Levomenol

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:

2017-09-05 to 2017-10-05

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- CAS no.: 23089-26-1
- Batch no.: K80953370
- Purity: 97% (a/a) (GC)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Samples of each test medium concentration were taken directly after preparation and after 48 hours. One replicate was used for analysis.
- Sample storage conditions before analysis: Stored in a freezer at =>20 °C. At the day of analysis, the frozen samples were thrawed at RT.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A test solution with 100 mg/L was freshly prepared. For that purpose, the test item was weighed in a calibrated flask and vehicle (reconstituted water) was added. The preparation was stirred with a magnetic stirrer for 24 hours. Than the formulation was given into a separating funnel for 1 hour. The middle fraction in the separating funnel was used for the preparation of the different test item concentrations.
- Controls: Negative control, positive control with the reference item potassium dichromate
- Name of vehicle: Reconstituted water (as cited in the study)
- Evidence of undissolved material: No

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Daphnia magna Straus
- Source: Originally obtained from IBACON GmbH (Roßdorf, Germany); clone is bred in the laboratories of Merck KGaA
- Age of parental stock: Less than 24 hours old
- Feeding during test: No

CULTURE CONDITIONS: similar to test conditions
- Container: 100 mL glass vessels containing approximately 60 mL reconstituted water (ELENDT M4 medium)
- Water temperature: 20 +- 2 °C
- Light-cycle: 16 h light : 8 h darkness
- Feeding: Only during culturing period; ad libitium with unicellar green algae Pseudokirchneriella subcapitata three times per week
METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS: Parental daphnids are used for the reproduction until they are about 6 weeks old. Thereafter, they are replaced by neonates.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

236 mg CaCO3/L

Test temperature:

20.6 to 20.9 °C

pH:

7.86

Dissolved oxygen:

8.64 mg/L

Salinity:

Not applicable

Conductivity:

711 µS/cm

Nominal and measured concentrations:

- Nominal: 0.0 (control), 5.0, 9.0, 16.2, 29.2 and 52.5 mg/L
- Measured:
fresh medium: old medium, after 48 hours:

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes
- Type: Open
- Material, size, headspace, fill volume: Glass, 20 mL nominal volume, fill volume 20 mL
- Aeration: Test perfomed in air conditioned room, no air bubbling
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 8 h darkness
- Light intensity: 601 Lux and 598 Lux prior to ans at the end of the exposure period, respectively.
- Temperature: 20.6 to 20.9 °C

EFFECT PARAMETERS MEASURED: Mobility after 24 and 48 hours


RANGE-FINDING STUDY
- Test concentrations: = 0 (control), 1, 5, 10, 25, 50, 100 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval: 2.9 - 4.2 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3.5 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval: 2.9 - 4.2 mg/L

Details on results:

In the control, not daphnids were immobilized. The dissolved oxygen concentration at the end of the exposure period was => 3 mg/L. Thus, the validity criteria were fulfilled.

Results with reference substance (positive control):

EC50 (48h): 0.74 mg/L (95% confidece interval: 0.66 - 0.82 mg/L)

Reported statistics and error estimates:

Estimation of ECx values according to Lichfield and Wilcoxon.

Nominal test item concentration [mg/L]	Analytical results
	0h		48h
	[mg/L]	Recovery from nom. [%]	[mg/L]	Recovery from nom. [%]	Recovery from 0h conc. [%]
0.0	<LOD	-	<LOD	-	-
5.0	0.844	16.9	0.763	15.3	90.4
9.0	1.584	17.6	1.472	16.4	92.9
16.2	3.05	18.8	2.684	16.6	88
29.2	5.231	17.9	5.028	17.2	96.1
52.5	9.501	18.1	8.818	16.8	92.8

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study, the test item showed a 48-h EC50 of 2.2 mg/L.

Executive summary:

To determine the effect of the test item on the mobility to Daphnia magna, an acute Immobilisation Test according to OECD Guideline 202 and EU Method C.2 was carried out in compliance with GLP principles. Juvenile daphnids (less than 24 hours old) were exposed to different test item concentrations of nominal 0.0 (blank control, only with ELENDT M4 Medium), 5.0, 9.0, 16.2, 29.2 and 52.5 mg/L in an open static system. 20 daphnids, devided into four replicates, each five animals were used per test item group and the control group. The daphnids were observed for immobilization after 24 and 48 hours of exposure. Samples of the test and control medium were taken directly after preparation and at the end of exposure (48 h) and stored at =< -20 °C until further analysis of the test item concentration via HPLC with UV detection. The measured concentrations were between 15.3% and 18.8% of the nominal concentrations. As the recoveries of the test item in the aqueous solutions were >80% of the initial concentrations during the study, the 24-h and 48-h EC50 values were calculated with the initial measured concentrations. In result, the test item showed a 48-h EC50 of 2.2 mg/L. All validity criteria of the guidelines were fulfilled.

Description of key information

The 48-h EC50 of the test item was determined to be 2.2 mg/L (based on initial measured concentrations).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.2 mg/L

Additional information

To determine the effect of the test item on the mobility to Daphnia magna, an acute Immobilisation Test according to OECD Guideline 202 and EU Method C.2 was carried out in compliance with GLP principles. Juvenile daphnids (less than 24 hours old) were exposed to different test item concentrations of nominal 0.0 (blank control, only with ELENDT M4 Medium), 5.0, 9.0, 16.2, 29.2 and 52.5 mg/L in an open static system. 20 daphnids, devided into four replicates, each five animals were used per test item group and the control group. The daphnids were observed for immobilization after 24 and 48 hours of exposure. Samples of the test and control medium were taken directly after preparation and at the end of exposure (48 h) and stored at =< -20 °C until further analysis of the test item concentration via HPLC with UV detection. The measured concentrations were between 15.3% and 18.8% of the nominal concentrations. As the recoveries of the test item in the aqueous solutions were >80% of the initial concentrations during the study, the 24-h and 48-h EC50 values were calculated with the initial measured concentrations. In result, the test item showed a 48-h EC50 of 2.2 mg/L. All validity criteria of the guidelines were fulfilled (reference 6.1.3 -1).