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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:
13 August 2019 to 15 August 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019
Report date:
2019

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
13 April 2004
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
3-tert-butyl-1-(3,5-dicarboxyphenyl)-1H-pyrazol-5-aminium chloride
EC Number:
941-661-3
Molecular formula:
C15H18ClN3O4
IUPAC Name:
3-tert-butyl-1-(3,5-dicarboxyphenyl)-1H-pyrazol-5-aminium chloride
impurity 1
Reference substance name:
Unidentified impurity
IUPAC Name:
Unidentified impurity

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Analytical measurements were performed from the control and at the applied test concentration levels at the beginning and at the end of the experiment.

Test solutions

Details on test solutions:
Reconstituted water (ISO medium, according to OECD 202) was used as dilution water for both the range finding and definitive tests. The same composition of reconstituted water was used for the tests and for breeding the test animals. A stock solution with a concentration of 100.0 mg/L (nominal) was prepared with direct addition of the test item, mixed into the test medium (ISO Medium) using ultrasonic bath (approximately 25 minutes). The test solutions were prepared by appropriate dilution of this stock solution just before introduction of the Daphnia (start of the experiment).

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Species and strain: Daphnia magna
Source: István Szent University, 2100 Gödöllő, Páter Károly u. 1, Hungary
Breeding: The Daphnia are bred in Ecotoxicological Laboratory of Citoxlab Hungary Ltd.
The health of the stock animals is continuously monitored by visual daily checking. Abnormal behaviour or significant decrease of population is recorded.
Justification of strain: Daphnia magna is the standard species of the acute immobilisation test.
Number of animals: There were 20 animals in test group and control group respectively, divided into 4 replicates (5 animals / replicate)
Age of the animals: They were less than 24 h old at the beginning of the test
Acclimatization: There was no acclimatization because the water used was similar to the culture water.

Study design

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

Test conditions

Test temperature:
20.0 - 20.5 ºC
pH:
5.30 - 7.78
Dissolved oxygen:
8.0 - 8.6 mg/l
Nominal and measured concentrations:
The following nominal concentrations were tested: 6.25, 12.5., 25.0, 50.0 and 100.0 mg/L.
Test concentrations were analytically determined at the start and at the end of the experiment. The corresponding measured geometric mean test item concentrations were: 6.19, 12.49, 24.49, 49.33 and 99.67 mg/L.
As the analytically measured concentrations deviated not more than 20 per cent from the nominal, the biological results are related to the nominal test item concentrations.
Details on test conditions:
The test duration was 48 hours. Twenty animals, divided into four groups (glass beakers) of five animals each (at least 5 mL test solution/animal) were used at the test concentrations and for the control group as well under static conditions.
The choice of the test concentration was made on the basis of the results of the preliminary range-finding test.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
behaviour
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
82.52 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
behaviour
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
behaviour
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
50 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
behaviour
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
behaviour
Details on results:
In addition to immobility, no abnormal behaviour or appearance of test animals was detected.
There was no immobilization in the control group and the dissolved oxygen concentration at the end of the test in control and test vessels was more than 3 mg/L.
All validity criteria were within acceptable limits and therefore the study is considered as valid.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 48h EC50 value was determined to be 82.52 mg/l (nominal) (95% conf. limits 70.40 - 95.37 mg/l) in this study.