R-AMINR

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)

Deviations:

yes

Remarks:

No analytical monitoring of test concentrations conducted

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

No analytical monitoring of test concentrations conducted

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- A 100 mg/L stock solution of the substance in dilution water was prepared by direct additions of the test substance to dilution water. This solution was used to prepare serial dilutions containing 0.1, 1 and 10 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus
- Justification for species other than prescribed by test guideline: NA
- Age at study initiation (mean and range, SD): Less than 24 hours
- Source: Culture derived from Shell Research, Sittingbourne UK
- Age of parental stock (mean and range, SD): Third brood onwards from adults aged between 14 and 42 days.
- Feeding during test: No

ACCLIMATION
- Acclimation period: Cultures are maintained for 42 days
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: The cultures were fed daily with a cocentrated suspension of Chlorella vulgaris algae at approximately 5x10^5 cells/mL. This is obtained from 5L cultures grown under semi-axenic conditions.
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): Juveniles for testing are not taken from cultures which contain adults bearing ephippia.

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: Twenty four hours before a test is setup, juveniles present in the cultures are removed and discarded. Juveniles for use in the test are then removed from the culture and transferred to fresh culture medium. The juveniles are then left for at least one hour before selecting actively swimming individuals for use. All juveniles used in the test are less than 24 hours old.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Not applicable

Post exposure observation period:

Not applicable

Hardness:

0 hours: 207 mgCaCO3/L
48 hours: 210 mgCaCO3/L

Test temperature:

0 hours: 19.7 to 19.9°C
48 hours: 19.7°C

pH:

0 hours: 7.5 to 7.9
48 hours: 8.2 to 8.3

Dissolved oxygen:

0 hours: 90 to 91 % air saturation
48 hours: 96 to 99 % air saturation

Salinity:

NA

Conductivity:

Not specified

Nominal and measured concentrations:

Nominal: 0.1, 1, 10 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Crystalline dishes
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 150 mL containing 100 mL of test medium
- Volume of solution: 100 mL
- Aeration: No
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): Four replicate dishes at 100 mg/L and and two replicate dishes at the remaining concentrations.
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): NA
- Biomass loading rate: 5 Daphnids per 100 mL.

TEST MEDIUM / WATER PARAMETERS
- The water used for culturing and testing the D.magna is reconstituted freshwater prepared by mixing treated mains water and a proprietary mineral water in the rato 1:1. The treated mains dilution water is the laboratory mains supply. The water is pumped to the laboratory via a Purite AC9 activated carbon filter and a Purite ROPF 20 particulate filter.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Not specified
- Light intensity: Not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility at 24 and 48 hours. D. Magna were considered to be immobile if, when the contents of the dish were briefly swirled, they did not swim during a 15 second period of observation.

VEHICLE CONTROL PERFORMED: No

RANGE-FINDING STUDY
- Test concentrations: NA
- Results used to determine the conditions for the definitive study: Combined range-finder and limit test conducted.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities:
- Observations on body length and weight: Not specified
- Other biological observations: Not specified
- Mortality of control: None
- Other adverse effects control: None noted
- Immobilisation of control: None
- Abnormal responses: None noted
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: All stock solutions appeared colourless and it was assumed that all the test substance was in solution.
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):

Reference substance not included

Reported statistics and error estimates:

No statistical analysis was performed as no immobility at test concentrations were observed.

Immobilisation of D.magna exposed to the substance.

Substance (mg/L)	Number of D.magna	Number immobilised
		24 h	48 h
Control	20	0	0
0.1	10	0	0
1	10	0	0
10	10	0	0
100	20	0	0

Validity criteria fulfilled:

yes

Conclusions:

At the highest tested concentration and usual limit concentration for these tests (100 mg/L), no immobility of the D.magna was observed. Therefore, the 48 hour EC50 values is > 100 mg/L (the highest concentration tested).

Description of key information

An EC/OECD method study is available assessing the potential toxicity of the substance to Daphnia magna. No effects were observed at the limit concentration in this study which provided a 48 hour EC50 value of > 100 mg/L.