Cyclooctane

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:

2021-12-14 to 2021-12-16

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure and at the renewal (0 and 24 hours), samples were taken after preparation of the loading levels and analyzed. At the renewal and at the end of the exposure (24 and 48 hours), samples of the 24-hours old media were taken from the test vessels.
All samples were immediately extracted and stored at room temperature. Until the start of the analysis the prepared samples were stored on an autosampler.

Vehicle:

yes

Remarks:

dilution water (Culture Medium Elendt M4)

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A saturated solution with a nominal loading rate of 100 mg test item/L was prepared at room temperature 24 ± 1 hour prior to the start of the exposure and the renewal of the test solutions. An appropriate amount of the test item was pipetted onto the surface of the dilution water. For this purpose, the density was taken into account. A slow stirring procedure was applied for 24 ± 1 hour at room temperature. After a separation phase of 1 hour at room temperature, the saturated solution was removed by siphoning from the bottom of the glass bottle and was used in the test. The saturated solution was checked via laser beam (Tyndall effect) for undissolved test item. The saturated test item solution showed no Tyndall effect. Out of the saturated solution 5 concentrations were tested in a test item solutions geometric series with a dilution factor of 1.8: 0.953 - 1.72 - 3.09 - 5.56 - 10.0 % of the saturated solution.
- Controls:
Control: Dilution water without test item incubated under the same conditions as the test groups.
Reference Test: A reference test with potassium dichromate was conducted as an acute immobilization test (acc. to AQS P 9/2 and OECD 202) in Elendt M4 medium under static conditions with a test duration of 24 hours once per quarter in order to prove the validity of the test system and test conditions at the test facility.
- Test concentration separation factor: 1.8
- Evidence of undissolved material: No.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Daphnia magna STRAUS
- Age at study initiation (mean and range, SD): less than 24 hours old; Juvenile daphnids were removed from the culture vessels at the latest 24 hours before the start of the exposure and discarded. The juveniles born within the following period were used for the test. No first brood progeny was used for the test.
- Method of breeding: In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 +/- 2 °C, 16 hours illumination; light intensity of max. 1500 lx. The daphnids are fed at least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus. The algae are cultured at the test facility.
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany; breeding at: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
- Feeding during test: The daphnids were not fed during the study.

ACCLIMATION
Acclimatization of the daphnids was not necessary, because the composition of the dilution water was equivalent to the culture medium.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

248 - 270 mg CaCO3/L

Test temperature:

19.0 – 20.0 °C

pH:

7.33 - 7.98

Dissolved oxygen:

7.40 - 9.31 mg/L

Salinity:

Not applicable

Conductivity:

612 - 627 µS/cm

Nominal and measured concentrations:

0.020 - 0.043 - 0.088 - 0.165 – 0.342 mg/L (geometric mean measured)

Details on test conditions:

TEST SYSTEM
- Test vessel: sealed glass flasks (4.5 (ID) x 9.5 (H) cm) with screw
- Type: closed
- Material, size, headspace, fill volume: approximately 130 mL, filled to the top
- Volume of solution: approximately 130 mL
- Aeration: no
- Renewal rate of test solution: The test solutions were renewed after 24 hours. For this purpose, a second set of test vessels was filled with the freshly prepared test solutions and the daphnids were transferred by pipette.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dilution water was same as Culture Medium Elendt M4. It was prepared as described in OECD 202, Annex 3 (2004).
- Culture medium different from test medium: No.
- Intervals of water quality measurement: 0, 24, 48 h

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: Diffuse light, light intensity of max. 1500 lx

EFFECT PARAMETERS MEASURED: Immobilization was determined in all groups after 24 and 48 hours. An animal was considered immobile, if it was not able to swim in the water phase within 15 seconds after gentle agitation of the test vessel. Observation of other adverse, sub-lethal effects (e.g. discoloration, abnormal behavior etc.) was done, but none occurred during the course of the study.

VEHICLE CONTROL PERFORMED: yes, vehicle was same as culture medium

RANGE-FINDING STUDY
- Test concentrations: A saturated solution with a nominal loading rate of 100 mg/L (measured: 3353-3679 µg/L in fresh media) was used. Three nominal test item concentrations of 1, 10 and 100 % of the saturated solution were prepared with dilution water.
- Results used to determine the conditions for the definitive study: Yes.

Reference substance (positive control):

yes

Remarks:

potassium dichromate, used in separate test (see "Details on test solution")

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

0.342 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

0.152 mg/L

95% CI:

0.088 - 0.273

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.16 mg/L

95% CI:

0.092 - 0.278

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.165 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.087 mg/L

95% CI:

0.051 - 0.156

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.092 mg/L

95% CI:

0.054 - 0.158

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No.
- Other biological observations: Observation of other adverse, sub-lethal effects (e.g. discoloration, abnormal behavior etc.) was done, but none occurred during the course of the study.
- Mortality of control: No.
- Other adverse effects control: No.
- Immobilisation of control: The control organisms were not immobilized and showed no other signs of disease or stress, e.g. discoloration or unusual behavior such as trapping on the surface of the water, during the 48-hours test period.
- Abnormal responses: No.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No. All tested concentration levels and the control were visually clear and colorless throughout the exposure period.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

The percentage of immobility for the reference item potassium dichromate (SIGMA-ALDRICH, batch
number BCCC1619, purity 100 %, CAS RN 7778-50-9) was determined after 24 hours in a separate test. The EC50 was 1.57 mg/L (confidence limit 1.0 - 4.0 mg/L).

