5-Brom-2-[(3,4,5-trifluorphenoxy)-difluormethyl]-1,3-difluorbenzene

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

Study period:

19 Feb - 24 May 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Remarks:

reconstituted water

Details on test solutions:

Before exposure of daphnia, the test medium (reconstituted water and test material) was freshly prepared: The calibrated flask with test material and vehicle (reconstituted water) was treated in an ultrasonic device for 1 hour. Subsequently, the preparation was aerated, and stirred with an magnetic stirrer for further 23 hours. After 24 hours the formulation was given through a single use syringe filter (pore size 0.2 µm). The filtrate was used for the study.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: Institute of Toxicology, Merck KGaA
- Age: not older than 24 hours

FEEDING DURING TEST
- Food type: fresh water algae
- Frequency: once per week

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

ca. 14° dH (about 250 mg/L CaCO3)

Test temperature:

21-22 °C

pH:

control group: 7.76 - 7.82
test material group: 7.27 - 7.73

Dissolved oxygen:

control group: 87.3 - 89.9 %
test material group: 83.2 - 88.4 %

Details on test conditions:

Administration:
At the start of the experimental phase, 5 Daphnia magna were placed into test vessels with 10 mL of reconstituted water (4 vessels / control group) or test medium (4 vessels / test material group). The Daphnia magna were not fed, and the control medium and test medium were not aerated during the test.
Observation schedule:
The mortality was determined visually and recorded after 24 and 48 hours. Those animals which were not able to swim within 15 seconds after gentle agitation of the test container were considered to be immobile.
Laboratory tests:
The pH values and dissolved oxygen concentration (O2) were measured in the control and in test material medium at the beginning and at the end of the experimental part.
During the experimental part, the temperature was registered in a control vessel with an electronic therometer containing a maximum and minimum memory display.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Details on results:

A nominal dose of 100 mg/L (water solubility <0.01 mg/L revealed no aquatic toxicity in this test system. No remarkable observations were made concerning the appearance of the solution of the test material preparation. The test medium was a clear preparation and stayed unchanged throughout the study.

Under the given experimental conditions, the test material showed a 24 h and 48 h EC50 value >100 mg/L nominally.

- Mortality of control: no

Validity criteria fulfilled:

yes

Conclusions:

A nominal dose of 100 mg/L (water solubility < 0.01 mg/L) revealed no aquatic toxicity in this test system. Under the given experimental conditions, the test material showed a 24 h and 48 h EC50 value >100 mg/L nominally.

Executive summary:

The objective of this study was to determine the acute toxicity of the test material using Daphnia magna. For this purpose, juvenile Daphnia magna were exposed to an aqueous test material solution over 48 hours, under defined conditions. The study comprised of four test vessels per concentration containing five Daphnia magna each, i.e. 20 Daphnia magna per concentration (test medium group).

Daphnia magna were exposed to a nominal test material concentration of 100 mg/L (limit test) in an open static system.

Daphnia magna exposed to an aqueous preparation of the nominal concentration of 100 mg/L test item were not affected. The test material concentration in the aqueous medium was not quantified at the start and the end of this study due to the low water solubility (< 0.01 mg/L) and the fact that no toxicity was observed up to the limit of water solubility (< 0.01 mg/L). The 48 h EC50 value for Daphnia magna exceeded the maximum solubility (< 0.01 mg/L) of the test material in reconstituted water and, thus, could not be determined in this test.

Description of key information

OECD 202: 48-h EC50 > 100 mg/L (nominal)

Additional information

The objective of this study was to determine the acute toxicity of the test material using Daphnia magna. For this purpose, juvenile Daphnia magna were exposed to an aqueous test material solution over 48 hours, under defined conditions. The study comprised of four test vessels per concentration containing five Daphnia magna each, i.e. 20 Daphnia magna per concentration (test medium group).

Daphnia magna were exposed to a nominal test material concentration of 100 mg/L (limit test) in an open static system.

Daphnia magna exposed to an aqueous preparation of the nominal concentration of 100 mg/L test item were not affected. The test material concentration in the aqueous medium was not quantified at the start and the end of this study due to the low water solubility (< 0.01 mg/L) and the fact that no toxicity was observed up to the limit of water solubility (< 0.01 mg/L). The 48 h EC50 value for Daphnia magna exceeded the maximum solubility (< 0.01 mg/L) of the test material in reconstituted water and, thus, could not be determined in this test.