1,2-Benzisothiazole, 3-methyl-, 1,1-dioxide

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:

2016-11-16 to 2016-11-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

31 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

April 1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Lot: 216-106
- Expiry date: 2018-06-16
- Storage conditions: Keep at room temperature

Analytical monitoring:

yes

Details on sampling:

- Concentrations: each test concentration and control
- Sampling method: from the test solutions (10 mL at the start, before distribution of the test solution to the vessels and 4 x 2 mL at the end of the study)

Vehicle:

yes

Remarks:

ISO medium

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
In order to prepare the test solutions, a saturated stock solution was first prepared as follows:
A stock solution of 100 mg/L (nominal concentration) was first prepared by dissolving the test item in ISO medium, thereafter sonicated for 30 minutes in ultrasonic bath (under cooling). The test solutions of subsequent lower concentrations were prepared by appropriate dilution of this stock solution.
The test solutions were prepared immediately before introduction of daphnids.

- Controls: Untreated Control: The dilution water (ISO-medium) was used without addition of the test item.; Toxic Reference Control: Potassium dichromate
- Chemical name of vehicle: ISO medium
- Concentration of vehicle in test medium: not applicable as the ISO medium was used for substance dilution

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Daphnia magna (Straus)
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age of parental stock: Less than 24 hours old
- Feeding during test: No.
- Food type: centrifuged green alga suspension during breeding

ACCLIMATION
- Acclimation period: Test animals were bred under similar conditions as that used during the exposure period, therefore additional acclimatisation before the test was not necessary.
- Type of food: centrifuged green alga suspension during breeding

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

ISO medium: 249 mg/L (as CaCO3, theoretical)

Test temperature:

Test vessels: 20.1 – 20.3 °C
Ambient temperature: 19.8 – 20.7 °C

pH:

6.98 – 8.09

Dissolved oxygen:

7.50 – 8.32 mg/L

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 6.25, 12.5, 25, 50 and 100 mg/L

Mean of the measured concentrations (mg/L)
Start of experiment (n=4): 6.69, 13.5, 28.0, 54.5, 105.3
End of experiment (n=4): 6.58, 13.6, 26.8, 54.5, 104.1
The analytically determined concentrations of the tested substance were maintained within ± 20 % of the nominal concentrations throughout the test. Therefore the analysis of the results was based on the nominal concentration values.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers of approximately 40 mL test medium
- 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: Separate stock solutions of individual substances were first prepared in deionised water (MILLIPORE ELIX 3 water purification system). The ISO medium was prepared by adding 25 mL from each of four stock solutions to one litre deionised water.
- The ISO medium was prepared according to OECD 202 and used as dilution water.

OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: The light-dark cycle during the test was 16 hours light (artificial illumination) and 8 hours darkness.

EFFECT PARAMETERS MEASURED
The immobility or mortality of the Daphnia was determined by visual observation after 24 and 48 hours of exposure. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker were considered to be immobile.

VEHICLE CONTROL PERFORMED: not applicable as the ISO medium was used for substance dilution

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10, 50, 100 % v/v saturated solution (stock solution of 100 mg/L)
- Results used to determine the conditions for the definitive study: 3 animals of 10 were immobilised using 100 % (48 h). No other mortality was detected.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, not run in parallel but twice per year to evaluate test conditions

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Behavioural abnormalities: No abnormal behaviour of test animals was observed in the control and in the concentrations of 6.25, 12.5, 25 and 50 mg/L after 48 hours of exposure. At the test concentration of 100 mg/L a 15 % (not significant) immobilisation was detected.
- Observations on body length and weight: No body weight and length was determined.
- Other biological observations: No.
- Mortality of control: No.
- Other adverse effects control: No immobilisation was observed for control animals. No Daphnia were trapped at the water surface or showed any sign of stress.
- Abnormal responses: No.
- Any observations that might cause a difference between measured and nominal values: No.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

Experiments with Potassium dichromate were not run in parallel but twice per year to evaluate test conditions. No details were provided from those tests.

Reported statistics and error estimates:

No significant toxic effects on the mobility of Daphnia were reported.

Validity criteria fulfilled:

yes

Conclusions:

An EC50 > 100 mg/L (48 h) was determined with a short-term toxicity test in daphnia.

Executive summary:

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202. The study was conducted under static conditions over a period of 48 h with concentrations of 6.25, 12.5, 25, 50 and 100 mg/L (nominal concentrations). Twenty Daphnids were exposed to each concentration level and the control. The measured concentration of the test item in the test solution was in the range of 105 – 112 % of the nominal values at the start and 104 – 109 % of the nominal values at the end of the test. There is evidence that the concentration of the tested substance was maintained within ± 20 % of the nominal concentration throughout the test. Therefore the analysis of the results was based on the nominal concentration values. No immobilisation or any abnormal behaviour of test animals was observed in the control and in the concentrations of 6.25, 12.5, 25 and 50 mg/L after 48 hours of exposure. At the test concentration of 100 mg/L a 15 % immobilisation was detected. No significant immobilisation was observed in any of the test concentrations of the test item during the 48-hour exposure of the test (Fisher’s Exact Test). The EC10, EC50 and EC100 values were derived for 48 h to be > 100 mg/L. The NOEC of 100 mg/L (48 h) was determined for daphnia based on nominal concentration.

Description of key information

An EC50 > 100 mg/L (48 h) was determined with a short-term toxicity test with daphnia.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202. The study was conducted under static conditions over a period of 48 h with concentrations of 6.25, 12.5, 25, 50 and 100 mg/L (nominal concentrations). Twenty Daphnids were exposed to each concentration level and the control. The measured concentration of the test item in the test solution was in the range of 105 – 112 % of the nominal values at the start and 104 – 109 % of the nominal values at the end of the test. There is evidence that the concentration of the tested substance was maintained within ± 20 % of the nominal concentration throughout the test. Therefore the analysis of the results was based on the nominal concentration values. No immobilisation or any abnormal behaviour of test animals was observed in the control and in the concentrations of 6.25, 12.5, 25 and 50 mg/L after 48 hours of exposure. At the test concentration of 100 mg/L a 15 % immobilisation was detected. No significant immobilisation was observed in any of the test concentrations of the test item during the 48-hour exposure of the test (Fisher’s Exact Test). The EC10, EC50 and EC100 values were derived for 48 h to be > 100 mg/L. The NOEC of 100 mg/L (48 h) was determined for daphnia based on nominal concentration.