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

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:

September 8, 2011 - January 9, 2012

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:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

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)

Specific details on test material used for the study:

Designation: 4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl
Batch: E011064311
Appearance: colourless solid
Released until: May 31, 2013
Purity (GC): > 99.90 %


TREATMENT OF TEST MATERIAL PRIOR TO TESTING
Before exposure of the fish, the test medium (reconstituted water and test material) was freshly prepared. 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. After 24 hours the formulation was given through a suction filter (pore size 10 - 16 µm). The filtrate was used for the study.

Analytical monitoring:

no

Remarks:

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/mL).

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Before exposure of the fish, the test medium (reconstituted water and test material) was freshly prepared. 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. After 24 hours the formulation was given through a suction filter (pore size 10 - 16 µm). The filtrate was used for the study.
- Controls: reconstituted water
- Chemical name of vehicle: OECD 203 Medium

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish (Danio rerio)
- Strain: West-Aquarium
- Source: Institute of Toxicology, Merck KGaA
- Age at study initiation (mean and range, SD):
- Length at study initiation: 2.0 ± 1.0 cm
- Weight at study initiation: Body weight per group 6.1 g (control group) and 5.6 g (test material group)


ACCLIMATION
- Acclimation period: 12 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food during acclimation:
- Feeding frequency during acclimation: During the acclimatization, until one day before the experimental part, the fish were fed with flakes (Tetra Min® diet; Tetra GmbH, Melle). Furthermore, the fish were fed with frozen cyclops, frozen artemia, or frozen mosquitolarva daily.
- Health during acclimation (any mortality observed): no mortality observed


FEEDING DURING TEST
The zebrafish were not fed during the study.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

no

Hardness:

about 267 mg/L CaCO3

Test temperature:

21 to 23°C

pH:

7.21 - 7.60

Dissolved oxygen:

74.6 - 91.5%

Salinity:

no data

Conductivity:

no data

Nominal and measured concentrations:

Nominal Concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 10L glass aquarium
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, 10L, no headspace, about 10L
- Aeration: none
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (OECD 203 Medium)
- Ca/Mg ratio: 4 : 1
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 12 hours light - 12 hours dark regime
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and Clinical Symptoms (daily)

TEST CONCENTRATIONS
- Range finding study:
- Test concentrations: 0 mg/L and 100 mg/L (nominal)
- Results used to determine the conditions for the definitive study: no mortality observed

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: > 0.0028 mg/L

Details on results:

Under the conditions of the present study, an aqueous solution of nominal 100 mg/L of 4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl revealed no aquatic toxicity in the test system.


The 96h 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
- Observations on body length and weight: none
- Other biological observations: none
- Mortality of control: none
- Other adverse effects control: none
- Abnormal responses: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: yes

Validity criteria fulfilled:

yes

Conclusions:

An aqueous solution of -Ethyl-2',3'-
difluor-4''-propyl-1,1':4',1''-terphenyl of a nominal concentration of 100 mg/L revealed no aquatic toxicity in the test system. The 96 h LC50 value could not be determined in this test, because it exceeded the maximum solubility of the test material in reconstituted water (LC50 > 100 mg/L).

Executive summary:

Objective

 

The objective of this study was to determine the acute toxicity of the test material 4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl in the zebrafish (Danio rerio).

 

Study design

 

For this purpose, 10 fish (test material group) were exposed to a saturated aqueous test material solution of nominal 100 mg/L (limit test) in an open static system for 96 hours. Further 10 fish were kept in reconstituted water as control.The fish were observed for signs of toxicity or death for 96 hours.

 

Results

 

The zebrafish exposed to an aqueous solution with a nominal concentration of 100 mg/L 4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl were not affected.

The test material concentration in the aqueous medium 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 sufficient 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 LC₅₀values for zebrafish were determined:

24 h LC₅₀      nominal > 100 mg/L

48 h LC₅₀      nominal > 100 mg/L

72 h LC₅₀      nominal > 100 mg/L

96 h LC₅₀      nominal > 100 mg/L

 

Conclusion

An aqueous solution of 4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl of a nominal concentration of 100 mg/L revealed no aquatic toxicity in the test system. The 96 h LC₅₀ value could not be determined in this test, because it exceeded the maximum solubility of the test material in reconstituted water (LC₅₀> 100 mg/L).

Description of key information

GLP compliant OECD 203:

NOEC (96 h) =100 mg/L (nominal)

LC50 (96 h) > 100 mg/L (nominal)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L