Tetravinylsilane

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:

From 2017-12-04 to 2017-12-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 13, 2004

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Lot number: 707001
Purity: 98.6%
Appearance: Clear and colourless liquid
Storage conditions: Cold and dark storage place

Analytical monitoring:

yes

Details on sampling:

Samples were taken at the start and end of exposure. Another solution sampled separately from the preparation container (at the start of exposure) was taken for measuring concentration of test item in test solution, with equal volume of mixed solution taken from the middle layer of the test solution in test vessels in each test level (at the end of exposure). Sample volume was approximately 10 mL (for all test levels).

Vehicle:

no

Details on test solutions:

The test sample (110 mg) and dechlorinated tap water (1100 mL) were mixed to prepare the nominal concentration of 100 mg/L and were gently stirred with a magnetic stirrer for 48 hours at about 20°C. The solution was then allowed to settle for 1 hour at about 20°C and the middle layer collected as the stock solution. Required volumes of the stock solution and dilution water processing similar to the control without the test item were mixed and stirred in a preparation container to prepare the test solution which was divided into each test vessel (50 mL stoppered Erlenmeyer flasks (closed vessels)).

Test organisms (species):

Daphnia magna

Details on test organisms:

Source of supply: The University of Sheffield, UK
Supplied date: July 9, 1990

Acclimation:
Young daphnids used for testing were produced by parents that were cultured in the testing laboratory. The parents were bred in the same quality of water (dechlorinated tap water), water temperature (20±1°C) and photoperiod (16-hour light/8-hour dark) as used in the test.

Selection of young daphnids:
Young daphnids selected for testing were < 24-hours old and were randomly allocated to test groups.

Test type:

static

Water media type:

freshwater

Remarks:

(dechlorinated tap water)

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

None

Post exposure observation period:

NA

Hardness:

32 mg/L

Test temperature:

19.3 - 19.7°C

pH:

7.8

Dissolved oxygen:

> 3 mg/L without aeration

Salinity:

NA

Conductivity:

Not specified

Nominal and measured concentrations:

Measured concentrations (geometric mean): Control, 0.286, 0.458, 0.814, 1.47 and 2.66 mg/L

Details on test conditions:

Control: Dilution water without the test item, which was treated in the same manner as the stock solution except for collecting the middle layer
Replicate: 4 replicates/test level
Number of organisms: 20 daphnids/test level (5 daphnids/test vessel)
Volume of test solution: Approximately 200 mL/test level (approximately 50 mL/test vessel)
Light condition: Room light, 16-hour light/8-hour dark
Feeding: No feeding during test

Test organism observations for immobility and symptoms were conducted at 24 and 48 hours after exposure. Daphnids were considered immobile when they were unable to swim within 15 seconds after gentle agitation of the test vessel.

Dissolved oxygen concentration (dissolved oxygen meter: HQ30d (HACH)), pH (pH meter: HM-21P (DKK-TOA)) and temperature (glass thermometer) were measured at the start and end of exposure. A solution was sampled separately from the preparation container at the start of exposure and one test vessel was sampled in each test level at the end of exposure.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.954 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

1.09 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 0.962-1.24 mg/L

Details on results:

The minimum concentration causing 100% immobility at 48 hours was 1.47 mg/L. Maximum concentration causing no immobility at 48 hours was 0.458 mg/L. Immobility in the control during exposure was 0%, thus meeting the validity criteria of the test (i.e. not more than 10%).

Observed abnormal responses during exposure were immobilisation, lethargic and reduced activity. In the control, no abnormal response (discolour of body, trapping at the surface of the water and so on), which met the validity criteria of the test (i.e. not more than 10%) was observed during exposure.

The measured concentrations of the test item in the test solutions at the start of exposure were 0.303+-2.76 mg/L and those at the end of exposure were 0.269-2.56 mg/L, which were 88.9-93.0% of the concentrations at the start of exposure.

Results with reference substance (positive control):

Periodically, a 48-hour acute immobilisation test of a reference substance (potassium dichromate) using the test organisms is conducted to confirm the reproducibility of the test system, the most recent of which (as of the date of the current study) showed results (48-h EC50 = 0.12 mg/L) within the stipulated range to background data in the testing laboratory.

Reported statistics and error estimates:

The 24-hour EC50 value was calculated by Probit analysis and the 95% confidence limits and the slope of the regression line calculated. The 48-hour EC50 value was calculated by Binominal test. The EC50 was estimated using Microsoft Excel. The estimation of EC50 was performed based on geometric mean of measured concentrations of test solution during exposure.

