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:
2002-12-11 to 2003-02-04
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD study, GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Sampling method: Samples for analytical determinations were taken from all test concentrations at test start, at 24 hours (old and new test solutions) and at the end of the test (48 hours).
- Sample storage conditions before analysis: -18°C to -25°C

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: As the test item is prone to hydrolysis (please refer to section 5.1.2), the stock solution was prepared as close as practically possible to the start of the test. These treatments fulfill the recommendations of the OECD for poorly soluble substances subject to hydrolysis (OECD, 2000). To maintain the test concentrations constant during exposure, the test was performed under semi-static conditions. The stock solutions was renewed at 24 hours of the test. Each stock solution was prepared as follows: 200.3 mg test item (or 199.9 mg at 24 hours of the test) was weighed, dissolved in 2000 mL test medium. The stock solution was homogenised by ultrasonic treatment for about 10 minutes and stirred for about 5 minutes. Due to the poor solubility of the test item, the not dissolved parts of the test item were separated by filtration (0.45 µm). The filtration was carried out under pressure with a flow rate not greater than 100 mL/min. The filter was preconditioned with 1000 mL of the stock solution. Afterwards, the rest of the stock solution was filtered and the filtrate taken to prepare the test concentrations. Additionally, due to the light sensitivity of the test item, the glass vessel were covered with aluminium foil and the filtration process took place in the dark.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna Straus
- Source: laboratories of the test facility
- Age at study initiation: less than 24 hours

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
ca. 280 mg/L CaCO3
Test temperature:
20.1 - 21.0°C
pH:
8.0 to 8.1.
Dissolved oxygen:
96% and 100%
Nominal and measured concentrations:
4.3, 9.4, 21, 45 and 100 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 mL beakers containing 100 mL test medium
- Renewal rate of test solution (frequency/flow rate): 24 hours
- No. of organisms per vessel: 20 Daphnia per concentration
- No. of vessels per concentration: two beakers per test concentration

TEST MEDIUM / WATER PARAMETERS
- in accordance to the guideline

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light daily, 8 hours dark

TEST CONCENTRATIONS
- Spacing factor for test concentrations: ca. 2.2
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC0
Effect conc.:
9.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Mortality of control: no
- Since the test item is prone to hydrolysis (please refer to section 5.1.2), no suitable method was available to quantify the test item in water. Hence all the biological results are related to the nominal concentrations of the test item.
Results with reference substance (positive control):
The quality of the Daphnia is checked at least every 3 months by determining the EC50 value (24 h) for the reference item potassium dichromate.
Reference control on December 04, 2002: EC50 = 0.9 mg/L

Applicant's summary and conclusion