Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

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:
2002
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Well documented GLP study, no dose verification analysis
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes
Analytical monitoring:
no
Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: the test solutions were prepared with 100 µL acetone/L
- Controls: beside an untreated control, a solvent control was set up
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 100 µL/L in the final test solution
- Evidence of undissolved material (e.g. precipitate, surface film, etc): none
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea (Daphnia magna Straus)
- Source: Aquatic Research Organisms, Hampton New Hampshire, USA in August 2000
- Age at study initiation (mean and range, SD): less than 24 hours old
- Method of breeding: The Daphnia were cultured in media consisting of reconstituted fresh water containing live Selenastrum algal cells and YCT suspension.
- Feeding during test: not fed during the test


ACCLIMATION
- Acclimation conditions (same as test or not): similar
- Type and amount of food: Selenastrum capricornutum algal cells and YCT suspension
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Hardness:
80 mg/L as CaCO3
Test temperature:
20.1 - 20.8 °C
pH:
7.3 - 7.7
Dissolved oxygen:
4.1 to 9.2 mg/L. The 4.1 mg/L concentration was measured in the highest test concentration after 48 hours of exposure. Since 100 % immobilization was observed in this treatment level at 48 hours, the DO concentration is considered as not relevant for the immobilization. All other DO values were above 5.6 mg/L (this values was measured after 48 hours in the second highes treatment level).
Nominal and measured concentrations:
Nominal concentrations: 0 (control), 0 (solvent control), 0.5, 1.3, 3.2, 8 and 20 mg CT-737-2/L corresponding to 0, 0, 0.35, 0.91, 2.24, 5.6 and 14 mg a.i./L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): 50 mL glass beakers
- Material, size, headspace, fill volume: 50 mL fill volume
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): NA
- Biomass loading rate: NA


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted fresh water
- Alkalinity: 36 mg/L as CaCO3
-Specific conductivity: 439 µS
- Intervals of water quality measurement: at start and 48 hours


OTHER TEST CONDITIONS
- Photoperiod: 16:8 hours light dark cycle
- Light intensity: 12.7 - 13.9 micromole per square meter per second


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
EC50 at 24 and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.5
- Justification for using less concentrations than requested by guideline: NA
Reference substance (positive control):
no
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 14 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: Immobilization
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 20 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Immobilization
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
4.9 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: Immobilization
Remarks on result:
other: 95% C.I.: 3.99 - 5.95 mg a.i./L
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
7 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Immobilization
Remarks on result:
other: 95 % C.I.: 5.7 - 8.5 mg CT-737-02/L
Details on results:
- Behavioural abnormalities: After 24 hours of exposure, 5/20 daphnids were lethargic at 20 mg CT-737-02/L, after 48 hours all daphnis of this treatment level were immobilized. After 48 hours of lethargic behaviour was observed in all non-immobilized daphnids of the 8 mg CT-737-02/L treatment level.
- Mortality of control: none
- Other adverse effects control: one control daphnia was lethargic after 24 hours but normal after 48 hours.
- Abnormal responses: none
Reported statistics and error estimates:
The computer program ToxCalc was used, but the method for the calculation was not mentioned .

Table 1 Immobilization of Daphnids exposed to CT-737 -02

 Concentration [mg CT-737 -02/L]  24 hour observation # immobilized/20(Percent mortality)  24 hour observation Orientation  48 hour observation Cumulative # immobilized/20(Percent mortality) 48 hour observation Orientation 
 0 (control)  0 (0%) 1 LETH, 19 N  0 (0%) 20  N
 0 (solvent control) 0 (0%) 20 N   0 (0%) 20 N
 0.5 0 (0%) 20 N   0 (0%) 20 N
 1.3  0 (0%) 20 N   0 (0%) 20 N
 3.2  0 (0%) 20 N    0 (0%) 20 N
 8.0  0 (0%) 20 N 13 (65%) 7 LETH
 20  1 (5%)  5/20 LETH  20 (100%)  -

N: none, normal

LETH: Lethargic

Validity criteria fulfilled:
yes
Conclusions:
48-hour EC50 = 4.9 mg active ingredient/L
Executive summary:

The acute toxicity of CT-737 -02 - which contains about 70% a.i. - to Daphnia magna was determined in a static GLP test. The test was performed according to OECD 202. The test was started with a control, solvent control and nominal 0.5, 1.3, 3.2, 8.0 and 20 mg CT-737 -02/L corresponding to 0 (control), 0 (solvent control), 0.35, 0.91, 2.24, 5.6 and 14 mg a.i./L. For each test concentration and the control, 4 replicates with 5 daphinds each were set up in 50 mL vessels filled with 50 mL test solution. The test was performed in a 16:8 hour light dark cycle. Dose-verification analysis was not performed and hence, the concentrations were reported as nominal concentrations. After 48 hours of exposure, 0, 0, 0, 0, 0, 65 and 100 % of the daphnids were immobilized at 0 (control), 0 (solvent control), 0.35, 0.91, 2.24, 5.6, and 14 mg a.i./L.

The corresponding 48 h EC50 value is 4.9 mg a.i./L.

This study is considered to be acceptable for the risk assessment.

Description of key information

EC50  freshwater invertebrates = 4.9 mg a.i./ L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
4.9 mg/L

Additional information

For the data endpoint “Short-term toxicity to aquatic invertebrates” one experimental Klimisch 2 study is available.

The GLP study from Cytec (Glover 2002) was classified as Klimisch 2 study. In this study the acute toxicity of formulated product - which contains 70% a.i.- to Daphnia magna was determined in a static test. The test was performed according to guideline OECD 202. Only minor deviations were observed. The test was started with a control, solvent control nominal 0.5, 1.3, 3.2, 8 and 20 mg formulated product/L corresponding to 0 (control), 0 (solvent control), 0.35, 0.91, 2.24, 5.6 and 14 mg a.i./L. For each test concentration and the control, 4 replicates with 5 daphnids each were set up in 50 mL vessels. The test was performed in 16:8 h light dark cycle. Dose-verification analysis was not performed and hence, the concentrations were reported as nominal concentrations. After 48 hours of exposure, 0, 0, 0, 0, 0, 65 and 100 % of the daphnids were immobilized at 0 (control), 0 (solvent control),0.35, 0.91, 2.24, 5.6 and 14 mg a.i./L. The corresponding 48 h EC50 value is 4.9 mg a.i./L.

The results of this study are considered as relevant for the risk assessment and the CSA.