2-(1,3-dioxoisoindolin-2-yl)ethane-1-sulfonamide

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:

201-08-14 to 2018-10-15

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:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC-DAD

Details on sampling:

- Concentrations: 200 mg/L (nominal) and 0 mg/L
- Sampling method: At the start of the exposure and at renewal (0 and 24 h), samples of the fresh media were taken after preparation of the limit concentration and analyzed. At renewal and at the end of the exposure (24 and 48 hours), samples of the 24-hours old media were taken directly from the test vessels and analyzed.
- Sample storage conditions before analysis: If necessary, all original samples were stored at room temperature before preparation. Prepared samples were stored in an autosampler at room temperature until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A limit concentration of 200 mg/L of the test item was prepared with dilution water prior to the start of the exposure (at day 0) and prior to the renewal of the test solution (at day 1). The test item solution was treated with ultrasound for 5 min at room temperature and stirred thereafter for 1 h with a magnetic stirrer at approximately 1100 rpm at room temperature. As a Tyndall effect was still visible, the stirring period was prolonged to 2 h. Since the Tyndall effect was still present, the solution was treated with ultrasound at room temperature for another 10 min. After that, only a slight Tyndall effect was visible.
- Controls: Dilution water without test item incubated under the same conditions as the test groups.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna STRAUS
- Age of parental stock (mean and range, SD): Less than 24 hours old daphnids from a healthy stock were used for the study. Juvenile daphnids were removed from the culture vessels at the latest 24 hours before the start of the exposure and discarded. The juveniles born within the following period of max. 24 hours preceding the exposure were used for the test. No first brood progeny was used for the test.

ACCLIMATION
- Acclimation period: Acclimatization of the daphnids was not necessary, because the composition of the dilution water was equivalent to the culture medium.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

259-263 mg CaCO3/L

Test temperature:

20.0 °C ± 1°C

pH:

7.38-7.48

Dissolved oxygen:

7.68-8.33 mg/L

Nominal and measured concentrations:

200 mg/L and 0 mg/L nominal
148 mg/L and < LOQ measured

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): loosely covered with glasses
- Material, size, headspace, fill volume: 50 mL capacity, glass, fill volume 20 mL
- Renewal rate of test solution (frequency/flow rate): renewal at 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates):4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Culture Medium Elendt M4 according to OECD 202
pH: 8.2 ± 0.8
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: Diffuse light, light intensity of max. 1500 lx

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 0, 1.0, 10.0, 100 mg/L
- Results used to determine the conditions for the definitive study: No immobilisation was found at the concentrations tested.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

148 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 148 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.:

> 148 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 148 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Other biological observations: none
- Mortality of control: none
- Other adverse effects control: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: a slight Tyndal effect was observed at the concentration tested.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels:
- ECx: EC50: 2.03 mg/L CI (1.17-3.57 mg/L), validity range: 0.6 - 2.4 mg/L, acc. to AQS P 9/2 (02/2000); clone 5 0.6 - 2.1 mg/L, acc. to OECD 202 (2004); clone A

- Other:

Reported statistics and error estimates:

The effects of the limit concentration were deduced directly from the observed immobilization rates. The effect levels (EC10 / 50 / 100) are given based on the analytically confirmed nominal concentrations. An EC50-value and confidence intervals were calculated for the reference item by linear dose-response regression with the software GraphPad Prism.

The validity criteria were fulfilled:

In the control group, no daphnids were immobilized or showed any signs of disease or stress, e.g. discoloration or unusual behavior such as trapping on the surface of the water, during the 48-hour test period (required: not more than 10% of the daphnids immobilized in the control). The dissolved O2concentration in the 24-hours old media was ≥ 7.68 mg/L (required: ≥ 3 mg/L in the 24-hours old media) in the limit concentration and in the control.

Table 1: Measured Concentrations and Percent of Nominal Concentration of the Test Item 2-Phthalimidoethanesulfonamide (TA-3) during the Definitive Test

Sampling date	0 hours Fresh medium		24 hours Old medium		24 hours Fresh medium		48 hours Old medium		Geometric mean meas. conc. [mg/L]
Nominal concentration of the	2‑Phthalimidoethanesulfonamide(TA-3)
test item [mg/L]	Meas. conc. [mg/L]	%	Meas. conc. [mg/L]	%	Meas. conc. [mg/L]	%	Meas. conc. [mg/L]	%
200	181	91	118	59	181	90	124	62	148
Control	< LOQ		< LOQ		< LOQ		< LOQ

Validity criteria fulfilled:

yes

Conclusions:

In the limit concentration of 148 mg/L (based on geometric mean measured concentrations corresponding to a nominal concentration of 200 mg/L) of the test item 2-Phthalimidoethanesulfonamide (TA-3), no effects on Daphnia magna were observed.

Description of key information

In  the  acute  immobilization  test  with  Daphnia  magna  (STRAUS),  the  effects  of 2-Phthalimidoethanesulfonamide (TA-3) were determined according to OECD 202 (2004). The validity criteria of the test guidelines were fulfilled. In the limit concentration of 148 mg/L (based on geometric mean measured concentrations corresponding to a nominal concentration of 200 mg/L) of the test item 2-Phthalimidoethanesulfonamide (TA-3), no effects on Daphnia magna were observed.