A mixture of cis- and trans-cyclohexadec-8-en-1-one

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:

2017-10-08 to 2017-10-13

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

Remarks:

GC-MS method

Details on sampling:

At the start of the exposure and at renewal (0 and 24 hours), samples of the fresh media were taken after preparation of all test item concentrations and analyzed. At renewal and at the end of the exposure (24 and 48 hours), samples of the 24-hours old media were taken directly from the test vessels and analyzed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
-A saturated solution with a nominal loading rate of 1 mg/L of the test item was prepared in duplicate three days prior to the start of the exposure (at -72 hours) and three days prior to the renewal of the test solutions (at -48 hours) in tightly closed glass flasks with a lateral outlet. The glass flask (total volume ca. 1150 mL) was filled with 1000 mL of the dilution water. The test item (1 mL) was placed by pipette onto the water surface and the bottle was closed with the screw cap. A slow stirring procedure was applied. Gentle stirring (to avoid formation of an emulsion) was carried out for 72 hours with a magnetic stirrer at room temperature. After completion of stirring, the dispersion was allowed to stand for 1 hour for separation of undissolved test item. Thereafter, the saturated solution was removed by the lateral outlet of the flask (from the approximate bottom of the glass flask). The saturated solution was checked via laser beam (Tyndall effect) for undissolved test item (formation of an emulsion). No Tyndall effect was observed in any approach. The replicates of the saturated solution were pooled and used as highest concentration level and as a stock solution for the preparation of further dilution levels by dilution with dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna STRAUS
- Age at study initiation: < 24 h
- Method of breeding: 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, with an algae cell density of > 106 cells/mL. The algae are cultured at the test facility.
- Feeding during test: no

ACCLIMATION
- Acclimation period: 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

Hardness:

Water Quality Parameters of the Dilution Water at the Start of the Exposure and at Renewal:
0 hour: 165 [mg CaCO3/L];
24 hours: 170 [mg CaCO3/L]

Test temperature:

20.8-20.9 °C

pH:

7.74-8.15

Dissolved oxygen:

9.09-8.79 mg O2/L

Salinity:

n.a.

Conductivity:

416-444 [µS/cm]

Nominal and measured concentrations:

Nominal concentrations: 1.94 - 4.27 - 9.39 - 20.7 - 45.5 - 100% of the saturated solution;
The geometric mean measured concentrations: 13.7 – 36.6 – 81.2 – 147 – 325 - 655 µg/L

Details on test conditions:

TEST SYSTEM
- Type: closed system
- Material, size, headspace, fill volume: Sealed glass flasks (4.5 (ID) x 9.5 (H) cm), fill volume = 130 mL, no headspace
- Renewal rate of test solution (frequency/flow rate): every 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

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

RANGE-FINDING STUDY
- Test concentrations: 10 and 100% of the saturated solution
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate (SIGMA-ALDRICH, batch number MKBV0900V, purity 99.0%, CAS RN 7778-50-9)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

275 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

655 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 13.7 - < 325 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: no
- Other adverse effects control: no
- Immobilisation of control: 0
- Abnormal responses: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50: 1.92 mg/L
- Valid range: 0.6 - 2.4 mg/L, acc. to AQS P 9/2 (02/2000); clone 5
0.6 - 2.1 mg/L, acc. to OECD 202 (2004); clone A

Absolute Numbers of immobile Daphnids after 24 and 48 hours of Exposure in the Definitive Test

Geometric mean measured test item concentration [µg/L]	Number of immobile Daphnids / Total number of Daphnids
	24 h					48 h
	Replicates					Replicates
	1	2	3	4	MV	1	2	3	4	MV
655	4 / 5	5 / 5	5 / 5	5 / 5	19 / 20	5 / 5	5 / 5	5 / 5	5 / 5	20 / 20
325	3 / 5	4 / 5	4 / 5	4 / 5	15 / 20	4 / 5	5 / 5	5 / 5	5 / 5	19 / 20
147	0 / 5	0 / 5	0 / 5	1 / 5	1 / 20	0 / 5	0 / 5	1 / 5	1 / 5	2 / 20
81.2	1 / 5	1 / 5	1 / 5	2 / 5	5 / 20	1 / 5	2 / 5	1 / 5	2 / 5	6 / 20
36.6	0 / 5	0 / 5	2 / 5	0 / 5	2 / 20	0 / 5	0 / 5	2 / 5	0 / 5	2 / 20
13.7	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20
Control	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20

Validity criteria fulfilled:

yes

Conclusions:

The acute immobilization effect of the test item to Daphnia magna (STRAUS) was determined and resulted in an EC50 value of 275 µg/L based on the geometric mean measured concentrations of the test item.

Executive summary:

The acute immobilization effect of the test item to Daphnia magna (STRAUS) was determined according to OECD TG 202 and GLP. The test was conducted in a closed system (sealed glass flasks) without headspace under semi-static conditions over a period of 48 hours with the undiluted saturated solution of the test item and further five dilution levels (nominal: 1.94 to 100%) prepared from the saturated solution in a geometric series with a separation factor of 2.2. 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 fresh media at the start of the exposure and at renewal (0 and 24 hours) and in old media at renewal and at the end of the test (24 and 48 hours) in all concentration levels and the control. Under the test concentration, the acute immobilization effect of the test item to Daphnia magna (STRAUS) was determined and resulted in an EC50 value of 275 µg/L based on the geometric mean measured concentrations of the test item. 

Description of key information

A study on the acute immobilization effect of the item to Daphnia magna (STRAUS) is available. The test was conducted according to OECD TG 202 and GLP in a closed system (sealed glass flasks) without headspace under semi-static conditions over a period of 48 hours with the undiluted saturated solution of the test item and further five dilution levels (nominal: 1.94 to 100%) prepared from the saturated solution in a geometric series with a separation factor of 2.2. 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 fresh media at the start of the exposure and at renewal (0 and 24 hours) and in old media at renewal and at the end of the test (24 and 48 hours) in all concentration levels and the control. Under the test concentration, the acute immobilization effect of the test item to Daphnia magna (STRAUS) was determined and resulted in an EC50 value of 275 µg/L based on the geometric mean measured concentrations of the test item. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

275 µg/L