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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:
2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study without restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
4,5,6,7-tetrahydro-1H-benzotriazole
EC Number:
229-858-6
EC Name:
4,5,6,7-tetrahydro-1H-benzotriazole
Cas Number:
6789-99-7
Molecular formula:
C6H9N3
IUPAC Name:
4,5,6,7-tetrahydro-1H-1,2,3-benzotriazole
Details on test material:
Physical state, appearance: solid, white
Storage conditions: room temperature

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Sampling method: samples of each test item concentration and the control collected at exposure initiation and at exposure termination directly from the test vessels with daphnids were analyzed

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Elendt M7 medium (OECD 211)
The medium was prepared on the basis of deionised water by adding stock solutions of reagent-grade chemicals. The stock solutions for culturing Daphnia magna were renewed on a regular basis. The alkalinity determined for Elendt M7 medium was 64 mg/L as NaHCO3, the hardness was 158 mg/L as CaCO3 .

The content of flask with stock solution (400mg/L) was heterogeneous (visible non-dissolved particles), therefore it was sonicated for 5 minutes. The resulting test item concentration of 400 mg/L was visually homogeneous and transparent. The lower test item concentrations were prepared by sequential dilutions with the Elendt M7 medium in a ratio 1 : 1, volume per volume. The control was Elendt M7 medium (500 mL). The test item concentrations were visually homogeneous and transparent directly after preparation and throughout exposure period.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Source: Standard laboratory culture maintained in the Institute of Industrial Organic Chemistry, Branch Pszczyna, Department of Ecotoxicology, Laboratory of Aquatic Toxicology
- Age at study initiation (mean and range, SD): < 24 hours, not first brood progeny
- Method of breeding: Daphnia magna was cultured in glass beakers of 150 mL volume (one parent per vessel) at room temperature 18 – 22o C with the light : dark ratio of 16 h : 8 h (electronic time programmer, KANLUX, Poland). The culture was maintained in Elendt M7 medium.
- Feeding during test: none

ACCLIMATION
- Acclimation conditions (same as test or not): yes
- Type and amount of food: mixture of two species Pseudokirchneriella subcapitata: Desmodesmus subspicatus (in 2:1 ratio) algae suspension. Group B vitamins and micronutrients necessary for proper growth were supplied with lyophilized Spirulina sp. suspension.

Study design

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

Test conditions

Test temperature:
19.4 – 20.5ºC
pH:
at exposure initiation 7.71 – 7.81
at exposure termination 7.69 – 7.79
Dissolved oxygen:
exposure initiation 9.0 – 9.1 mg/L
exposure termination 8.8 – 9.0 mg/L
Conductivity:
(control) at exposure initiation 450 μS/cm
Nominal and measured concentrations:
400, 200, 100, 50, 25, 12.5, 6.25 mg/L (nominal)
Details on test conditions:
TEST SYSTEM
- Test vessel: glass beakers
- Type (delete if not applicable): covered with transparent lids in order to minimize evaporation and to prevent accidental contamination
- Material, size, headspace, fill volume: 150 mL, filled with 100mL test solution
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16:8 light:dark


- Range finding study
At exposure termination, in the control and in the test item concentrations of 1.0, and 10 mg/L no immobilization of Daphnia magna was observed. In the test item concentration of 100 mg/L the immobilization of Daphnia magna was 50%. The results are given in Table 2. At exposure termination in the test item concentration of 10 mg/L 30% of Daphnia magna was trapped on the surface. At exposure termination in the test item concentration of 100 mg/L 50% of Daphnia magna was trapped on the surface. The Daphnia magna which were not immobile were trapped on the surface.
In a stability test in AAP medium for algae, the concentration was within + 10% of the nominal concentration over 72 h under conditions of an algae toxicity test without showing any tendency for a decrease. Therefore, the definitive test was performed under static test conditions.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
205.92 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: nominal concentrations verified analytically
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
50 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: nominal concentrations verified analytically
Details on results:
At exposure termination, in the control and in the test item concentrations of 6.25, 12.5, 25 and 50 mg/L no immobilization of Daphnia magna was observed. In the test item concentrations of 100, 200, 400 mg/L the immobilization of Daphnia magna was 30, 55 and 70%, respectively.
At exposure termination the percentage of trapped Daphnia magna on the surface was 25, 50, 100, 100, 100 and 100% in the test item concentrations of 12.5, 25, 50, 100, 200 and 400 mg/L, respectively.
At exposure initiation the determined test item concentrations were in the range of 96.37 – 103.04% of the nominal concentration.
At exposure termination the determined test item concentrations were in the range of 99.58 – 102.24% of the nominal concentration. Therefore, the test item concentrations were stable under test conditions and the endpoint values were determined based on the nominal test item concentrations.
EC50/24 h value is above 400 mg/L, EC50/24 h value is above 400 mg/L.

Validity criteria
In the definitive test the validity criteria were met according to OECD Guideline No. 202 (2004):
- The percentage of immobilization of Daphnia magna in the control was 0% (criterion: not more than 10%),
- The dissolved oxygen concentrations in the test vessels were within the range of 8.8 – 9.1 mg/L (criterion: not less than 3 mg/L).
Results with reference substance (positive control):
The test with the reference material potassium dichromate was performed from June 16, 2017 to June 18, 2017. Five concentrations of the reference material ranging from 0.32 to 3.2 mg/L and a control were used. There were four replicates of each reference material concentration and the control.
NOEC 48h 0.56mg/L
EC50 48h 0.84 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes

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