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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:
other information
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

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

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
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report): NI 10773 Iodid
- Physical state: solid
- Analytical purity: 99.2%
- Impurities (identity and concentrations): PD 733 < 0.06% / PD 727 < 0.06% / RRT 1,86 < 0.06% / RRT 1,87 0.08% / unspecified impurities < 0.06%
- Lot/batch No.: 0001
- Expiration date of the lot/batch: 31 March 2015
- Storage condition of test material: typically +25 °C or coller, in a well closed container

Test solutions

Details on test solutions:
The water solubility of the test item in medium was tested in a pre-experiment.
Due to the observed low water solubility a stock dispersion was prepared by
stirring 32 mg test item/L test medium (see 4.4) at room temperature in the dark
for 48 hours to dissolve a maximum amount of the test item. A stock solution
was withdrawn from the middle of the preparation vessel by suction. Transfer of
undissolved test item was avoided as far as possible. Adequate aliquots of the
withdrawn phase were diluted with test medium to prepare the test solutions with
the lower test item concentrations. The preparation of the stock dispersion was
based on the OECD Guidance Document No. 23 on Aquatic Toxicity Testing of
Difficult Substances and Mixtures (2000).
The solubility of the test item in test medium was very low, flocculation at the
surface and the bottom of the beakers during the test period was observed in the
stock solution and at dilutions of 1:3.2 and 1:10.
The test item concentrations were selected based on the results of a non-GLP
range-finding test. The large spacing factor of approximately 3.2 was selected
since a flat dose response relationship was observed in the range finding test.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: German Federal Environment Agency (UBA)
- Age at study initiation (mean and range, SD): max. 24 h
- Weight at study initiation (mean and range, SD):
- Method of breeding: Daphnia magna was bred as single culture (one daphnid per 100 mL) in Elendt
M4 medium. The pH-value of the aerated water was within a range of 6.0 – 9.0.
The dissolved oxygen was above 60 % saturation and the total hardness 140 -
250 mg/L (as CaCO3)
- Feeding during test: The animals were fed with single cell green algae
(Desmodesmus subspicatus, formerly Scenedesmus subspicatus) at least three
times a week.

Study design

Test type:
static
Water media type:
not specified
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
250 mg/L as CaCO3).
Test temperature:
19.3 – 19.9 °C
pH:
7.41 – 7.84
Dissolved oxygen:
99 %
Nominal and measured concentrations:
- Test concentrations: 0.32 - 32.0 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: glass beaker
- Material, size, headspace, fill volume: glass, 100 mL, 50 mL
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

OTHER TEST CONDITIONS
- Photoperiod: 16 hours photoperiod / 8 hours darkness daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Justification for using less concentrations than requested by guideline: A flat dose response relationship was observed in the range finding test.
- Test concentrations: 0.32 - 32.0 mg/L

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC0
Effect conc.:
< 0.097 mg/L
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
0.243 mg/L
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
11.3 mg/L
Results with reference substance (positive control):
- Results with reference substance valid? Yes

The results indicate an EC50 (24 h) of the reference item potassium dichromate of
2.0 mg/L. Since the results fall within the historical data generated with the
reference item at the testing facility and are within the range of 0.6 - 2.1 mg/L
recommended by the test guideline OECD 202, the daphnids were suitable for
the determination of the toxicological effects of the test item.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
According to the results of the test, the EC50 (48 h) is 0.243 mg test
item/L (actual measured). The EC0 (48 h) is below
0.0968 mg test item/L (actual measured), the EC100 (48 h) was
observed at 11.3 mg test item/L (actual measured).