Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1997
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): RA 3643
- Substance type: white powder
- Physical state: solid
- Lot/batch No.: 87/96
- Stability under test conditions: stable
- Storage condition of test material: room temperature

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Dimethylsulfoxide (DMSO)
- Concentration of vehicle in test medium (stock solution and final test solution):0.1 ml DMSO.l^-1

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Every week a number of cultures is started with ca. 125 dalphnias of the same age (about one day) in ca. 4 litres of dilution water. The cultures are fed daily with ca. 4x10^9 algal cells (chlorella) and ca. 0.13 grams of yeast per 4 litre. The medium is completely replaced at least once a week; at the same time all young born are removed. The cultures are kept at 20+/-1°C under a 16h light and 8h dark regime with trensition periods of ca. 30 minutes. After 4 weeks the cultures are discarded.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
202 mg/l
Test temperature:
The temperature in one of the control vessels was measured at the beginning and at the end of the test. The temperature in the test vessels was 19.9 at the beginning and 20.6 °C at the end of the test.
pH:
The pH concentration was measured at the beginning and at the end of the test. pH concentration was also measured after 24h in all test media, in which all animals were immobile. The pH vared between 8.0 and 8.3.
Dissolved oxygen:
The oxygen concentration was measured at the beginning and at the end of the test. Oxygen concentration was also measured after 24h in all test media, in which all animals were immobile. The lowest value measured was 8.2 mg/l.
Details on test conditions:
The test was carried out under a 16h light- 8h dark regime with transition periods of ca. 30 minutes in a temperature controlled room.
Reference substance (positive control):
yes
Remarks:
DMSO

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Remarks:
mobility
Effect conc.:
> 10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Duration:
48 h
Dose descriptor:
NOEC
Remarks:
mobility
Effect conc.:
>= 1.88 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Duration:
48 h
Dose descriptor:
EC50
Remarks:
mobility
Effect conc.:
> 1.88 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Duration:
48 h
Dose descriptor:
NOEC
Remarks:
mobility
Effect conc.:
>= 10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.

Applicant's summary and conclusion

Conclusions:
After 48h a few daphnias were dead at dosed amounts of 3.2, 5.6 an 10 mg.l^-1. This mortality (10% or less) can most likely be attributed to the presence of un dissolved material, causing physical hampering of the test organisms. Indications for this phenomenon were obtained in the range finding test, although this could not be visually assessed in the final test. Furthermore, because 10% immobility (in the control) is allowed according to the OECD guidiline no. 202, this mortality is not taken into account to estimate the NOEC value.
It is concluded that RA 3643 is not acutely toxic to Daphnia magna, with respect to mobility and condition, when exposed at its aquaeous solubility level.