2-[4-(4-Alkoxyphenyl)-(pyridin-2-yl)-heteromonocyclyl]phenol

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:

Study Initiation Date - 27 May 2021; Experiment Start Date - 28 May 2021; Experimental End Date - 10 June 2021; Study completion date - 02 July 2021.

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Test Item: FAT 75637/B TE
Physical Appearance: Light yellow powder
Purity: 99.4 % all organic constituents; 95.0 % main constituent
Batch No: AT-0063765400
Manufactured Date: 21st April 2020
Expiry Date: May 27th, 2025

Analytical monitoring:

yes

Details on sampling:

All the test concentrations along with the negative control were analyzed for the test item concentration at the start and end of first and second renewal. For analysis, duplicate set of composite samples were drawn from prepared test concentrations. Analysis was conducted using a validated analytical method. The criteria for acceptance of analysis results of test concentration were 80 to 120 % of nominal concentration with ≤20 % RSD.

Vehicle:

no

Details on test solutions:

To prepare test concentration of 50 (G2) mg/L, 50 mg test item was ground using test medium and made up to 500 mL in a volumetric flask using test medium and sonicated for 30 minutes. 1 L of test medium itself without any addition of the test item was used as negative control (G1). 150 mL each of negative control and test item concentration dispensed into respective replicate (4 replicates were maintained for each group).

Test organisms (species):

Daphnia magna

Details on test organisms:

Less than 24 hour old neonates of daphnia were exposed to a limit test concentration 50 mg/L of the test item for 48 hours in semi-static mode of test with the renewal of test medium at 24 hour interval. Certain concentrations result in certain percentage of daphnia no longer being capable of swimming at 48 hours. The effects on the organisms were assessed at 24 and 48 hours interval and the EC50 value was calculated. Neonates (Daphnia <24-hour old): One day prior to the start of the treatment, 25 adults were incubated in approximately 2 L of reconstituted water (Acclimatization). The following day, the young ones hatched which were less than 24 hour old (not first brood progeny) were collected and used in the tests.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

250 mg CaCO3 and 0.8 mg C/L

Test temperature:

19.9 to 20.3 °C

pH:

7.65 to 7.71

Dissolved oxygen:

6.8 to 7.1 mg O2/L

Nominal and measured concentrations:

Definitive test: 50 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Beakers
- Type: Loosely covered
- Material, size: 250 mL glass beakers.
- Volume of solution: 30 mL
- Aeration: No
- Renewal rate of test solution: once every 24 hours.
- No. of organisms per vessel: 5 daphnia
- No. of vessels per concentration: four replicates
- No. of vessels per control: 5 daphnia
- No. of vessels per vehicle control: four replicates

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- Total organic carbon: 0.8 mg/L
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Photoperiod: 16 hour light & 8 hour dark
- Light intensity: 643 to 648 lux

EFFECT PARAMETERS MEASURED: Immobilization

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 0.01, 0.1, 1, 10 and 50 mg/L
- Results used to determine the conditions for the definitive study: There was no immobilization of daphnia at the tested concentrations of 0.01, 0.1, 1, 10 and 50 mg/L at 48 h post treatment.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Test Item Solubility

FAT 75637/B was tested for its solubility in the test medium and formed semi-transparent cream coloured formulation with visible solid particles in test medium at 50 mg/L.

Definitive Test

There was no immobilization of daphnia in the negative control and at the limit test concentration of 50 mg/L at 24 and 48 hours of exposure. The EC50, LOEC and NOEC value for immobilization of daphnia at 24 and 48 hours are higher than 50 mg/L based on the nominal concentration.

Analysis of Test Concentration

The stability test results concluded that the test item was stable in the test medium at 48 h at 1.012 mg/L and 151.000 mg/L nominal concentrations. The active ingredient concentration analysis in all test concentrations showed that the recovery with the nominal concentration was 88.548% (RSD was 2.121%) at the start of the first renewal (start of the test – 0 hour), 103.290 % (RSD was 13.668 %) at the end of first renewal, 82.953 % (RSD was 4.072) at the start of second renewal and 92.305 % (RSD was 7.059 %) at the end of the second renewal (end of the test - 48 hour) indicating that the results were within the acceptable limit (80 to 120 % of the nominal concentration with an RSD of <20 %).

VALIDITY OF THE TEST

This test was considered valid, because:

• There was no immobilization of daphnia in the negative control during the test period, which is within the allowed 10 percent immobilization of daphnids.

• The dissolved oxygen concentration at the end of the test was more than ≥3 mg/L in negative control and treatment test vessels.

Validity criteria fulfilled:

yes

Conclusions:

The EC50, LOEC and NOEC value for immobilization of daphnia at 24 and 48 hours are higher than 50 mg/L based on the nominal concentration.

Executive summary:

The acute immobilization effect of the test item FAT 75637/B TE was studied on Daphnia magna for 48 hours. This study was conducted according to OECD test guideline 202 in GLP-certified laboratory. In definitive test, daphnids, less than 24 hours old, were exposed to the limit test concentration of 50 mg/L along with a negative control. The number of daphnids immobilized was recorded at 24 and 48 hours exposure. There was no immobilization of daphnids in the negative control and at the tested concentration of 50 mg/L at 24 and 48 hours of exposure. The stability test results concluded that the test item was stable in the test medium at 48 hour at 1.012 mg/L and 151.000 mg/L nominal concentrations. The active ingredient concentration analysis in all test concentrations showed that the recovery with the nominal concentration was 88.548 % (RSD was 2.121 %) at the start of the first renewal (start of the test – 0 h), 103.290 % (RSD was 13.668 %) at the end of first renewal, 82.953 % (RSD was 4.072) at the start of second renewal and 92.305 % (RSD was 7.059 %) at the end of the second renewal (end of the test - 48 hour) indicating that the results were within the acceptable limit (80 to 120 % of the nominal concentration with an RSD of <20 %). The EC50, LOEC and NOEC value for immobilization of daphnia at 24 and 48 hours are higher than 50 mg/L based on the nominal concentration of the test item.

Description of key information

The EC50, LOEC and NOEC value for immobilization of daphnids at 24 and 48 hours are higher than 50 mg/L based on the nominal concentration of the test item.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

50 mg/L

Additional information

The acute immobilization effect of the test item FAT 75637/B TE was studied on Daphnia magna for 48 hours. This study was conducted according to OECD test guideline 202 in GLP-certified laboratory. In definitive test, Daphnia magna, less than 24 hours old, were exposed to the limit test concentration of 50 mg/L along with a negative control. The number of daphnids immobilized was recorded at 24 and 48 hours exposure. There was no immobilization of daphnids in the negative control and at the tested concentration of 50 mg/L at 24 and 48 hours of exposure. The stability test results concluded that the test item was stable in the test medium at 48 hour at 1.012 mg/L and 151.000 mg/L nominal concentrations. The active ingredient concentration analysis in all test concentrations showed that the recovery with the nominal concentration was 88.548 % (RSD was 2.121 %) at the start of the first renewal (start of the test – 0 h), 103.290 % (RSD was 13.668 %) at the end of first renewal, 82.953 % (RSD was 4.072) at the start of second renewal and 92.305 % (RSD was 7.059 %) at the end of the second renewal (end of the test - 48 hour) indicating that the results were within the acceptable limit (80 to 120 % of the nominal concentration with an RSD of <20 %). The EC50, LOEC and NOEC value for immobilization of daphnia at 24 and 48 hours are higher than 50 mg/L based on the nominal concentration of the test item.