Validity criteria fulfilled:

yes

Conclusions:

After 48 h test item exposure the EC50 value of 0.0921 mg/L was determined in Daphnia.

Executive summary:

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item were determined at the test facility according to OECD 202 (2004). The study was conducted under semi-static conditions over a period of 48 hours with five dilution levels of a saturated solution of 100 mg/L of the test item (nominal: 0.953 – 1.72 – 3.09 – 5.56 – 10.0 % of the saturated solution) prepared in a geometric series with a separation factor of 1.8. The geometric mean measured test item concentrations are 0.020 – 0.043 – 0.088 – 0.165 – 0.342 mg/L. The saturated solutions and the control were colorless and visually clear. Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control. The concentrations of the test item were analytically verified via GC-MS in the fresh media of all concentration levels and in the control at the start of the exposure and at the renewal (0 and 24 hours) as well as in the 24-hours old media at the renewal and at the end of the test (24 and 48 hours). The measured concentrations of the test item in the fresh media were in the range of 0.0396 to 0.417 mg/L at the start of the exposure (0 hours) and in the range of 0.0130 to 0.165 mg/L at the renewal (24 hours), without the 10 % loading rate due to 100 % mortality. The measured concentrations of the test item in the old media at the renewal and at the end of the test (24 and 48 hours) were in the range of 59 to 87 % of the initially measured values. The geometric mean measured concentrations were calculated. Procedural recovery samples (QC) were prepared on the 10 x LOQ level and treated in parallel to the test item samples. Mean recovery was 97 to 120 % and confirmed therefore the validity of the analytical method. The following effect concentrations with their respective 95 % confidence limits were determined: EC10 at 24 h was 0.152 mg/L (0.0884 – 0.273), EC10 at 48 h was 0.0869 mg/L (0.0510 – 0.156), EC50 at 24 h was 0.160 mg/L (0.0923 – 0.278), EC50 at 48 h was 0.0921 mg/L (0.0537 – 0.158), EC100 at 24 h was 0.342 mg/L and EC100 at 48 h was 0.165 mg/L. All effect concentrations are based on the geometric mean measured concentrations of the test item. The validity criteria of the test guidelines were fulfilled.

Description of key information

After 48 h test item exposure the EC50 value of 0.0921 mg/L was determined in Daphnia (reference 6.1.3-1).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.092 mg/L

Additional information

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item were determined at the test facility according to OECD 202 (2004). The study was conducted under semi-static conditions over a period of 48 hours with five dilution levels of a saturated solution of 100 mg/L of the test item (nominal: 0.953 – 1.72 – 3.09 – 5.56 – 10.0 % of the saturated solution) prepared in a geometric series with a separation factor of 1.8. The geometric mean measured test item concentrations are 0.020 – 0.043 – 0.088 – 0.165 – 0.342 mg/L. The saturated solutions and the control were colorless and visually clear. Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control. The concentrations of the test item were analytically verified via GC-MS in the fresh media of all concentration levels and in the control at the start of the exposure and at the renewal (0 and 24 hours) as well as in the 24-hours old media at the renewal and at the end of the test (24 and 48 hours). The measured concentrations of the test item in the fresh media were in the range of 0.0396 to 0.417 mg/L at the start of the exposure (0 hours) and in the range of 0.0130 to 0.165 mg/L at the renewal (24 hours), without the 10 % loading rate due to 100 % mortality. The measured concentrations of the test item in the old media at the renewal and at the end of the test (24 and 48 hours) were in the range of 59 to 87 % of the initially measured values. The geometric mean measured concentrations were calculated. Procedural recovery samples (QC) were prepared on the 10 x LOQ level and treated in parallel to the test item samples. Mean recovery was 97 to 120 % and confirmed therefore the validity of the analytical method. The following effect concentrations with their respective 95 % confidence limits were determined: EC10 at 24 h was 0.152 mg/L (0.0884 – 0.273), EC10 at 48 h was 0.0869 mg/L (0.0510 – 0.156), EC50 at 24 h was 0.160 mg/L (0.0923 – 0.278), EC50 at 48 h was 0.0921 mg/L (0.0537 – 0.158), EC100 at 24 h was 0.342 mg/L and EC100 at 48 h was 0.165 mg/L. All effect concentrations are based on the geometric mean measured concentrations of the test item. The validity criteria of the test guidelines were fulfilled.