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Ecotoxicological information

Short-term toxicity to fish

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short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08 - 12 Apr 2013
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
according to guideline
OECD Guideline 203 (Fish, Acute Toxicity Test)
Version / remarks:
GLP compliance:
yes (incl. QA statement)
Staatsministerium für Umwelt und Landwirtschaft, Germany
Analytical monitoring:
Details on sampling:
- Concentrations: 0 and 100 mg/L
- Sample storage conditions before analysis: stored deep frozen (≤ -18 °C) at the test facility
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution was prepared by weighing 1000 mg test item and filling up to 5000 mL with test medium (= stock solution A, corresponding to a concentration of 100.0 mg test item/L). The test solutions of the chosen concentrations were prepared directly in the test vessels immediately before the transfer of the fish into the test vessels.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control
Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
- Common name: rainbow trout
- Source: purchased from the fish farm „Forellenhof Trostadt“, Reurieth, Germany; held and bred in the testing facility under standardised laboratory conditions
- Age at study initiation (mean and range, SD):
- Length at study initiation (length definition, mean, range and SD): 4.8 ± 0.2 cm
- Weight at study initiation (mean and range, SD): 0.83 ± 0.2 g
- Feeding during test: none

- Acclimation period: 62 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: fish food until 24 hours before the test was started
- Feeding frequency: daily
- Health during acclimation (any mortality observed): The mortality of the fish during the acclimatisation period was 0.3 %.

Test type:
Water media type:
Limit test:
Total exposure duration:
96 h
200 mg/L CaCO3
Test temperature:
13.4 - 14.5 °C
7.60 - 7.93
Dissolved oxygen:
8.07 - 8.93 mg/L
Nominal and measured concentrations:
Nominal: 0 and 100 mg/L
Recoveries: 100.9% at 0 h and 97.5% at 96 h
Details on test conditions:
- Test vessel: stainless steel container
- Material, size, headspace, fill volume: stainless steel (approx. 25 L volume), fill volume 10 L, headspace: 15 L
- Aeration: yes
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.83 g fish/L

- Source/preparation of dilution water: reconstituted water according to ISO 6341
- Conductivity of deionised water: 1.0 µS/cm
- Intervals of water quality measurement: pH, oxygen concentration and temperature daily

- Adjustment of pH: no
- Photoperiod: 16 h light : 8 h dark, daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Number of dead fish in each test vessel (including abnormalities), 3, 6, 24, 48, 72 and 96 hours after start of exposure
Reference substance (positive control):
not required
96 h
Dose descriptor:
Effect conc.:
> 100 mg/L
Nominal / measured:
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
96 h
Dose descriptor:
Effect conc.:
>= 100 mg/L
Nominal / measured:
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Details on results:
- No mortality was observed during the study
- Other adverse effects control: none
- Abnormal responses: No visible signs of abnormalities of the surviving test fish were observed at any time of inspection.
Reported statistics and error estimates:
Since a limit test was performed, it was not necessary to conduct a calculation or statistical evaluation.
Sublethal observations / clinical signs:

The measured concentrations of test item in the test solutions at 0 and 96 hours after application were 101 and 98 % of the nominal concentrations respectively. Therefore, all toxicity results are based on

the nominal concentrations.

Validity criteria fulfilled:

Description of key information

LC50 (96 h) > 100 mg/L (Oncorhynchus mykiss; OECD 203)

Key value for chemical safety assessment

Additional information

One study is available on the short-term toxicity of Reaction mass of 2-(3,4-dimethyl-1H-pyrazol-1-yl)succinic acid and 2-(4,5-dimethyl-1H-pyrazol-1-yl)succinic acid to fish. The study was conducted as a limit test according to OECD Guideline 203 and GLP (Juckeland, 2013). The test organism Oncorhynchus mykiss was exposed to the test substance at a nominal concentration of 100 mg/L for 96 hours. No mortality was observed during the study, and the LC50 is thus determined to be > 100 mg/L (nominal).