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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
Study period:
December 12, 2013 - March 27, 2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014
Report Date:
2014

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
2004
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Version / remarks:
Council Regulation (EC) No. 440/2008 laying down test methods pursuant to Regulation (EC) No. 1907/2006 of the European Parliament and the council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Specific details on test material used for the study:
TREATMENT OF TEST MATERIAL PRIOR TO TESTING
The test medium (reconstituted water and test item) was prepared freshly. Therefore, the calibrated flask with test medium was treated in an ultrasonic device for 1 hour. Subsequently, the preparation was stirred with a magnetic stirrer for further 23 hours. Afterwards, the formulation was passed through a membrane filter with a pore size of 0.2 µm. The filtrate was used for the study.

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
The test item concentration in the reconstituted water was not quantified at the start and the end of this study due to the low water solubility.
The compound cannot be detected with standard analytical methods, due to the low water solubility (0.00022 mg/L). 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.

Test solutions

Vehicle:
yes
Details on test solutions:
Preparation of the Test Item:
The test medium (reconstituted water and test item) was prepared freshly. Therefore, the calibrated flask with test medium was treated in an ultrasonic device for 1 hour. Subsequently, the preparation was stirred with a magnetic stirrer for further 23 hours. Afterwards, the formulation was passed through a membrane filter with a pore size of 0.2 µm. The filtrate was used for the study.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Species: Daphnia magna Straus
Culture conditions: The Daphnia magna were kept in reconstituted water in glass-vessels. The study was located in an air-conditioned room. Lighting was controlled by a timer to provide a 16 hours light - 8 hours dark regime.
Temperature and humidity in the experimental room was measured using ausing MCPS (Multi Channel Process System).
During the study, the daphnids were kept in glass test tubes as test vessels containing at least 20 ml either reconstituted water (control group) or test media (test item group). They were not fed, and the control medium and test medium were not aerated during the experimental phase. The vessels were placed on a dark surface in a plastic box with a lid.
Feeding: The parental daphnids are fed ad libitum with unicellular green algae Desmodesmus subspicatus
Age: Offspring less than 24 hours old were used for the study.
Acclimation period: same as test

Feeding during test: None

Study design

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

Test conditions

Test temperature:
20.8 - 21.4°C
pH:
7.44 - 7.73
Dissolved oxygen:
7.26 - 8.41 mg/L
Nominal and measured concentrations:
Nominal 100 mg/L
Details on test conditions:
EXPOSURE:
). During the study, the daphnids were kept in glass test tubes as test vessels containing at least 20 ml either reconstituted water (control group) or test media (test item group). They were not fed, and the control medium and test medium were not aerated during the experimental phase. The vessels were placed on a dark surface in a plastic box with a lid.

The test was performed as a static test in open vessels.

The duration of exposure was 48 hours. During the exposure period, the mobility of the daphnids was assessed daily, i.e. after 24 and 48 hours.

NO. OF DAPHNIDS:
Control Group: 20 daphnids
100 mg/L: 20 daphnids

CONCENTRATION(S)
In a pre-test no immobilization was observed at a concentration of 100 mg/L under open static conditions. Therefore, the solution of a nominal test item concentration of 100 mg/L was tested in the present study.

For the control, reconstituted water (ELENDT M4 medium) was used.

VEHICLE
Reconstituted water (ELENDT M4 medium) was used as vehicle.

Macro nutrients (mg/L)
CaCI2 •2H20 293.80
MgSO4•7H20 123.30
NaHCO3 64.80
KCI 5.80
Na2SiO3•9H20 10.00
NaNO3 0.27
KH2PO4 0.14
K2HPO4 0.18

Trace elements (mg/L)
B 0.5000
Fe 0.2000
Mn 0.1000
Li, Rb and Sr 0.0500
Mo 0.0250
Br 0.0125
Cu and Zn 0.0063
Co and I 0.0025
Se 0.0010
V 0.0003

