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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:
16.03.2007 to 19.06.2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
yes

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
The study was performed with young daphnids of a clone of the species Daphnia magna Straus. A clone of this species (defined by the supplier as clone 5) was originally supplied by the University of Sheffield/UK in 1992. Since that time, the clone is bred in the laboratories of RCC in reconstituted water of the quality identical to the water quality used in the tests (in respect of pH, main ions, and total hardness) and under temperature and light conditions identical to those of the tests (see below).
At the start of the test, the daphnids used for the test were 6-24 hours old and were not first brood progeny.

Study design

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

Test conditions

Hardness:
Reconstituted test water: analytical grade salts were dissolved in purified
water to obtain the following nominal concentrations:
CaCb x 2H20
MgS04 x 7H20
NaHC03
KCI
Water Hardness
Alkalinity
2.0 mmol/L (= 294 mg/L)
0.5 mmol/L (= 123 mg/L)
0.75 mmol/L (= 65 mg/L)
0.075 mmol/L (= 5.8 mg/L)
2.5 mmol/L (= 250 mg/Las CaC03)
0.8 mmol/L
Ratio of Ca : Mg = 4 : 1 (based on molarity)
Na : K = 10 : 1 (based on molarity)
Test temperature:
20 °C during the test period (Table 3). The test was performed in a temperature-controlled room (room temperature continuously monitored).
Dissolved oxygen:
The test water was aerated prior to the start of the study until oxygen saturation was reached. During the test period the test water was not aerated.
Reference substance (positive control):
yes
Remarks:
For evaluation of the quality of the daphnia clone and the experimental conditions, potassium dichromate is tested as a positive control twice a year.

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC0
Effect conc.:
>= 25 µg/L
Conc. based on:
act. ingr. (dissolved fraction)
Basis for effect:
other: lake of toxicity at water saturation

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
48-hour ECO and 48-hour NOEC > loading rate: 100 mg/L (25 μg/L)
Executive summary:

The acute toxicity of the test item Fluowet I 600 to Daphnia magna was determined in a 48-hour static test according to the EU Commission Directive 92/69/EEC, Part C.2 (1992) and the OECD Guideline for Testing of Chemicals, No. 202 (2004).

Due to the low water solubility of the test item, a supersaturated dispersion of the test item with the loading rate of 100 mg/L was continuously stirred at room temperature in the dark over one hour in a closed vessel. Then, the dispersion was filtered. The undiluted filtrate of the dispersion and dilutions 1: 16, 1 :8, 1 :4, and 1 :2 were used as test media. Additionally, a control was tested in parallel. All test vessels were completely filled and well closed to avoid losses of the test item caused by volatility.

The analytically measured test item concentrations in the analyzed test media samples (dilutions 1:16, 1:8, 1:4, 1:2 and the undiluted filtrate) amounted to 1.1, 3.2, 6.6, 14 and 35 μg/L at the start of the test. At the end of the test, only the concentration of the undiluted filtrate was analyzed due to the absence of a toxic effect. The measured concentration of Fluowet I 600 in the undiluted filtrate decreased to 18 μg/L after 48 hours. The biological results are related to the loading rate of 100 mg/L and the mean measured test item concentration of 25 μg/L, which was calculated as the geometric mean of the test item concentration in the undiluted filtrate measured at the start and the end of the test period.

The biological test results were as follows:

After 24 and 48 hours of exposure, no immobility of daphnids was observed in the control and at test item concentrations up to and including the loading rate of 100 mg/L (25 μg/L).

Consequently, neither the EC100 nor the EC50 could be determined due to the missing toxic effects of the test item up to the loading rate of 100 mg/L (25 μg/L). Thus, the toxicity was above the water solubility limit of the test item in the used test water.

48-hour ECO and 48-hour NOEC > loading rate: 100 mg/L (25 μg/L)