4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl

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:

September 06, 2011 - January 23, 2012

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:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Council Regulation (EC) No. 440/2008 laying down test methods pursuant to Regulation (EC) No. 1907/2006 of the European Parliament and the council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Remarks:

The test item concentration in the reconstituted water was not quantified at the start and the end of this study. Because of the low water solubility (0.0028 mg/L), the compound cannot be detected with standard analytical methods.

Vehicle:

yes

Details on test solutions:

Macro nutrients (mg/L)
CaCI2 •2H20 293.80
MgSO4•7H20 123.30
NaHCO3 64.80
KCI 5.80
Na2SiO3•9H20 10.00
NaNO3 0.27
KH2PO4 0.14
K2HPO4 0.18

Trace elements (mg/L)
B 0.5000
Fe 0.2000
Mn 0.1000
Li, Rb and Sr 0.0500
Mo 0.0250
Br 0.0125
Cu and Zn 0.0063
Co and I 0.0025
Se 0.0010
V 0.0003

Macro nutrients (mg/L)
Na2EDTA • 2H20 2.50

Vitamins (µg/L):
Thiamine 75.00
B12 1.00
Biotin 0.75

- pH: 7.70

Preparation of the Test Item:
The test medium (reconstituted water and test material) was freshly prepared. Therefore, the calibrated flask with test medium was treated in an ultrasonic device for 1 hour. Subsequently, the preparation was stirred with a magnetic stirrer for further 23 hours. The formulation was then passed through a single use syringe filter (pore size 0.2 µm). The filtrate was used for the study.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna Straus
Culture conditions: The clone is bred in the laboratories of Merck KGaA (room 2068).
Parental daphnids are used for reproduction until they are about 6 weeks old. Thereafter, they are replaced by neonates.
Daphnids are kept individually in 100 mL glass vessels containing approximately 60 mL reconstituted water (ELENDT M4 medium) at a water temperature of 20 ± 2°C and a 16 hour light and 8 hour dark regime to ensure similar conditions as in the experiment. Offspring are removed from the vessels at least twice per week.
Feeding: The parental daphnids are fed ad libitum with unicellular green algae Desmodesmus subspicatus three times per week.
Age: Offspring less than 24 hours old were used for the study.
Acclimation period: same as test

Feeding during test: None

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21°C

pH:

7.67 - 7.79

Dissolved oxygen:

7.88 - 8.12

Nominal and measured concentrations:

Nominal 100 mg/L

Details on test conditions:

EXPOSURE:
The study was performed in an air-conditioned room. At the start of the experimental phase, 5 daphnids were placed into test vessels with 10 mL of reconstituted water (4 vessels / control group) or test medium (4 vessels / test material group). The daphnids were not fed, and the control medium and test medium were not aerated during the test.

The test was performed as a static test in open vessels.

The duration of exposure was 48 hours. During the exposure period, the mobility of the daphnids was assessed daily, i.e. after 24 and 48 hours.

NO. OF DAPHNIDS:
Control Group: 20 daphnids
100 mg/L: 20 daphnids

CONCENTRATION(S)
In a pre-test no immobilization was observed at a concentration of 100 mg/L under open static conditions. Therefore, the solution of a nominal test item concentration of 100 mg/L was tested in the present study.

For the control, reconstituted water (ELENDT M4 medium) was used.

VEHICLE
Reconstituted water (ELENDT M4 medium) was used as vehicle.

Macro nutrients (mg/L)
CaCI2 •2H20 293.80
MgSO4•7H20 123.30
NaHCO3 64.80
KCI 5.80
Na2SiO3•9H20 10.00
NaNO3 0.27
KH2PO4 0.14
K2HPO4 0.18

Trace elements (mg/L)
B 0.5000
Fe 0.2000
Mn 0.1000
Li, Rb and Sr 0.0500
Mo 0.0250
Br 0.0125
Cu and Zn 0.0063
Co and I 0.0025
Se 0.0010
V 0.0003

Macro nutrients (mg/L)
Na2EDTA • 2H20 2.50

Vitamins (µg/L):
Thiamine 75.00
B12 1.00
Biotin 0.75

- pH: 7.70
- O2-Concentration: 8.12 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: 48 h


OTHER TEST CONDITIONS
- Photoperiod: 16h light / 8h dark

References:

ELENDT, B.-P. Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus.
Protoplasma 154, 25-33, 1990

Reference substance (positive control):

no

Remarks:

No positive control used in this study. The accuracy and reliability of the test method is demonstrated periodically as recommended by guidelines with potassium dichromate.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: EC50 > 0.0028 mg/L (limit of water solubility)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: EC50 > 0.0028 mg/L (limit of water solubility)

Details on results:

Under the conditions of the present study, an aqueous solution of nominal 100 mg/L of the test item revealed no aquatic toxicity up to the limit of water solubility.


The 48h EC50 exceeded the water solubility of 0.0028 mg/L (nominal >100 mg/L) and, thus, could not be determined in this study.

- Behavioural abnormalities: no
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no

Results with reference substance (positive control):

Potassium dichromate:
24 h EC50 0.954 mg/L
48 h EC50 0.688 mg/L

Under the given experimental conditions, the test material Art. 104864 (Potassium dichromate) showed a 24 h EC50 value which was within the range of the published data of 0.6 to 2.1 mg/L (OECD Guideline No. 202).

Validity criteria fulfilled:

yes

Conclusions:

The test item dissolved in reconstituted water, was tested in an open static test system. An aqueous solution of 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 24 hour and 48 hour EC50 could not be determined, because it exceeded the maximum solubility of the test material in reconstituted water (EC50 > 100 mg/L).

Executive summary:

Objective

The objective of this study was to determine the effect of the test itemon the immobilization of Daphnia magna.

Study Design

Juvenile daphnids were exposed to a nominal test item concentration of 100 mg/L (limit test) in an open static system. 20 daphnids, divided into four replicates, each with five animals were used in the test item group and the control group. The daphnids were observed for immobilization after 24 and 48 hours of exposure.

Results

The test material concentration in the reconstituted water was not quantified at the start and the end of this study due to the low water solubility (0.0028 mg/L). Because of the low water solubility, the compound cannot be detected with standard analytical methods. The development of an analytical method with a sufficiently low detection and quantification limit is complex. Due to the absence of any adverse effects at the saturation concentration, the study was performed without analytical concentration verification.

No effect on the mobility of the daphnia was observed at a nominal concentration of 100 mg/L.

For the test itemthe following EC50 values were determined:

EC50 (24h) >0.0028 mg/L (nominal >100 mg/L)

EC50 (48h) >0.0028 mg/L (nominal >100 mg/L)

Conclusion

The test item dissolved in reconstituted water, was tested in an open static test system. An aqueous solution of 100 mg/L of the test material revealed no aquatic toxicity in the test system. The 24 hour and 48 hour EC50 could not be determined, because it exceeded the maximum solubility of the test material in reconstituted water (EC50 > 100 mg/L).

Description of key information

The informtion for this endpoint study record was obtained from an experimental study. The OECD GLP criteria were met and the methods applied are fully compliant with OECD TG 202.

EC50 (48h) > 100 mg/L (nominal)