Glycine, N-methyl-, N-coco acyl derivs.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A defined amount of the test substance (stock solution concentration = 500 mg/L) was weighed into a measuring flask and the total volume was filled up with dilution water. The test bottles were conditioned about 15 min before the test was started.
- Differential loading: yes
- Controls: yes, dilution water served as negative control
- Evidence of undissolved material: the test item is soluble in water at pH 7

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Umwelt-Bundesamt, Berlin, Germany
- Feeding during test: no
- Age of daphnia at study initiation: 6 - 24 h

BREEDING
- Breeding conditions (same as test or not): illumination diffuse, full time
- Type and amount of food: freshwater-alga-suspension (Scenedesmus subspicatus)
- Feeding frequency: daily

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.9 °C

pH:

before test: 7.4 (control), 7.5 - 7.7 (test solutions)
after test: 7.5 (control), 7.5 - 7.6 (test solutions)

Dissolved oxygen:

before test: 5.8 mg/L (control), 5.2 - 5.5 mg/L (test solutions)
after test: 5.9 mg/L (control), 5.3 - 5.7 mg/L (test solutions), corresponding to 66% of the air saturation

Nominal and measured concentrations:

nominal: control, 1.0, 2.5, 5.0, 10 and 20 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Test solution volume: 10 mL
- 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: distilled water
- Ca/mg ratio: 4:1, sum = 2.5 mmol/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: 24 h. The pH-value and O2 concentration were measured before and after the test

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: no light, the test was performed in the dark

EFFECT PARAMETERS MEASURED:
- immobility: at 24 h and at the end of the test at 48 h

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

5.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

2.91 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: 0%

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 (24 h) = 1.2 mg/L

Reported statistics and error estimates:

A probit analysis was performed on the experimental data using the computer program "Dosis 50". Since no probit values are defined for the experimentally determined values of 0% and 100% mortality, the probit values for 1% and 99%, respectively, were used.

The highest tested concentration of test substance producing no immobile daphnia under test conditions after 48 h was 2.5 mg/L.

The lowest tested concentration of test substance producing 100% immobile daphnia under test conditions after 48 h was 20 mg/L.

Table 1. Study results.

Concentration of test substance [mg/L]	Immobilization [%]		pH-value		O2 [mg/L]
	24 h	48 h	Before test	After test	Before test	After test
20	100	100	7.5	7.5	5.5	5.3
10	70	95	7.6	7.5	5.3	5.7
5.0	45	50	7.7	7.6	5.3	5.7
2.5	0	0	7.7	7,6	5.2	5.7
1.0	0	0	7.7	7.6	5.3	5.6
control	0	0	7.4	7.5	5.8	5.9

Validity criteria fulfilled:

yes

Description of key information

EC50 (48 h) = 5.2 mg/L (nominal, Daphnia magna, OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

5.2 mg/L

Additional information

One GLP-study according to OECD 202 investigating the short-term toxicity of Glycine, N-methyl-, N-coco acyl derivatives (CAS 68411-97-2) to aquatic invertebrates is available. The test organism Daphnia magna was exposed to five nominal test concentrations ranging from 1.0 - 20.0 mg/L (1.0, 2.5, 5.0, 10 and 20 mg/L) in controlled conditions for 48 h. No analytical measurement was conducted. The number of immobilised test individuals was recorded every 24 h and compared to the negative control. After 48 h immobilisation was observed at concentrations ≥ 5.0 mg/L. The derived nominal EC50 after 48 h was 5.2 mg/L (nominal).