(2-hydroxyethyl)ammonium mercaptoacetate

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:

from 12/07/07 to 16/01/08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. certificate)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not relevant

Analytical monitoring:

yes

Details on sampling:

- Sample storage conditions before analysis: 4°C in the dark

Vehicle:

no

Details on test solutions:

Amounts of test material (1.08, 1.94, 3.44, 6.02 and 10.76g) were each seperatly dissolved in degassed reverse osmosis water and the volume
adjusted to 20 ml to give 1.08, 1.94, 3.44, 6.02 and 10.76 g test material/20 ml stock solutions respectively.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Age at study initiation: < 48 hours.

ACCLIMATION
- Acclimation conditions: maintained in polypropylene vessels containing approximately 2 litres of reconstituted water in a temperature controlled room at 19.8°C to 20.7°C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods.
- Feeding: daily with a suspension of algae (Chlorella sp.).

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg/l as CaCO3

Test temperature:

20 °C

pH:

7.8

Dissolved oxygen:

air saturation value

Salinity:

no data

Nominal and measured concentrations:

Nominal concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 ml glass jars containing approximately 200 ml of test preparation
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration: 4
- 2 replicates of 10 animals for the control.
- Renewal of the solution: not renewed during the exposure period as pre-test stability analyses indicated the test material to be stable under test conditions for the duration of the test.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: An aliquot (25 ml) of each of solutions a-d was added to each litre (final volume) of deionised water with a conductivity of <5 μS cm-1. The reconstituted water had a pH of 7.8 ± 0.2 adjusted (if necessary) with NaOH or HCl and was aerated until the dissolved oxygen concentration was approximately air-saturation value.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods.
- No food during exposure.

TEST CONCENTRATIONS
- Range finding study:
- Test concentrations: nominal test concentrations of 0.10, 1.0, 10 and 100 mg ai/l.
- Results used to determine the conditions for the definitive study: After 24 and 48 hours the number of immobilised Daphnia magna were recorded.

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 49 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

The test material preparations were observed to be clear, colourless solutions throughout the duration of the test.
Temperature was maintained at approximately 20°C throughout the test, while there were no treatment related differences for oxygen concentration or pH.

Results with reference substance (positive control):

no data

Validity criteria fulfilled:

yes

Remarks:

see conclusions

Conclusions:

The study was performed in compliance with its quality criteria:
- Test daphnids in the control were not trapped at the surface of the water.
- Concentration of dissolved oxygen in the test vessel remained above 2 mg/L at end of the test and pH did not vary by more than 1 unit.
- No more than 10 % of the daphnids immobilized in the control at the end of the test.
- Concentrations of the test substance were maintained to within 80 % of the initial concentrations throughout the duration of the test.

Executive summary:

Acute toxicity of Monoethanoamine thioglycolate to Daphnia magna has been investigated through a test in accordance with OECD Guideline 202 and GLP requirements.

Daphnia magna were exposed for 48 hours to an aqueous solution of Monethanolamine thioglycolate at a nominal concentrations

of 10, 18, 32, 56 and 100 mg ai/L.

EC 50 - 48h determined was 49 mg ai/L and NOEC was of 18 mg ai/L.

The study was performed in compliance with its quality criteria.

Description of key information

Acute toxicity of the thioglycolate anion to Daphnia magna has been investigated through two tests in accordance with OECD TG 202 and GLP requirements. One test was conducted with MeaTG and the other with thioglycolic acid itself. The lower EC50 value was choosen as the key value for chemical safety assessment.
Daphnia magna were exposed for 48 hours to an aqueous thioglycolate solution at a nominal concentrations
of 10, 18, 32, 56 and 100 mg ai/L.
EC 50 - 48h determined was 49 mg ai/L and NOEC was of 18 mg ai/L.

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:

38 mg/L