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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report Date:
2019

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: At the end of the exposure period, the replicates were pooled at each concentration before sampling.
- Sampling method:
Frequency at t=0 h and t=48 h
Volume 1.8 mL from the approximate centre of the test vessels
- Sample storage conditions before analysis: Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

Test solutions

Vehicle:
no
Details on test solutions:
The batch of V173671 tested was a light blue powder with a purity of >99 mol% and completely soluble in test medium at the concentrations tested. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with the highest concentration of 100 mg/L applying a 30 minute period of magnetic stirring to accelerate dissolution of the test item in medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure except for the highest test concentration which was clear and very light blue.


Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain/clone: In-house laboratory culture with a known history.
- Justification for species other than prescribed by test guideline: This system has been selected as an internationally accepted invertebrate species.
- Source: In-house laboratory culture with a known history.
- Age of parental stock (mean and range, SD): <4 weeks
- Feeding during test: no
- Food type: /
- Amount: /
- Frequency: /

ACCLIMATION
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: Daily, a suspension of fresh water algae

Study design

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

Test conditions

Test temperature:
19-20°C
pH:
7.9-8.1
Dissolved oxygen:
7.9-9.2 mg/L
Nominal and measured concentrations:
0.10, 1.0, 10 and 100 mg/L.
Samples taken from the highest test concentration and the control were analysed. No test item was detected in the control samples. The measured concentration at the start of the test in the highest test concentration was 115 mg/L. During the exposure period, the concentration decreased to 70% of initial, i.e. was 80 mg/L at the end of the test.
Based on these results, the average exposure concentration was calculated to be 96 mg/L and used to express effect parameters.

Details on test conditions:
TEST SYSTEM
- Test vessel: 60 mL, all-glass
- Type (delete if not applicable): static
- Aeration: No aeration of the test solutions.
- No. of organisms per vessel: 5 per vessel containing 50 mL of test solution
- No. of vessels per concentration (replicates): 4 for the control and the highest test concentration.
2 per intermediate test concentration.
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).

Composition of medium M7:
The following salts (analytical grade) were added to tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
CaCl2.2H2O 211.5 mg/L
MgSO4.7H2O 88.8 mg/L
NaHCO3 46.7 mg/L
KCl 4.2 mg/L
The hardness of test medium expressed as CaCO3: 180 mg/L with a pH between 6 and 9.

The following salts and vitamins were added to freshly prepared test medium (see section 4.8.2.2) to reach the following concentrations:

Salts: H3BO3 0.71 mg/L
FeSO4.7H2O 0.25 mg/L
MnCl2.4H2O 0.090 mg/L
LiCl 0.076 mg/L
RbCl 0.018 mg/L
SrCl2.6H2O 0.038 mg/L
Na2MoO4.2H2O 0.015 mg/L
NaBr 0.0040 mg/L
CuCl2.2H2O 0.0042 mg/L
ZnCl2 0.013 mg/L
CoCl2.6H2O 0.010 mg/L
KI 0.0032 mg/L
Na2SeO3 0.0022 mg/L
NH4VO3 0.00057 mg/L
Na2EDTA.2H2O 0.62 mg/L
Na2SiO3.5H2O 7.5 mg/L
NaNO3 0.27 mg/L
KH2PO4 0.14 mg/L
K2HPO4 0.18 mg/L
Vitamins: Thiamine hydrochloride 75.0 µg/L
B12 1.0 µg/L
Biotin 0.75 µg/L


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: A daily photoperiod of 16 hours.
- Light intensity: not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality) At 24 hours and at 48 hours.
pH and Dissolved oxygen At the beginning and at the end of the test, for the highest concentration and the control.
Temperature of medium Continuously in a temperature control vessel, beginning at the start of the test.


VEHICLE CONTROL PERFORMED: yes (medium)

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.00, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: A combined limit/range-finding test was performed
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 96 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 96 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
No immobility was observed in the control and at any of the test concentrations throughout the exposure period. The responses recorded in this test allowed for reliable determination of an EC50.
Results with reference substance (positive control):
The 24h-EC50 in this reference test with K2Cr2O7 was within the expected range of 0.6 and 2.1 mg/L as specified in ISO International Standard 6341, October 2012. The 48h-EC50 was within the expected range of 0.28 and 0.75 mg/L, which is based on reference tests performed at the Test Facility during the last ten years.
The 24h-EC50 was 0.92 mg/L with a 95% confidence interval between 0.78 and 1.1 mg/L.
The 48h-EC50 was 0.55 mg/L with a 95% confidence interval between 0.47 and 0.64 mg/L.
Reported statistics and error estimates:
See table below for statistics

Any other information on results incl. tables

Effect Parameters

Parameter

V173671

Average exposure concentration (mg/L)

24, 48h-EC50

>96

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In conclusion, the 48h-EC50 for Daphnia magna exposed to V173671 was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 96 mg/L.
Executive summary:

The objective of the study was to evaluate V173671 for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC50at 24 and 48 hours of exposure.

The study procedures described in this report were based on the OECD guideline No. 202, 2004.

The batch of V173671 tested was a light blue powder with a purity of >99 mol% and completely soluble in test medium at the concentrations tested.

A combined limit/range-finding test was performed. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to 100 mg/L, in a limit test. In addition ten daphnids per group (5 per replicate, duplicate) were exposed to 0.10, 1.0 and 10 mg/L in the combined range-finding test. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test.

Samples taken from the highest test concentration and the control were analysed. No test item was detected in the control samples. The measured concentration at the start of the test in the highest test concentration was 115 mg/L. During the exposure period, the concentration decreased to 70% of initial, i.e. was 80 mg/L at the end of the test. Based on these results, the average exposure concentration was calculated to be 96 mg/L and used to express effect parameters.

No immobility was observed in the control and at any of the test concentrations throughout the exposure period.

The study met the acceptability criteria prescribed by the study plan and was considered valid.

In conclusion, the 48h-EC50for Daphnia magna exposed to V173671 was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 96 mg/L.