2-morpholinoethanesulphonic acid

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:

2017-01-30 to 2017-12-21

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 13th April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

May 30, 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 108 mg/L

- Sampling method: For determination of the test item concentration, four replicate samples were taken from the test item treatment group and one from the control at the start and at the end of the experiment. The analysis was performed using LC/MS/MS applying MRM (multiple reaction monitoring) assay.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test solution used in the test was prepared by mechanical dispersion. An amount of 0.0432 g test item was dissolved in 400 mL dilution water (ISO medium) in order to obtain the concentration of 108 mg/L. The test solution was freshly prepared in the testing laboratory just before introduction of test animals (start of the experiment).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus
- Source: Laboratory of Hydrobiology, 2100 Gödöllö, Kotlan S. u. 3, Hungary

ACCLIMATION
Test animals were bred under similar (or the same) conditions as that used during the exposure period (holding water, temperature, background colour etc.), therefore additional acclimatization before the test was not necessary. Brood daphnids were maintained in dilution water at the test temperature for at least 48 hours prior to the start of the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

249 mg/L (as CaCO3)

Test temperature:

19.4 - 19.6 °C

pH:

6.66 - 7.37

Dissolved oxygen:

8.66 - 9.47 mg/L

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

Nominal conc.: 108 mg/L
Measured conc.: Concentrations reported as nominal as recovery was 100 - 104%

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beaker
- Type: open
- Material, size, fill volume: glass, 50 mL, 40 mL
- Aeration: none
- 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: reconstituted water (ISO medium acc. to OECD TG 202)

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16/8 (light/dark)

EFFECT PARAMETERS MEASURED: immobilisation after 24 and 48-h

RANGE-FINDING STUDY
- Test concentrations: 0.01 - 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There was no immobilisation observed in the control and in the 108 mg/L concentration group. In both groups no abnormal behaviour or appearance of test animals was noted.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: The 24-h EC50: 1.57 mg/L (95 % confidence limits: 1.31 – 1.79 mg/L)
- Limit test: no
- Dose-response test: yes

Validity of the Study

Immobilisation was not observed in the control group and the dissolved oxygen concentration at the end of the test in control and test vessels was more than 3 mg/L in all cases. All validity criteria were within acceptable limits and therefore the study was considered as valid.

 

Analytical Results

The test item was not detected in the untreated control group. In the treated group mean measured concentrations of the test item were 104 % of the nominal at the start and 100 % at the end of the test. Since the measured test item concentration remained within ± 20 % of the nominal during the test period of 48 hours, the biological results are given at nominal concentration.

 

Table 1: Summary of the Biological Endpoints

Parameter	Concentration [mg/L] based on nominal concentration
48 h-EC50 95 % conf. limits	> 108 not calculated
48 h-NOEC	108
48 h-LOEC	> 108

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the 48-h NOEC was determined to be 108 mg/L and the LOEC and the EC50 values were determined to be > 108 mg/L.

Executive summary:

The aquatic toxicity of the test item was assessed using Daphnia magna in a 48-h Acute Immobilisation Test according to OECD TG 202 and under GLP. For this purpose, young Daphnia were exposed to aqueous test media containing the test item for 48 hours. Based on results obtained in a non-GLP preliminary experiment Daphnia were exposed to a single concentration of 108 mg/L (limit concentration). Potassium dichromate served as the reference control. A static test was performed as the test item was previously shown to be stable in the test medium for 72-h. The purpose of the analytical part of this study was to verify the concentration of the test item in the test medium. The analytically measured test item concentration remained within ± 20 % of the nominal during the test period of 48-h; therefore, biological results are based on the nominal concentration. Healthy, young female daphnids with known origin, history and acclimatization conditions were used. The test item and the control were tested using 20 Daphnia (divided into 4 concurrent subgroups) each. Each test vessel contained approximately 40 mL test medium. Fully characterized (content, physicochemical characteristics) ISO Medium was used as test medium. The immobilisation of the test animals was recorded 24 and 48-h after treatment. Environmental conditions were recorded. All measured values remained within acceptable ranges. All validity criteria were met and therefore the study was considered as valid. The 48-h NOEC was determined to be 108 mg/L and the LOEC and the EC₅₀ values were determined to be > 108 mg/L.

Description of key information

Under the test conditions, the 48-h NOEC was determined to be 108 mg/L and the LOEC and the EC₅₀ values were determined to be > 108 mg/L (reference 6.1.3-1).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

108 mg/L

Additional information

The aquatic toxicity of the test item was assessed using Daphnia magna in a 48-h Acute Immobilisation Test according to OECD TG 202 and under GLP. For this purpose, young Daphnia were exposed to aqueous test media containing the test item for 48 hours. Based on results obtained in a non-GLP preliminary experiment Daphnia were exposed to a single concentration of 108 mg/L (limit concentration). Potassium dichromate served as the reference control. A static test was performed as the test item was previously shown to be stable in the test medium for 72-h. The purpose of the analytical part of this study was to verify the concentration of the test item in the test medium. The analytically measured test item concentration remained within ± 20 % of the nominal during the test period of 48-h; therefore, biological results are based on the nominal concentration. Healthy, young female daphnids with known origin, history and acclimatization conditions were used. The test item and the control were tested using 20 Daphnia (divided into 4 concurrent subgroups) each. Each test vessel contained approximately 40 mL test medium. Fully characterized (content, physicochemical characteristics) ISO Medium was used as test medium. The immobilisation of the test animals was recorded 24 and 48-h after treatment. Environmental conditions were recorded. All measured values remained within acceptable ranges. All validity criteria were met and therefore the study was considered as valid. The 48-h NOEC was determined to be 108 mg/L and the LOEC and the EC₅₀ values were determined to be > 108 mg/L.