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

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2012-12-10 to 2012-01-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

adopted 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

Version / remarks:

adopted 1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Supersaturated solution was prepared (nominally 1000 mg/L). Non-dissolved material was removed by filtration. The following test solutions were prepared by appropriate dilution:
7.9, 11.9, 17.8, 26.7, 40.0, 60.0, 80.0 and 100.0 % v/v saturated solution.
- Sampling method: 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:

yes

Details on test solutions:

Because the test item is poorly soluble in water and media preparation is not possible by direct addition at the test concentrations used, therefore, serial dilution of the Water Accommodated Fraction (WAF, according to OECD No. 23., Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, section 3.1.2 Media preparation methods) of a properly prepared stock solution will be used for media preparation as follows:
A supersaturated solution (nominally 1000 mg/L, simulating worst-case scenario conditions) was prepared by dispersing/dissolving the test item amount into the test medium (ISO medium) one day before the start of the study using approx. 10 minutes ultrasonic dispersion. This solution was shaken for about 24 hours and thereafter the non-dissolved test material was removed by filtration through a fine (pore size: 0.2 µm) membrane filter to give the 100 % v/v saturated solution. The test solutions will be prepared by appropriate diluting of the stock solution. The test solutions were prepared just before introduction of test animals (start of the renewal periods).

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: The test fish were bred and held in Fish Laboratory of TOXI-COOP Zrt. (8237 Tihany, Klebelsberg K. u. 3.).
- Age at study initiation: Juveniles
- Length at study initiation: 2 ± 1 cm
- Method of breeding: similar conditions (water temperature, pH, oxygen concentration etc.) and in the same type of water as that used in the experiment
- Feeding during test: no

ACCLIMATION
- Acclimation period: no acclimatization period

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

approx. 249 mg/L CaCO3

Test temperature:

21 – 25 °C

pH:

7.55 - 7.92

Dissolved oxygen:

63.8 - 97.5 %

Nominal and measured concentrations:

Nominal concentrations: 7.9, 11.9, 17.8, 26.7, 40.0, 60.0, 80.0 and 100.0 % v/v saturated solution.
Following analytical determination most of the test concentrations were below the limit of quantification when sampled at the start of the test and at the end of the water renewal period. Thus, the results were based on the respective loading rates.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquariums with 1.5 litre test liquid, covered with glass lids
- Renewal rate of test solution: 24 hours
- No. of organisms per vessel: 7 animals
- No. of vessels per concentration: one replicate
- No. of vessels per control: one replicate
- No. of vessels per vehicle control: one replicate
- Additional test solution control group: An additional test item solution control group (1.1 mg/L) without addition of fish was included in the experiment and analysed at the same occasions as the test concentrations in order to check the possibility of the adsorption of test item on test animals.
- Biomass loading rate: 1.0 mg/L

TEST MEDIUM / WATER PARAMETERS
- in accordance to the guideline

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light: 8 h dark

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Test concentration based on loading range

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 - <= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Test concentration based on loading range

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 100 - <= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Test concentration based on loading range

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Test concentration based on loading range

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Test concentration based on loading range

Details on results:

A single fish was found dead (14 % mortality) during the test (at the 72-h observation period) in the highest test concentration of 100 v/v saturated solution (nominal). Sub-lethal effects of swimming problems (i.e. off-balance, swimming in lateral position, whirling) and reduced swimming activity were additionally noticed at this test concentration.
In the controls and in the lower concentrations (7.9 - 80 % v/v saturated solution (nominal)) no mortality was observed. Sub-lethal effects of reduced and slightly reduced swimming activity and staying at the bottom of the aquarium were observed in the concentration range of 40 to 80 % v/v saturated solution (nominal). However, these slight symptoms could not be considered as significant toxic effects. Accordingly, the No Observed Effect Concentration (NOEC) was determined to be in the concentration range of 100 - 1000 mg/L (loading rate), the 96-h LC50 value of the test item was determined to be > 1000 mg/L (loading rate).

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this acute fish toxicity study the observed results were the following: The 96-h LC50 value was determined to be > 1000 mg/L (loading rate), the 96-h NOEC was determined to be in the range of 100 to 1000 mg/L (loading rate).

Executive summary:

Acute toxicity of the test item was assessed with acute fish toxicity test on Zebrafish (Danio rerio) over an exposure period of 96 hours in a semi-static system according to OECD guideline 203 and EU method C.1. Due to the test item's 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 96-hour semi-static acute toxicity test on Zebrafish (Brachydanio rerio). Based upon the results from the preliminary experiment, nominal concentrations of 7.9, 11.9, 17.8, 26.7, 40.0, 60.0, 80 and 100 % v/v saturated solution were investigated in the main study. Most of the test concentrations were below the limit of quantification. Thus, the 96-h LC50 value for the test item was determined to be > 1000 mg/L based on the loading rate. The highest test concentration causing no mortality within the test period (96-h LC0) was determined to be between 100 – 1000 mg/L based on the loading rate. The NOEC was determined to be in the range of 100 – 1000 mg/L (loading rate), while the LOEC was determined to be 1000 mg/L (loading rate).

Description of key information

Under the conditions of the acute fish toxicity study, the observed results were the following: The 96-h LC50 value was determined to be > 1000 mg/L (loading rate), and the 96-h NOEC was determined to be in the range of 100 to 1000 mg/L (loading rate).

Additional information

Acute toxicity of the test item was assessed with acute fish toxicity test on Zebrafish (Danio rerio) over an exposure period of 96 hours in a semi-static system according to OECD guideline 203 and EU method C.1. Due to the test item's 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 96-hour semi-static acute toxicity test on Zebrafish (Brachydanio rerio). Based upon the results from the preliminary experiment, nominal concentrations of 7.9, 11.9, 17.8, 26.7, 40.0, 60.0, 80 and 100 % v/v saturated solution were investigated in the main study. Most of the test concentrations were below the limit of quantification. Thus, the 96-h LC50 value for the test item was determined to be > 1000 mg/L based on the loading rate. The highest test concentration causing no mortality within the test period (96-h LC0) was determined to be between 100 – 1000 mg/L based on the loading rate. The NOEC was determined to be in the range of 100 – 1000 mg/L (loading rate), while the LOEC was determined to be 1000 mg/L (loading rate).