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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:
11 October 2017 to 15 January 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

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
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Test material form:
liquid
Details on test material:
UVCB
Specific details on test material used for the study:
CEDRENE WASHED
Batch No. : SH00085512
Purity : Conform to Chromatogram (UVCB)
Expiry Date : 09 July 2018

The test item is a multi-component complex mixture isolated from a natural source and is, consequently, defined as an UVCB.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
At the start of the exposure and at renewal (0 and 24 hours), samples were taken after preparation of the WAF 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.

Test solutions

Vehicle:
no
Details on test solutions:
In view of the difficulties associated with the evaluation of aquatic toxicity of poorly water soluble test items, a modification of the standard method for the preparation of aqueous media was performed. An approach endorsed by several important regulatory authorities in the EU and elsewhere (ECETOC 1996 and OECD 2000), is to expose the organisms to a Water Accommodated Fraction (WAF) of the test item in cases where the test item is a complex mixture / UVCB substance and is poorly soluble in water and in the permitted solvents. Using this approach, aqueous media were prepared by mixing the test item with water for a prolonged period sufficient to ensure equilibration between the test item and the water phase. At the completion of mixing and following a settlement period, the test item phase was separated by siphon and the test organisms exposed to the aqueous phase, the WAF (which contains the dissolved fraction). Exposure is expressed in terms of the original nominal concentration of the test item in water at the start of the mixing period (loading rate) irrespective of the actual concentration of the test item in the WAF. This preparation was repeated for the renewal of the test solutions after 24 hours.

One water accommodated fraction (WAF) was prepared with a nominal loading of the test item of 100 mg/L.
The water accommodated fraction was prepared in a glass flask with a lateral outlet, which was filled up to the top with the dilution water (approximately 1150 mL). 123.1 pL of the test item (corresponding to 100 mg, when relative density of the test item of 0.9342 (D20/20) was taken into account) was placed by pipette onto the surface of the dilution water. A slow stirring procedure was applied. Gentle stirring (to avoid formation of an emulsion) was carried out with a magnetic stirrer at room temperature for 24 ± 1 hours. After completion of stirring, the dispersion was allowed to stand for at least 4 hours for separation of undissolved test item. Thereafter, the WAF was removed by the lateral outlet of the flask (from the approximate bottom of the glass flask). The resulting water accommodated fraction (WAF) was used in a limit test.
The WAF was checked via laser beam (Tyndall effect) for undissolved test item (formation of an emulsion). No Tyndall effect was observed.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Test system
Daphnia magna STRAUS (Clone 5)

Reason for the selection of the test system
Daphnia magna is the preferred species in accordance with the test guidelines and is bred at the test facility.

Origin
Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany

Breeder
Noack Laboratorien GmbH,
Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany

Culture
In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 + 2 °C, in an incubator, 16 hours illumination, light intensity of max. 1500 lx

Culture medium
Elendt M4, according to OECD 202, Annex 3 (2004), modified to a total hardness of 160 to 180 mg CaCOs/L, is used. The composition of the culture medium is presented in Table 2.

Feeding of the culture stocks
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 > 106cells/mL. The algae are cultured at the test facility.

Origin of the food algae
Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18, 37073 Göttingen, Germany

20 daphnids, divided into 4 replicates, each with 5 daphnids, were used per WAF and control.
Daphnids were not fed during the study.

Study design

Test type:
semi-static
Water media type:
freshwater
Remarks:
Elendt M4 Medium
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
166 - 175 mg CaCO3/L
Test temperature:
20.7 °C
pH:
7.56-7.65 at 24 hours and 7.50-7.63 at 48 hours
Dissolved oxygen:
8.32-8.96 mg/L at 24 hours and 8.64-8.97 mg/L at 48 hours
Nominal and measured concentrations:
One WAF was prepared with a nominal loading of the test item of 100mg/L.
Reference substance (positive control):
yes
Remarks:
Potassium Dichromate (Batch No. : MKBV0900V, purity 99.0%)

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks on result:
other: Test item is an UVCB
Duration:
48 h
Dose descriptor:
EL0
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks on result:
other: Test item is an UVCB
Duration:
48 h
Dose descriptor:
EL100
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: Test item is an UVCB
Details on results:
The WAF was visually clear throughout the exposure period. No immobility nor any adverse effects were observed at the loading level of 100 mg/L.
Results with reference substance (positive control):
ECso-Value (with 95% confidents limits) of the Reference Item Potassium dichromate
based on nominal concentrations [mg/L], (0 - 24 hours)
Current Study
EC50 = 2.10 mg/L (95% confidence limits 1.92 - 2.43 mg/L)

Valid Range :
0.6 - 2.1 mg/L (according to OECD 202)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
- In Control - No daphnids imobilised or demonstrating any sub-lethal effects; Dissolved =2 concentration > = 8.32 mg/L.
Conclusions:
Based on the nominal loadings of the test item CEDRENE WAHED, the 48 hour-EL10/50/100for Daphnia magna was >100 mg/L. The 48 hour-EL0was 100mg/L.
Executive summary:

Based on the nominal loadings of the test item CEDRENE WAHED, the 48 hour-EL10/50/100for Daphnia magna was >100 mg/L. The 48 hour-EL0was 100mg/L.