2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-methylphenyl acrylate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Non-GLP guideline study without analytical measurements.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted: 13 April 2004

GLP compliance:

no

Remarks:

The study was not conducted in accordance with GLP since it was originally used for screening purposes of environmental hazards at the manufacturing plant.

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test solution was prepared as water accommodated fraction (WAF) referred to OECD Guidance Document No. 23: 100.6 mg of the test substance was dissolved with the dilution water to make volume to 1000 mL, stirred with a magnetic stirrer for 48 h at the test temperature and then left at rest for 1 hour. Almost all of the test substance was floating on the water surface and partially observed on the bottom of vessel or intermediate water. Finally the test solution was prepared by vacuum filtration with 0.45 μm membrane filter (Mixed Cellulose Ester, Advantec Toyo Kaisha, Ltd.). The test solution used for water exchange at 24 hour after initiation of exposure was also prepared independently under the same condition. Appearance of the test solutions was recorded just after preparation.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Originally obtained from National Institute for Environmental Studies, Japan (28 Oct 1996)
- Feeding during test: none
- Age: < 24 h

ACCLIMATION
- Acclimation period: 01 - 16 Mar 2016
- Acclimation conditions: The parents indicated good reproductive conditions, since no sign of abnormality such as production of ephippia was observed.
- Type and amount of food: Commercial condensed live Chlorella and YCT (yeast, dried alfalfa and Tetramin); 0.1 – 0.2 mg C (organic carbon) / daphnid / day
- Feeding frequency: daily
- Health during acclimation (any mortality observed): Mortality of the parent daphnids during the acclimation period was 0%.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

250 mg/L as CaCO3

Test temperature:

20.1 - 20.3 °C

pH:

7.7 - 7.9

Dissolved oxygen:

8.7 - 8.8 mg O2/L

Nominal and measured concentrations:

nominal: control, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL volume glass beaker
- Type (delete if not applicable): covered with a transparent plastic lid
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): every 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 16 daphnids/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Artificial reconstituted water, Elendt M4
- Culture medium different from test medium: same as test
- Intervals of water quality measurement: Water quality was measured regularly.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h darkness
- Light intensity: Room lighting (5.00 – 9.96 μE/m²/s), 16 h light / 8 h dark cycle

EFFECT PARAMETERS MEASURED
- Number of immobilized daphnids and other toxic symptoms compared to the control were recorded at 24 and 48 h after initiation of exposure

Reference substance (positive control):

yes

Remarks:

potassium dichromate (tested regularly)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Other biological observations: No other biological effects were recorded.
- Mortality of control: 0%
- Other adverse effects control: No other adverse effects were recorded.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 (48 h): 0.99 mg/L (Study termination date: 25 Feb 2016)

Reported statistics and error estimates:

No statistical analysis was necessary since no effects on fish were observed.

Table 1: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more that 10% of the daphnids should have been immobilized.	0%	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	8.7 - 8.8 mg/L	yes

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Description of key information

EC50 (48 h) > 100 mg/L (nominal, Daphnia magna, OECD 202)

Additional information

One experimental study is available investigating the toxicity of 2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-methylphenyl acrylate (CAS 61167-58-6) to the freshwater invertebrate Daphnia magna. The study was performed according to OECD 202 (non-GLP) as a limit test with a filtered test solution of 100 mg/L under semi-static conditions. An appropriate amount of the test item was added to test medium followed by a two day stirring period. Almost all of the test substance was floating on the water surface and partially observed on the bottom of vessel or intermediate water. Finally the test solution was prepared by vacuum filtration with 0.45 μm membrane filter. After this additional step the test solutions were clear and colorless. In this study no analytical verification of the test item concentrations was performed. However, since the preparation of test solutions is nearly comparable to the one in the available short-term study with fish it is assumed that the measured concentrations in test medium will be in a comparable range. After 48 h no immobilization was recorded and the EC50 (48 h) was reported as > 100 mg/L (nominal). All validity criteria of the study are met.