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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:
26th April 2006 - 28th April 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report date:
2006

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Test material form:
solid: particulate/powder
Details on test material:
Light pink tinted powder
Specific details on test material used for the study:
Physical state/Appearance: Lightly pink tinted powder
Batch: Batch ref Y12511/002/001, bottle no. 287981)
Purity: 99.8% w/w
Expiry Date: not specified
Storage Conditions: Room temperature in the container it was received

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
The concentrations of UL125 in test solutaions were sampled at 0 and 48 hours.
At the start of the test, the excess test solutions were sampled and at the end of the test, one replicate of both controls and single concentration were sample.

Test solutions

Vehicle:
yes
Remarks:
Dimethylformamide
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A 5.0 ml stock concentration of UL125, nominally 320000 mg/l, was prepared by dissolving 1.600 g of UL125 in dimethylformamide. The test solution was prepared by the addition of 1000 μl of this stock solution to 1000 ml of dilution water with thorough stirring. A solvent control was similarly prepared by the addition of 100 μl of dimethylformamide to 1000 ml of dilution water, to give final solvent concentrations of 100 μl/l (0.01% v/v) in both cases. both additions were made sub surface, gradually, by microlite syringe, into solutions viorously stirred by megnetic follower.
- Controls: as specified above - solvent control and dilution water control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Dimethylformamide
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 100 μl/l
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): the resultant solutions were clear and colourless, but the test substance contriation contained suspended white particles

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Dapnia Magna
- Strain/clone: Clone 5
- Source: Originally obtained from IRCHA, France, subsequently characterised by Sheffield University, UK
- Age of parental stock (mean and range, SD): 16 +/- 1 day old and maintained with a twice weekly renewal of reconstituted water medium.
- Feeding during test - The test solutions were not aerated and the Daphnia were not fed during the course of the study

ACCLIMATION
Cultures maintained under test conditions, free from disease

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:
Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing.

Study design

Test type:
static
Water media type:
other: Elendt's M4 Daphnia Medium
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
Total hardness as CaCo3 - 199 mg CaCO3/L
Test temperature:
20 +/- 1
pH:
7.9 - 8.0
Dissolved oxygen:
9.0 - 9.4 mg/l
Conductivity:
574 μS/cm
Nominal and measured concentrations:
Nominal 32 mg/l; measured 0 hours 30 mg/L; 48 hours 21 mg/L. Mean measured conc as percentange of nominal conc 66%
solvent control at 0 and 48 hours
Details on test conditions:
TEST SYSTEM
- Test vessel: Borosilicate glass beakers of 250ml niminal capacity
- Type (delete if not applicable): sealed with loose fitting glass lids
- Material, size, headspace, fill volume: borosilicate 250 mL, filled to 200ml of test solution providing appoximate depth of 60nm
- Aeration: none
- Type of flow-through (e.g. peristaltic or proportional diluter): static
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M7 medium prepared as described in the OECD Test guideline

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod:16 hours light and 8 hours dark with 20 minute transition periods.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Any immobilization or adverse reactions to exposure were recorded at 24 and 48 hours after the start of exposure. The criterion of effect used was that daphnia were considered to be immobilized if they were unable to swim within 15 seconds after gentle agitation.

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 21 mg/L
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 21 mg/L
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
> 21 mg/L
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
21 mg/L
Details on results:
- Behavioural abnormalities:
- Observations on body length and weight: none
- Other biological observations: No immobilised Daphnia were observed.
- Mortality of control: No immobilization was observed in the control and solvent control vessels
- Other adverse effects control: No sub-lethal effects of exposure were observed throughout the test.
Reported statistics and error estimates:
An estimate of the EC50 values was given by inspection of the immobilization data.
The No Observed Effect Concentration (NOEC) was determined by inspection of the immobilization data, with no immobilization.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The No Observed Effect Concentration (NOEC) is defined as the highest tested concentration in which there was no immobility obeserved effect in the daphnia within the period of the test.

Therefore 48 hour NOEC = 21 mg/l

The LC 100 is defined as the lowest test concentration that caused 100% mortality within the period of the test.

Therefore 48 hour EC100 => 21mg/l

21 mg/l was considered to be the limit of solubility of UL125 under test conditions.

There was no immobility in the dilution water control or solvent control.

No symptoms of toxicity were observed in this study.

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