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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GPL guideline study without restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Storage conditions: Room temperature
- Physical state/ color: Solid /white

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:
The test substance is poorly water soluble, estimated water solubility <0.01 μg/L (EPISUITE), therefore a saturated solution was prepared as water soluble fraction (WSF) of a loading concentration of 100 mg/L following general guidance provided in OECD 23. The saturated test solution was prepared by directly adding test substance to test medium
according to the loading concentration described in the table below and stirring for about 2 days.
At the end of the stirring period undissolved test substance was visible, most of it on the water surface and attached to the flask. To avoid any physical effects of the undissolved fraction of the test substance on the test organisms and to insure the testing of only the aqueous dissolved fraction of test substance, undissolved material was removed prior to exposure as recommended in OECD 23 to obtain the water-soluble fraction (WSF). Undissolved test substance was removed by filtration with a membrane filter (pore width 0.2 μm). The first 50- 100 mL of filtered solution was discarded (used to condition the filter). The filtrates appeared colorless and clear. The exposure was started after separation of the undissolved material. The control was treated in the same way.
The test solution was filtered to remove undissolved substance. In a preliminary investigation the undissolved substance floated on the solution surface and could not be separated with centrifugation.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Source: The clone of Daphnia magna STRAUS 1820
used was supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978. From this date on this clone was cultured and bred continuously in the Laboratory of Ecotoxicology of the Experimental Toxicology and Ecology of BASF SE in Ludwigshafen.
- Age at study initiation (mean and range, SD): < 24 hours (at least 3rd brood progeny)
- Feeding during test: no

ACCLIMATION
- Acclimation period: Daphnia brood stock are kept in mass cultures consisting of approx. 20 – 30 parthenogenetically reproducing females for a maximum of 4 weeks
- Acclimation conditions (same as test or not): identical conditions including test media (Elendt M4), water quality, and temperature (20 ±1°C).
- Type and amount of food: live unicellular algae (Desmodesmus subspicatus), cultured continuously at the test facility.

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:
After approximately 14 days the adults have produced at least 3 broods and the young can be used in tests. Offspring are removed from the mass cultures at least once daily during the normal work week to ensure that young daphnia are <24-h old (first instar) at start of the exposure. Only young from healthy cultures without signs of stress are used for testing.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
2.42 mmol/L
Test temperature:
19.6 – 20.2 °C (continuous monitoring)
pH:
8.0
Dissolved oxygen:
5.2-9.1 mg/L
low dissolved oxygen concentrations were due to a degassing of the test solution during filtration.
Conductivity:
591 μS/cm
Nominal and measured concentrations:
0 (control), 100 mg/L as loading concentration based on test substance mass
Details on test conditions:
TEST SYSTEM
- Test vessel: Glass beakers (nominal volume 100 mL)
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: 50 mL
- Aeration: none
- 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: 16:8 light:dark
- Light intensity: 159-691 lux at a wave length of 400 -750 nm


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: A synthetic fresh water (Elendt M4) is used as media for culture and test purposes. For the composition of this M4 medium see OECD 202. To assure optimal dissolved oxygen levels, the M4 medium is aerated for approximately 24 hours prior to use.
- Total hardness: 2.20 – 3.20 mmol/L
- Acid capacity up to pH 4.3: 0.80 – 1.00 mmol/L
- Molar ratio Ca:Mg: about 4 : 1
- pH value: 7.5 – 8.5
- Total organic carbon: <2 mg/L
- Conductivity: 550 - 650 μS/cm


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobilization, abnormal behaviour/appearance : after 0, 24 and 48 hours

OTHER PARAMETERS:
- continuously: temperature
- daily: appearance of the test solutions and dissolution behavior
- after aeration and prior to use in the test: chemical and physical parameters
- start and end of exposure: dissolved oxygen and pH, TOC
RANGE FINDING TEST:
In a preliminary test (experimental conduct in accordance with GLP, without a GLP status) a concentration of 100 mg/L caused no immobilisation or symptoms after 48 hours.
Reference substance (positive control):
yes
Remarks:
sodium chloride

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: based on loading concentration used to prepare a saturatred solution
Details on results:
The test substance had no observable acute effect on Daphnia magna up to its saturation limit in test media and under test conditions.

This test was fully compliant with all the following validity criteria required by the corresponding test guidelines and is considered valid: ≤10% immobilisation in the control, O2 concentration ≥3 mg/L in control and test vessels
Results with reference substance (positive control):
The EC50(48h): 5.08 g/L (experiment date: 10 Oct 2017, project number: 50E0789/12E060). This result is within the range of 3.88 – 7.22 g/L (Santos M.A.P.F., et al. (2007), Sensitivity of Four Test Organisms (Chironomus xanthus, Daphnia magna, Hydra attenuata and Pseudokirchneriella subcapitata) to NaCl: an Alternative Reference Toxicant, J. Braz. Soc. Ecotoxicol., v. 2, n. 3, 229-236) and indicates that the culture of Daphnia magna used in this study is responding normally to toxic stress.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes