2-Butenoic acid, 4,4,4-trifluoro-3-(methylamino)-, ethyl ester, (2Z)-

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

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

ethyl (2Z)-4,4,4-trifluoro-3-(methylamino)but-2-enoate

EC Number:

801-277-8

Cas Number:

507448-65-9

Molecular formula:

C7H10F3NO2

IUPAC Name:

ethyl (2Z)-4,4,4-trifluoro-3-(methylamino)but-2-enoate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Water samples of each concentration (2 x 100 m volume each) were taken from the freshly prepared test solutions at the start of exposure.

At test termination (48 hours) 2 samples of 50 ml and 2 samples of 100 ml were taken from all 4 replicates of each concentration.

All samples were kept at -18 °C to -22 ° C until analysis.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

The specimens were thawed in a microwave oven at ambient temperature. After intensively shaking, the measured specimens were diluted with methanol in the ratio 1:1. The final volume was measured to calculate the dilution factor. These solutions were filtered through a 0.45 µm filter before injection.

24.6 – 66.8 mg CA 2245 A were weighed, dissolved and made up to 25.0 ml with methanol. From these stock solutions, reference solutions in the range of the test concentrations (related to and extended to about 10 % below and above the expected concentration) were diluted with methanol/test water = 1/1 (v/v). So references with concentrations between 0.20 – 13.36 mg/L CA 2455 A were used.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Species: Daphnia magna STRAUS 1820
- Strain: Clone 5
- Source: In-house
- Age at study initiation: < 24 hours

Study design

Test type:

static

Total exposure duration:

48 h

Test conditions

Hardness:

Water hardness corrsponded to 260 and 240 mg CaCO3/L (2 bottles).

Test temperature:

21 ± 1 °C

pH:

8.5 and 8.0 – 8.1 at the start and at the end of exposure, respectively.

Dissolved oxygen:

100 -104 % and 92 – 95 % at the start and at the end of exposure, respectively.

Salinity:

Conductivity was measured to be 642 and 663 µS (2 bottles)

Nominal and measured concentrations:

Nominal Concentrations: 0.50, 1.0, 2.0, 4.0, 8.0 and 16.0mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 ml glass beakerss containing 100 ml of test solution or blank test medium
- No. of animals per concentration: 20 animals for each concentration and the control
- No. of organisms per vessel: 5 animals exposed per test vessel and the control
- No. of vessels per concentration: 4 test vessels for each concentration
- No. of vessels per control: 4 test vessels for the control


TEST MEDIUM / WATER PARAMETERS
- Test medium: M4- medium according to ELENDT.

OTHER TEST CONDITIONS
- Photoperiod: Light-dark cycle of 16 hours light and 8 hours datk with a 30 minutes transition period.
- Light intensity: Fluorescent light (approx. 1100 lux).

EFFECT PARAMETERS MEASURED
- Oxygen content: At start and test end (48 hours).
- pH: At start and test end (48 hours).
- Temperature: At start and test end (48 hours).
- Hardness: From the freshly prepared M4-medium.
- Conductivity: From the freshly prepared M4-medium.

TEST CONCENTRATIONS
- Test concentrations: Nominal 0.50, 1.0, 2.0, 4.0, 8.0 and 16.0mg/L

BIOLOGICAL OBSERVATIONS
- Observation intervals: Immobilization and other behavioural changes of the daphnids were recorded after 24 and 48 hours of
exposure.
Those animals not able to swim within 15 seconds after gentle agitation of the test container were
considered to be immobile.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

ca. 8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 6.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL

Details on results:

- Test concentrations: The measured test concentrations of CA 2455 A were 0.38, 0.74, 1.6, 3.1, 5.9 mg/L and LOD
(limit of detection, test item was not homogeneously distributed at the highest concentration)
at the start of exposure and (test item is not hydrolytical stable).

- Other observations: Despite the fact, that the test item is not miscible with water, the initial recovery directly after
application was between 70 and 80 % of nominal concentration (except the highest concentration).

The solubility of the test item and its physical characteristics did not allow to achieve the nominal test
concentrations over the whole test period.

- Other biological observations: No immobilization of daphnids was observed in the controls and at test concentrations of 0.50, 1.0
and 2.0 mg/L. After exposure for 48 hours 24, 60 and 95 % of daphnids were immobilized at test
concentrations of 4.0, 8.0 and 16.0 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC 50 (48h) of CA 2455 A was determined to be 6.5 mg/L based on nominal concentrations.
The highest concentration with no observed effects after 48 hours was 2.0 mg/L based on nominal concentrations of CA 2455 A.

Executive summary:

 

Test concentrations of nominal 0.50, 1.0, 2.0, 4.0, 8.0 and 16.0mg/L of CA 2455 A were selected based on results of a range-finding test and a preliminary test. Exposure started when the daphnids were placed in the test vessel containing the test solutions. 

Twenty daphnids were exposed to each of the desired test concentrations under static conditions in M4-medium. For the test concentrations and the control, four replicates were performed. Each replicate consisted of five specimens in 100ml test solution. The daphnids were observed for immobilization and behavioural changes after 24 h and 48 h of exposure. 

The water temperature was maintained constant throughout the duration of the test at 21±1 °C in all test concentrations. The oxygen saturation was measured to be 100 -104 % and 92 – 95 % at the start and at the end of exposure, respectively. The pH was 8.5 and 8.0 – 8.1 at the start and at the end of exposure, respectively. 

The measured test concentrations of CA 2455 A were 0.38, 0.74, 1.6, 3.1, 5.9 mg/L and LOD (limit of detection, test item was not homogeneously distributed at the highest concentration) at the start of exposure and <LOQ, 0.05, 0.16, 0.27 and 1.7 mg test item/L at the end of exposure (test item is not hydrolytical stable).

Despite the fact, that the test item is not miscible with water, the initial recovery directly after application was between 70 and 80 % of nominal concentration (except the highest concentration). 

No immobilization of daphnids was observed in the controls and at test concentrations of 0.50, 1.0 and 2.0 mg/L. After exposure for 48 hours 24, 60 and 95 % of daphnids were immobilized at test concentrations of 4.0, 8.0 and 16.0 mg/L. 

Following values are based on nominal concentrations.

 

Exposure period	EC 50	95 % confidence limit	Slope	No effect level (observed)
Hours	mg/L	mg/L		mg/L
24 48	8.0 6.5	6.5 – 10.2 5.3 – 8.1	1.71 1.78	2.0 2.0

 

Conclusion:

The EC 50 (48h) of CA 2455 A was determined to be 6.5 mg/L based on nominal concentrations. 

The highest concentration with no observed effects after 48 hours was 2.0 mg/L based on nominal concentrations of CA 2455 A.