1,1'-(1,1,2,2-tetramethylethylene)dibenzene

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 2012-12-11 until 2012-12-13

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:

updated 13th April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

dated May 30, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling preparation:
For determination of the test item concentration, samples were taken from each testing concentration and the control(s) at least at the start and at the end of the test.

Vehicle:

no

Details on test solutions:

Test concentrations were prepared by appropriate diluting of a saturated stock solution. This saturated stock solution was prepared with a loading rate of 1000 mg/L (i.e. 100 % v/v saturated solution) thereby simulating worst-case scenario conditions.
Based on the results of pre-experiments the following five test concentrations were tested in a geometric series (with a separation factor of 1.3): 35.0; 45.5; 59.2; 76.9; and 100.0 % v/v saturated solution (nominal).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age: Less than 24 hours old
- Sex: female
- Feeding, Aeration: None
- Acclimatization: The Daphnia mothers selected ca. one month prior to the start of the test were maintained in ISO medium under test conditions (temperature, light conditions, quality and content of reconstituted water, pH and total hardness).
The test animals were fed daily with a few mL of centrifuged algae (Pseudokirchneriella subcapitata) suspension.
To avoid the necessity of longer adaptation prior to the test, the water used in the test is similar (or the same) to the culture conditions (water temperature, background colour, light intensities).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

294 mg/L as (CaCO3)

Test temperature:

19.5 - 19.7 °C

pH:

7.75 - 8.05

Dissolved oxygen:

7.35 - 8.64 mg/L

Salinity:

not applicable

Nominal and measured concentrations:

The nominal test item concentrations were 35.0; 45.5; 59.2; 76.9; and 100.0 % v/v saturated solution.
The analytical determined test concentrations were below the limits of quantification when sampled at the start and at the end of the test.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers of 50 mL volume with ~40 mL test medium
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED:
NOEC (48 h): No Observed Effect Concentration: highest test concentration at which no significant effect is determined after 48 hours test duration
EC 50: the calculated concentration of the test item which results in a 50 % immobilisation rate
EC 0: highest test concentration without a significant number of immobilised test animals
EC 100: the lowest test concentration at which all test animals are immobile

TEST CONCENTRATIONS
- Range finding study: Two non-GLP preliminary range-finding tests were performed. In the first range-finding test the examined nominal concentrations were: 0.1, 1, 5, 10, 50 and 100 mg test item/L. In the second range-finding test the same concentration range was investigated.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Test concentration based on loading rate

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Test concentration based on loading rate

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Test concentration based on loading rate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Test concentration based on loading rate

Details on results:

Test concentrations were prepared by appropriate diluting of a saturated stock solution. This saturated stock solution was prepared with a loading rate of 1000 mg/L (i.e. 100 % v/v saturated solution) thereby simulating worst-case scenario conditions. Under these conditions all analytical determined test concentrations were below the limits of quantification when sampled at the start and at the end of the water renewal period for all test item concentrations.
Therefore, all biological results are related to loading rate and % of saturated solution (nominal).
All validity criteria were met. There was no significant immobilisation or abnormal behaviour observed in daphnids exposed to each test item concentration or control during the experiment.

Results with reference substance (positive control):

24-h EC50: potassium dichromate 1.03 mg/L, (95 % confidence limits: 0.82 – 1.29 mg/L)

Validity criteria fulfilled:

yes

Conclusions:

For the acute toxicity on Daphnia magna conducted with the test item over an exposure period of 48 hours, the NOEC was determined to be 1000 mg/L (loading rate) and the LOEC, EC100 and the EC50 values were determined to be higher than 1000 mg/L (loading rate).

Executive summary:

The acute toxicity of the test item on Daphnia magna over an exposure period of 48 hours in a static system was assessed according to OECD Guideline 202 and EU method C.2. Due to the test items poor water solubility (maximum water solubility determined to be 0.08 mg/L), a supersaturated solution was prepared thereby simulating worst-case scenario conditions with this 48-hour acute toxicity test with Daphnia magna. Based upon the results of the preliminary range-finding test, nominal concentrations of 35.0, 45.5, 59.2, 76.9 and 100.0 % v/v saturated solution were investigated in the main study.

Under these conditions all analytical determined test concentrations were below the limits of quantification when sampled at the start and at the end of the experiment. Therefore, all biological results are related to loading rate and % of saturated solution (nominal).

The NOEC was determined to be 1000 mg/L (loading rate) and the LOEC, EC100 and the EC50 values were determined to be higher than 1000 mg/L (loading rate).

Description of key information

For the acute toxicity on Daphnia magna conducted with the test item over an exposure period of 48 hours, the NOEC was determined to be 1000 mg/L (loading rate) and the LOEC, EC100 and the EC50 values were determined to be higher than 1000 mg/L (loading rate).

Additional information

The acute toxicity of the test item on Daphnia magna over an exposure period of 48 hours in a static system was assessed according to OECD Guideline 202 and EU method C.2. Due to the test items poor water solubility (maximum water solubility determined to be 0.08 mg/L), a supersaturated solution was prepared thereby simulating worst-case scenario conditions with this 48-hour acute toxicity test with Daphnia magna. Based upon the results of the preliminary range-finding test, nominal concentrations of 35.0, 45.5, 59.2, 76.9 and 100.0 % v/v saturated solution were investigated in the main study.

Under these conditions all analytical determined test concentrations were below the limits of quantification when sampled at the start and at the end of the experiment. Therefore, all biological results are related to loading rate and % of saturated solution (nominal).

The NOEC was determined to be 1000 mg/L (loading rate) and the LOEC, EC100 and the EC50 values were determined to be higher than 1000 mg/L (loading rate).