1-fluoro-3-(trans-4-propylcyclohexyl)benzene

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 MAR 2015 - 22 APR 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

adopted on March 23, 2006; Annex 5 corrected: July 28, 2011

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Hess. Ministerium für Umwelt, Energie, Landwirtschaft und Verbraucherschutz

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Reconstituted water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test medium (reconstituted water and test item) was prepared freshly. Therefore, the calibrated flask with test medium were stirred with a magnetic stirrer for 24 hours. Then the formulation was given into a separating funnel for 1 hour. The middle layer was centrifuged at 4100g for further 2 hours. The middle layer after centrifugation was used for the study.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Unicellular green algae
- Strain: strain 86.81 SAG
- Source (laboratory, culture collection): Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen, Germany
- Method of cultivation: Prior to start the study, the algae were grown in reconstituted water as preculture and the growth rate was determined.

ACCLIMATION
- Acclimation period: yes, 3 days
- Culturing media and conditions (same as test or not): yes
- Any deformed or abnormal cells observed: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

for details see composition of reconstituted water "details on test conditions"

Test temperature:

22.4 - 23.2°C

pH:

7.88 - 7.6 in control group

Dissolved oxygen:

saturated

Nominal and measured concentrations:

0 mg/L, 100 mg/L nominal

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, 300 mL, air permeable steristoppers
- Aeration: continuously shaken
- Initial cells density: 10,000 cells per mL
- Control end cells density: 1,112,160
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The test medium (reconstituted water and test material) was freshly prepared.

- Particulate matter: none
Details on composition of the reconstituted water:

Nutrient mg/L
NH4CI 15.0
MgCl2 * 6H2O 12.0
CaCl2 * 2H2O 18.0
MgSO4 * 7H2O 15.0
KH2PO4 1.60
FeCl3 * 6H2O 0.0640
Na2EDTA * 2H2O 0.100
H3BO3 0.185
MnCl2 * 4H2O 0.415
ZnCl2 0.00300
CoCI2 * 6H2O 0.00150
CuCl2 * 2H2O 0.00001
Na2MoO4 * 2H2O 0.00700
NaHCO3 50.0

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: continously
- Light intensity and quality: 7160 Lux ± 5.4% and 6881 Lux ± 4.4% at the end of the study (between 4440 and 8880 Lux and within ± 15% from the average)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: electronic particle counter (observation interval 24 h)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: none
- Justification for using less concentrations than requested by guideline: limit test due to low water solubility
- Range finding study: yes
- Test concentrations: 0 and 100 mg/L nominal

Reference substance (positive control):

yes

Remarks:

potassium dichromate (Study No. 14-DA479-N0, 2015)

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Remarks on result:

other: EC10(72h)>9.74 µg/L

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: EC50(72h)>9.74 µg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: EC10(72h)>9.74 µg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: EC50(72h)>9.74 µg/L

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no
- Effect concentrations exceeding solubility of substance in test medium: yes

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50: 0.71 (0.67-0.74) mg/L
- Other: Under the given experimental conditions, the test item potassium dichromate showed 72h EC values which are within the recommended range (Biomass integral EC50 0.20 - 0.75 mg/L and Growth rate EC50 0.60 - 1.03 mg/L).

Validity of the Test

In the control group the biomass increased by a factor of 111.0 over 72 hours. The validity criterion of increase of biomass by at least a factor of 16 within three days was fulfilled. The mean coefficient of variation of the daily growth rates in the control group (section-by-section growth rates) during 72 hours was 17.8%. According to the OECD test Guideline, the mean coefficient of variation must not be higher than 35%. Thus, the validity criterion was fulfilled. The coefficient of variation of the average specific growth rates in the replicates of the control group after 72 hours was 1.9%. According to the OECD test Guideline, the coefficient of variation must not be higher than 7%. Thus, the validity criterion was fulfilled.

Validity criteria fulfilled:

yes

Conclusions:

An aqueous preparation of 100 mg/L (nominal) of the test material revealed no toxic effect in the test system. Analytically, the 72 hours EC50 to Desmodesmus subspicatus could not be determined; it exceeded the maximum solubility of the test material in reconstituted water.

Executive summary:

The registered substance was tested for toxicity to algae in an acute growth inhibition test according to OECD Guideline 201 following GLP.

Purpose

The objective of this study was to evaluate the influence of the test item on the growth and growth rate of the green algae species Desmodesmus subspicatus.

Study Design

The study design included one control group and one test item group with six replicates, each containing 100 mL reconstituted water or test medium and 10,000 cells/mL at the start of the experimental phase.

The study was performed as a limit test in an open static test system. The algae were exposed to a filtrate of nominal 100 mg/L.

The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test item group and control group.

Results

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 (9.74 µg/L), the compound cannot be detected with standard analytical methods and 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.

An aqueous preparation of a nominal concentration of 100 mg/L of the test item revealed no toxic effect in Desmodesmus subspicatus.

The following EC values (Growth rate and Yield) were determined:

Parameter (0-72h)	Growth rate	Yield
EC10 95% confidence interval	> 9.74 µg/L (nominal > 100 mg/L) n.d.	> 9.74 µg/L (nominal > 100 mg/L) n.d.
EC20 95% confidence interval	> 9.74 µg/L (nominal > 100 mg/L) n.d.	> 9.74 µg/L (nominal > 100 mg/L) n.d.
EC50 95% confidence interval	> 9.74 µg/L (nominal > 100 mg/L) n.d.	> 9.74 µg/L (nominal > 100 mg/L) n.d.

n.d. could not be determined

Conclusion

Under the conditions of the present study, an aqueous solution of 100 mg/L of the test item in an open static system revealed no aquatic toxicity.

The EC₅₀ (0-72h) for Growth rate and Yield were > 9.74 µg/L (nominal > 100 mg/L) and, thus, could not be determined in this study.

Description of key information

Key, growth rate inhibition, D. subspicatus, limit test, OECD 201, GLP: EC₅₀(72h) > 100 mg/L (nominal), EC₁₀(72h) > 100 mg/L (nominal)

Additional information

Growth inhibition, OECD 201

Purpose

The objective of this study was to evaluate the influence of the test item on the growth and growth rate of the green algae species Desmodesmus subspicatus.

Study Design

The study design included one control group and one test item group with six replicates, each containing 100 mL reconstituted water or test medium and 10,000 cells/mL at the start of the experimental phase.

The study was performed as a limit test in an open static test system. The algae were exposed to a filtrate of nominal 100 mg/L.

The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test item group and control group.

Results

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 (9.74 µg/L), the compound cannot be detected with standard analytical methods and 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.

An aqueous preparation of a nominal concentration of 100 mg/L of the test item revealed no toxic effect in Desmodesmus subspicatus.

The following EC values (Growth rate and Yield) were determined:

Parameter (0-72h)	Growth rate	Yield
EC10 95% confidence interval	> 9.74 µg/L (nominal > 100 mg/L) n.d.	> 9.74 µg/L (nominal > 100 mg/L) n.d.
EC20 95% confidence interval	> 9.74 µg/L (nominal > 100 mg/L) n.d.	> 9.74 µg/L (nominal > 100 mg/L) n.d.
EC50 95% confidence interval	> 9.74 µg/L (nominal > 100 mg/L) n.d.	> 9.74 µg/L (nominal > 100 mg/L) n.d.

n.d. could not be determined

Conclusion

Under the conditions of the present study, an aqueous solution of 100 mg/L of the test item in an open static system revealed no aquatic toxicity.

The EC₅₀(0-72h) for Growth rate and Yield were > 9.74 µg/L (nominal > 100 mg/L) and, thus, could not be determined in this study.