2-Propenamide, N-[4-[[(4,6-dimethyl-2-pyrimidinyl)amino]sulfonyl]phenyl]-2-methyl-

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

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:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted April 13, 2004

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Frequency: at t=0 h and t=48 h
- Sampling method: 3.0 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.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The batch of V123109 tested was a white crystalline powder with a purity of >95% and not completely soluble in test medium at the loading rates initially prepared. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with a loading rate of 100 mg/L applying a 12-minutes treatment with ultrasonic waves followed by a 3-day period of magnetic stirring to ensure maximum dissolution of the test item in medium. Thereafter, the aqueous Saturated Solution (SS) was filtered through a 0.45 μm membrane filter (RC55, Whatman) and used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the SS in test medium. All test solutions were clear and colorless at the end of the preparation procedure.
Any residual volumes were discarded.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: In-house laboratory culture with a known history.
- Age of parental stock (mean and range, SD):
- Feeding during test: no
- Temperature of medium: 18-22°C
- Feeding: Daily, a suspension of fresh water algae.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

8-22°C, constant within 2°C

pH:

7.5-8

Dissolved oxygen:

7.8-9 mg/L

Nominal and measured concentrations:

Solutions containing 1.0%, 10% and 100% of a SS prepared at a loading rate of 100 mg/L.
Analyses of the samples taken from the undiluted SS showed an actual concentration of 73 mg/L at the start of the test. This concentration remained stable throughout the test duration, i.e. was 101% of initially measured at the end of the test. Based on these results, effect parameters were based on the measured concentration.

Details on test conditions:

TEST SYSTEM
- Test vessel: 60 mL, all-glass
- Aeration: no
- No. of organisms per vessel: 5 per vessel containing 50 mL if test solution
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle 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).

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality) at 24 hours and at 48 hours.


RANGE-FINDING STUDY
- Test concentrations: Solutions containing 1.0%, 10% and 100% of a SS prepared at a loading rate of 100 mg/L.
- Results used to determine the conditions for the definitive study: combined range-finding/limit study

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 73 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

maximum nominal concentration: 100 mg/L

Details on results:

No immobility or other effects were observed in the control during the exposure thus this test was considered valid. Also in the remaining groups no effects were observed.

Reported statistics and error estimates:

24h-EC50 >73 mg/L
48h-EC50 >73 mg/L

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the 48h-EC50 for Daphnia magna exposed to V123109 exceeded a measured concentration of 73 mg/L, which was considered to be the maximum solubility limit of V123109 in medium.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

73 mg/L