on mobility of Daphnia magna. It is likely that the test organisms were primarily exposed to the hydrolysis products of the substance. The results may be expressed in terms of the silanol hydrolysis product by adjusting for the respective molecular weights: MW hydrolysis product/MW parent * E(L)C₅₀ or NOEC value, thus 106.15/148.24 * EC₅₀ of 168.7 mg/L = 121 mg/L as vinylsilanetriol (CAS 143-48-6).

 

The results of this test were selected in preference to those of four other tests because a definitive EC₅₀ value was determined and it was judged to be more reliable.

 

The following result is from a reliable study included as supporting data:

 

48-hour EC₅₀ >100 mg/L for effects of the test substance on mobility of Daphnia magna (Dow Corning Corporation, 1979).

 

Three further studies, for which reliability could not be ascertained, are also included in the dataset:

 

48-hour EC₅₀ >100 mg/L for effects of the test substance on mobility of Daphnia magna (Bement, 2001).

 

EC₅₀ 360 mg/L for effects of the test substance on mobility of Daphnia magna (Chandra, 1997).

 

48-hour EC₅₀ >100 mg/L for effects of the test substance on mobility of Daphnia magna (MOE Japan, 2005).