Registration Dossier

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:
2018-07-17 - 2018-07-19 (experimental phase)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
under GLP

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
OECD Guideline for Testing of Chemicals No. 202, adopted 13. Apr. 2004:
”Daphnia sp., Acute Immobilisation Test“
Deviations:
yes
Remarks:
but not affecting the integrity or validity of the study
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Version / remarks:
Commission Regulation (EC) No. 440/2008, Method C.2. “Daphnia sp. Acute Immobilisation Test”, adopted 30. May 2008
Deviations:
yes
Remarks:
but not affecting the integrity or validity of the study
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
The test item was stored in a closed vessel at room temperature (20 ± 5°C).

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0, 200 mg/L test item
- Sample storage conditions before analysis: no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution containing 200.6 mg/L test item in dilution water (= 100.3 mg/L dry weight test item) was prepared and used for the test.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water fela
- Strain/clone: Daphnia magna STRAUS Berlin
- Source: Umweltbundesamt Berlin, In-house breeding since 27. September 2007
Daphnia magna is bred in the laboratory throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identical. The husbandry is performed similar to the method described in the OECD guideline.
Vessels: preserving glasses, nominal volume 2 L
Medium: M4-Medium (recipe of ELENDT)
Food: green algae (Desmodesmus subspicatus)
Medium renewal: twice a week
Photo period: 16/8 hours, using neon tubes
Temperature: 20 ± 2 °C

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:
21 hours 10 minutes before the start of the test, the adult animals were separated from the young. 40 minutes before test start, the adults were caught with the help of a glass tube, and the newborn Daphnia, aged between 0 and 20.5 hours, were sieved from the medium and immediately placed into a beaker containing dilution water. After the settling-in period, animals which showed no apparent damage were used for the test.
Switching from M4-medium (husbandry) to Dilution water (test) has been shown not to cause any detrimental effects for test Daphnia.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
none

Test conditions

Hardness:
Resulting hardness in mmol/L: 2.502
Resulting hardness in mg CaCO3/L: 250
Test temperature:
22.2 – 23.4°C
pH:
7.9 - 8.0
Dissolved oxygen:
8.5 - 8.6 mg/L
Nominal and measured concentrations:
Nominal: 0, 200 mg/L (test item; = 0, 100 mg/L dry weight)
Measured, t=0h: < LOD/LOQ, 188.56 mg/l (test item; = --, 94.28 mg/L dry weight)
Measured, t=48h: < LOD/LOQ, 209.08 mg/l (test item; = --, 104.54 mg/L dry weight)
Details on test conditions:
TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass beakers, nominal volume 50 mL, tall shape, fill volume 20 ± 5 mL test solution
- Aeration: After preparation, the dilution water was aerated.
- Renewal rate of test solution (frequency/flow rate): 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 hours
- Light intensity: neon tubes

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mobility: at t=24h and 48h
pH, O2: at t=0h, 48h

VEHICLE CONTROL PERFORMED: medium control

RANGE-FINDING STUDY
None of the exposed daphnia was immobilised at the end of the test (tested concentrations 1 / 10 / 100 / 200 mg/L wet weight of test item)
Reference substance (positive control):
yes
Remarks:
Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study.

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
>= 200 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: none stated
- Mortality of control: none
- Other adverse effects control: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: none
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: 24h-EC50
- Limit test: no
- Dose-response test: yes
- ECx: The 24h-EC50 value was determined as 1.9 mg/L. The value was within the requested range for the 24h-EC50 between 0.6 - 2.1 mg/L of potassium dichromate K2Cr2O7 as specified in the OECD guideline. Since the fits showed sufficient statistical correspondence of the data with the dose-response-equation, this reference study can be considered valid.
Reported statistics and error estimates:
As no toxicity was observed, no statistical evaluation was conducted.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The study was conducted under GLP according to OECD guideline 202 and EU method C.2 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation or deviations from the guidelines, the validity criteria were met. Hence, the results can be considered as reliable to assess the toxicity of the test item resp. the registered substance towards daphnids.
The study was performed as a limit test using a nominal concentration at 200 mg/L (= 100 mg/L dry weight test item). For the test concentration and the blank control, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.
None of the animals was immobilised in the blank control and in the tested concentration.
The concentration of the solid constituent determined at the start of the test was 94.28 % of the nominal concentration. At the end of the test the determined concentration was 104.54 % of the nominal concentration. Therefore, the determination of the biological results was based on the nominal concentration.
None of the treated animals was immobilized. Hence, the EC50 was determined as > 200 mg/L (test item) resp. > 100 mg/L (solid constituent).
Based on the obtained results, the registered substance does not need to be classified as toxic to the environment, neither acutely nor chronic, according to the Regulation (EC) No. 1272/2008.
Executive summary:

The study was conducted under GLP according to OECD guideline 202 and EU method C.2 on the registered substance itself. One valid experiment was performed.

The study was performed as a limit test using a nominal concentration at 200 mg/L (= 100 mg/L dry weight test item). For the test concentration and the blank control, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.

None of the animals was immobilised in the blank control and in the tested concentration.

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

At the beginning and at the end of the test, the content of the test item in the test solution was determined using HPLC-UV-determination. The concentration determined at the start of the test was 94.28 % of the nominal concentration. At the end of the test the determined concentration was 104.54 % of the nominal concentration. Therefore, the determination of the biological results was based on the nominal concentration.

The following results were determined for the test item 2-Butyne-1,4-diol, reaction products with 1,2-oxathiolane 2,2-dioxide and sodium hydroxide (HBOPS-Na) (species: Daphnia magna).

48h-NOEC ≥ 200 mg/L (≥ 100 mg/L dry weight test item)
48h-LOEC > 200 mg/L (> 100 mg/L dry weight test item)
24h-EC50 > 200 mg/L (> 100 mg/L dry weight test item)
48h-EC50 > 200 mg/L (> 100 mg/L dry weight test item)