Immobility

Measured concentration^a (mg/L)	Vessel	24 hours		48 hours
		Number of immobilised daphnids / Total daphnids	Immobility (%)	Number of immobilised daphnids / Total daphnids	Immobility (%)
Control	A	0 / 5	0	0 / 5	0
	B	0 / 5		0 / 5
	C	0 / 5		0 / 5
	D	0 / 5		0 / 5
0.286	A	0 / 5	0	0 / 5	0
	B	0 / 5		0 / 5
	C	0 / 5		0 / 5
	D	0 / 5		0 / 5
0.458	A	0 / 5	0	0 / 5	0
	B	0 / 5		0 / 5
	C	0 / 5		0 / 5
	D	0 / 5		0 / 5
0.814	A	1 / 5	5	2 / 5	25
	B	0 / 5		2 / 5
	C	0 / 5		1 / 5
	D	0 / 5		0 / 5
1.47	A	4 / 5	95	5 / 5	100
	B	5 / 5		5 / 5
	C	5 / 5		5 / 5
	D	5 / 5		5 / 5
2.66	A	5 / 5	100	5 / 5	100
	B	5 / 5		5 / 5
	C	5 / 5		5 / 5
	D	5 / 5		5

^aGeometric mean of the measured concentrations

 

Observed abnormal response

Measured concentration^a (mg/L)	Observed abnormal response (Number of affected test organisms)
	24 hours	48 hours
Control	-	-
0.286	-
0.458	-
0.814	IM(1), RA(6)	IM(5), RA(7)
1.47	IM(19) [LETH(10)], RA(1)	IM(20) [LETH(11)]
2.66	IM(20) [LETH(12)]	IM(20) [LETH(20)]

-: Normal (no abnormal response)

Abbreviation of symptom: IM = Immobilisation, [LETH[ = Lethargic, the severe symptom including immobilisation, RA = Reduced activity

Measured concentrations of test item in test solutions

 

Stock solution content (%)	Measured concentration (mg/L) (Percentage of measured concentration versus that at the start %)
	At start of exposure	At end of exposure	Geometric mean
Control	n.d.	n.d.	-
4.76	0.303	0.269 (88.9)	0.286
8.57	0.479	0.438 (91.5)	0.458
15.4	0.852	0.777 (91.2)	0.814
27.8	1.55	1.40 (90.6)	1.47
50.0	2.76	2.56 (93.0)	2.66

n.d.: <0.05 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 value was determined to be 0.954 mg/L. The minimum test concentration causing 100% immobility at 48-hours was 1.47 mg/L and the maximum test concentration causing no immobility at 48-hours was 0.458 mg/L. The study met the validity criteria set by the guideline and is therefore considered to be valid.

Executive summary:

A study investigating the short-term toxicity of the test item to the freshwater invertebrate, Daphnia magna, exposed to the test item for 48-hours was assessed according to the OECD 202 ‘Daphnia sp. Acute immobilisation test’ Guideline.

 

Tests were conducted within the substance’s limit of solubility and used closed test vessels due to the strong smell of the test item. The measured concentrations of the test item in the test solution during the exposure were within the range of ±20% of that at the start of exposure and the test conditions were within the suitable range. There were no factors which may have affected the reliability of the test.

 

The 24-hour and 48-hour EC50 values of the test item for D. magna were 1.09 mg/L (95% confidence limits: 0.962-1.24 mg/L) and 0.954 mg/L, respectively. The minimum test concentration causing 100% immobility at 48-hours was 1.47 mg/L and the maximum test concentration causing no immobility at 48-hours was 0.458 mg/L.  

Description of key information

A study investigating the short-term toxicity of the test item to the freshwater invertebrate, Daphnia magna, exposed to the test item for 48-hours was assessed according to the OECD 202 ‘Daphnia sp. Acute immobilisation test’ Guideline. The study was conducted at a GLP accredited laboratory and met the validity criteria prescribed in the test guideline and is therefore considered to be valid and reliable.

 

Tests were conducted within the substance’s limit of solubility and used closed test vessels due to the strong smell of the test item. The measured concentrations of the test item in the test solution during the exposure were within the range of ±20% of that at the start of exposure and the test conditions were within the suitable range. There were no factors which may have affected the reliability of the test.

 

The 24-hour and 48-hour EC50 values of the test item for D. magna were 1.09 mg/L (95% confidence limits: 0.962-1.24 mg/L) and 0.954 mg/L, respectively. The minimum test concentration causing 100% immobility at 48-hours was 1.47 mg/L and the maximum test concentration causing no immobility at 48-hours was 0.458 mg/L.  

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.954 mg/L