Macro nutrients (mg/L)
Na2EDTA • 2H20 2.50

Vitamins (µg/L):
Thiamine 75.00
B12 1.00
Biotin 0.75

- pH: 7.72
- O2-Concentration: 8.41 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: 48 h


OTHER TEST CONDITIONS
- Photoperiod: 16h light / 8h dark

References:

ELENDT, B.-P. Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus.
Protoplasma 154, 25-33, 1990
Reference substance (positive control):
no
Remarks:
No positive control used in this study. The accuracy and reliability of the test method is demonstrated periodically as recommended by guidelines with potassium dichromate.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
24 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: >0.00022 mg/L
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: >0.00022 mg/L
Details on results:
The 48 hour EC50 for the test material to Daphnia magna could not be quantified due to the absence of toxicity at the highest test concentration achievable in water. An aqueous filtrate of 0.1 g/L nominally revealed no aquatic toxicity in the test system.


The 48h EC50 exceeded the water solubility of 0.00022 mg/L (nominal >100 mg/L) and, thus, could not be determined in this study.

- Behavioural abnormalities: no
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
Results with reference substance (positive control):
Study design:
The study was performed with the test item Art. 104864 (Potassium dichromate) as positive control to check the sensitivity of the test system as recommended by guidelines.
Groups of Daphnia magna were exposed to different concentrations of the test item in reconstituted water for 48 hours. The daphnids were observed for immobilization, 24 and 48 hours after placing in the test medium. The study comprised of four test vessels per concentration containing five daphnids, i.e., 20 daphnids per concentration. Additionally, one control group (20 daphnids) was used.
Test item concentrations of 0.31, 0.46, 0.69, 1.02, and 1.52 mg/L were used in this study.

Results:
Art. 104864 (Potassium dichromate) is the recommended positive control substance and thus no analysis was carried out.
The EC50 values with the 95% confidence intervals:
24h EC50 1.200 mg/L (1.049 – 1.437 mg/L)
48h EC50 0.819 mg/L (0.721 – 0.931 mg/L)

Conclusion:
Under the given experimental conditions, the test item Art. 104864 (Potassium dichromate) showed a 24h EC50 value which was within the range of the published data of 0.6 to 1.7 mg/L (Council Regulation (EC) No. 440/2008) and 0.6 to 2.1 mg/L (OECD Guideline No. 202).

Any other information on results incl. tables

Study Design

The objective of this study was to evaluate the influence of the test item on the immobilization of Daphnia magna. For this purpose, juvenile daphnids were exposed to a nominal test item concentration of 100 mg/L (limit test) over 48 hours, in an open static system. The daphnids were observed for immobilization 24 and 48 hours after placing in the aqueous test item solution. The study comprised of one test item group with four test vessels containing five daphnids each, i.e. 20 daphnids in total. Additionally, one control group (20 daphnids) was used.

Results

The test item concentration in the reconstituted water was not quantified at the start and the end of this study due to the low water solubility (0.00022 mg/L). Because of the low water solubility, the compound cannot be detected with standard analytical methods. 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.

Daphnids exposed to an aqueous preparation of a nominal concentration of 100 mg/L of the test item were not affected.

The following EC50values for daphnids were determined:

24h EC50       >0.00022 mg/L (nominal >100 mg/L)

48h EC50       >0.00022 mg/L (nominal >100 mg/L)

Conclusion

The test item, dissolved in reconstituted water, was tested in an open static test system. Under the conditions of the present study, an aqueous solution of nominal 100 mg/L of
the test item revealed no aquatic toxicity in the test system.
The 48h EC50was >0.00022 mg/L (nominal >100 mg/L) and, thus, could not be determined in this study.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 48 hour EC50 for the test material to Daphnia magna could not be quantified due to the absence of toxicity at the highest test concentration achievable in water. An aqueous filtrate of 0.1 g/L nominally revealed no aquatic toxicity in the test system.
Executive summary:

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 202. The 48 hour EC50 for the test material to Daphnia magna could not be quantified due to the absence of toxicity at the highest test concentration achievable in water. An aqueous filtrate of 0.1 g/L nominally revealed no aquatic toxicity in the test system.