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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:
From Sept. 2010 to Nov. 2010
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to standard guidelines in compliance with GLP. Measured concentrations were below the limit of quantification of the analytical method.
Justification for data waiving:
other:
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
other: OECD Series on testing and assessment No. 23: Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000
Deviations:
no
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 12-hydroxystearic acid (CAS N°106-14-9, EC N°203-366-1)
- Substance type: Fatty acid
- Physical state: Solid / white to yellowish
- Storage condition of test material: At room temperature (15 - 25 °C), in the dark
- Expiration date of the lot/batch: 09 April 2011

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Duplicate samples from the freshly prepared test media of all test concentrations and the control were taken at the start of the test. For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the test media of all test concentrations and the controls were collected at the end of the test (after 48 hours) by pouring together the contents of the test beakers of each treatment.
- Sample storage conditions before analysis: All samples were stored in a freezer (≤ - 10 °C), protected from light until analysis was performed

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Concentrations: A filtrate of nominal 100 mg test item/L and dilutions of 1:3, 1:9, 1:27, 1:81. Additionally, a control was tested in parallel.
- Method: The test item was not well soluble in test water. To avoid physical effects of undissolved test item on Daphnia no concentration above the solubility limit of the test item in test water was tested. Therefore, a supersaturated stock solution of 100 mg test item/L was prepared by suspending 80.4 mg of test item in 804 mL of test water for preparing the test concentration. The stock suspension was stirred for 24 hours in the dark to dissolve as much test item as possible. Then, the undissolved test item was separated by filtration (0.45 µm cellulose nitrat filter) and the filtrate was used as test medium. The test media were prepared just before introduction of Daphnia (= start of the test).
- Controls: Yes
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The appearance of the test substance in the test media was observed at the start of the test and after 24 and 48 h test duration in the only test concentration. No remarkable observations were made.


Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain: Clone 5
- Source: In house laboratory culture (i.e. IBACON testing laboratory)
- Age at study initiation (mean and range, SD): 6.25 to 21.5 h old
- Method of breeding: The cultivation of the parental Daphnia was performed in reconstituted water of a similar quality with regards to pH, the constituent salts and total hardness as the test water used in the test. The test organisms were not first brood progeny
- Food type: Green algae (Desmodesmus subspicatus) freshly grown in the lab
-Frequency: Daily

ACCLIMATION
- Was not necessary, since the test was performed in the same medium as the culturing

Study design

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

Test conditions

Hardness:
250 mg/L as CaCO3
Test temperature:
20 - 21 °C
pH:
7.6 - 7.7
Dissolved oxygen:
6.5 - 8.9 mg/L at test start
9.0 - 9.2 mg/L at test end
Nominal and measured concentrations:
- Nominal: a filtrate of nominal 100 mg/L and dilutions of 1:3, 1:9, 1:27 and 1:81. In addition, a control.
Details on test conditions:
TEST SYSTEM
- Test vessel: Glass beakers
- Type (delete if not applicable): Closed with lids
- Material, size, headspace, fill volume: Glass beakers of 100 mL volume containing approximately 60 mL of test medium.
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel: 20 Daphnia per control and test concentration, divided into 4 groups of 5 animals, each group in 50 mL test medium



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt "M4" reconstituted water
- Alkalinity: 0.9 mmol/L
- Culture medium different from test medium: No


OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Photoperiod: 16 h light: 8 h dark
- Light intensity: 940 - 1150 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility of the Daphnia was determined by visual observation after 24 and 48 h. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker were considered to be immobile (even if they could still move their antennae).
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: filtrate
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: filtrate
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: filtrate
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: No
- Mortality of control: No
- Other adverse effects control: No
Results with reference substance (positive control):
- Results with reference substance valid: Yes
- EC50: 1.59 mg/L (48 h) indicating that the sensitivity of the Daphnia was consistent with the level proposed by the OECD 202 guideline
- NOEC: 0.62 mg/L (48 h)
- LOEC: 1.4 mg/L (48 h)
- Other: Test was not conducted parallely with this study, but a while before in January 2010.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under the test conditions, the 48 h EC50 of the test material was > 100 mg/L (nominal). The 48 h NOEC and LOEC were determined to be >=100 and > 100 mg/L (nominal), respectively.
Executive summary:
A study was conducted to determine the acute toxicity of 12 -hydroxystearic acid to Daphnia magna in a static 48 h immobilisation test (OECD Guideline 202 and EU method C.2).

The test item was not well soluble in test water. To avoid physical effects of undissolved test item on Daphnia, no concentration above the solubility limit of the test item in test water was tested. A supersaturated stock solution of 100 mg/L was prepared by suspending the substance in test water. The stock suspension was stirred for 24 hours in the dark , then undissolved substance was separated by filtration.

Daphnia magna (20 per dose) were exposed to the filtrate at 100 mg/L (nominal) and dilutions of 1:3, 1:9, 1:27 and 1:81 for 48 h. Immobility of theDaphnia was determined by visual observation after 24 and 48 h. Analytical verification of the test concentrations were conducted on samples collected at start and after 48 h.

Under the test conditions, the 48 h EC50 of the test material was > 100 mg/L (nominal). The 48 h NOEC and LOEC were determined to be >=100 and > 100 mg/L (nominal), respectively.