4-[trans-4-(trans-4-butylcyclohexyl)-cyclohexyl]-1-ethoxy-2, 3-difluorobenzene

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 18, 2007 - February 15, 2008

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:

Official Journal No. L 383 A, December 29, 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch:: E26001046

Analytical monitoring:

no

Remarks:

The test material concentration in the aqueous test medium was not determined due to its low water solubility (< 0.9 mg/L).

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: 7.89


Preparation of the Test Item:
The test medium (reconstituted water and test material) was freshly prepared.
Therefore, the calibrated flask with test material and vehicle, reconstituted water, was treated in an ultrasonic device for 1 hour. Subsequently the preparation was aerated, and 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 Daphnia magna were kept in reconstituted water in glass-vessels. The study was located in an air-conditioned room in the Institute of Toxicology. Lighting was controlled by a timer to provide a 16 hours light - 8 hours dark regime.
Temperature and humidity in the experimental room was measured.
At the start of the experimental phase 5 Daphnia magna were introduced in each test vessel containing 10 ml reconstituted water with or without test material. The vessels were open. The test medium was freshly prepared before the introduction of the young Daphnia magna. The Daphnia magna were not fed, and the test medium was not aerated left during the test.
Feeding: The parental daphnids are fed ad libitum with unicellular green algae Desmodesmus subspicatus
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:

7.80 - 7.99

Dissolved oxygen:

94.2 - 95.4%

Nominal and measured concentrations:

Nominal 100 mg/L

Details on test conditions:

EXPOSURE:
The study was performed in an air-conditioned room. For the study glass vessels containing at least 10 mL either reconstituted water (control group) or test medium (test item group) were used. Each test vessel contained five daphnids. They were not fed and the media were not aerated during the exposure.

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: 7.89
- O2-Concentration: 95.4%
- 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.

Key result

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: Water solubility < 0.9 mg/L

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: Water solubility < 0.9 mg/L

Details on results:

An aqueous solution of nominal 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 48 hour EC50 for Daphnia magna exceeded the maximum solubility of the test material in reconstituted water (< 0.9 mg/L) and, thus, could not be determined in this test.


The 48h EC50 exceeded the water solubility of <0.9 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):

- Results with reference substance valid: yes

The EC50 values with the 95 % confidence intervals:

24 h EC50 0.95 (0.87 – 1.04) mg/L
48 h EC50 0.74 (0.68 – 0.81) mg/L


Conclusions
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 2.4 mg/L (c.f. DIN EN ISO 6341).
This study confirms the sensitivity and reliability of the test system used in the Institute of Toxicology, Merck KGaA.

Study Design

The objective of this study was to determine the acute toxicity of the test material using Daphnia magna.

For this purpose, juvenile Daphnia magna were exposed to an aqueous test material solution over 48 hours, under defined conditions. The study comprised of four test vessels per concentration containing five Daphnia magna each, i.e. 20 Daphnia magna per concentration (test medium group) and control group.

Daphnia magna were exposed to a nominal test material concentration of 100 mg/L (limit test) in an open static system.

Results

After exposure of Daphnia magna o a nominal concentration of 100 mg/L for 48 hours, the following results were obtained:

 

Nominal concentration [mg/L]	No. of Daphnia magna immobilized / exposed
	24 hours	48 hours
0	0/20	0/20
100	0/20	0/20

Daphnia magna exposed to an aqueous preparation of the nominal concentration of 100 mg/L of the test item were not affected.

The test material concentration in the aqueous test medium was not determined due to its low water solubility (< 0.9 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.

For the test material the following nominal EC₅₀values for Daphnia magna were determined:

24 h EC₅₀      > 100 mg/L

48 h EC₅₀      > 100 mg/L

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

Conclusion

An aqueous solution of nominal 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 48 hour EC₅₀for Daphnia magna exceeded the maximum solubility of the test material in reconstituted water (< 0.9 mg/L) and, thus, could not be determined in this test.

Validity criteria fulfilled:

yes

Conclusions:

An aqueous solution of nominal 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 48 hour EC50 for Daphnia magna exceeded the maximum solubility of the test material in reconstituted water (< 0.9 mg/L) and, thus, could not be determined in this test.

Executive summary:

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 202. An aqueous solution of nominal 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 48 hour EC₅₀for Daphnia magna exceeded the maximum solubility of the test material in reconstituted water (< 0.9 mg/L) and, thus, could not be determined in this test..

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For this endpoint information from a structural similar compound, 1-Ethoxy-2,3-difluoro-4-[trans-4-(trans-4-propylcyclohexyl)-cyclohexyl]-benzene, is available. This study for this similar compound was performed according to GLP and the methods applied are fully compliant with OECD TG 202. See chapter 13 report for a more detailed justification.

Reason / purpose for cross-reference:

read-across source

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: water solubility < 0.9 mg/L

Key result

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: water solubility < 0.9 mg/L

Validity criteria fulfilled:

yes

Conclusions:

Read Across Information: (48 h) EC50 > 100 mg/L

Executive summary:

For this endpoint information from a structural similar compound is available. This study for this similar compound, 1-Ethoxy-2,3-difluoro-4-[trans-4-(trans-4-propylcyclohexyl)-cyclohexyl]-benzene, was performed according to GLP and the methods applied are fully compliant with OECD TG 202. See chapter 13 report for a more detailed justification.

Description of key information

Read Across: (48 h) EC50 > 100 mg/L (nominal)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

For this endpoint information from a structural similar compound is available. This study for this similar compound was performed according to GLP and the methods applied are fully compliant with OECD TG 202. See chapter 13 report for a more detailed justification.