3'-(trifluoromethyl)acetophenone

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:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC, UV/vis-detection

Details on sampling:

- Test concentration/s : Analysis of all test item concentrations in the freshly prepared media (on 2017-07-18 and 2017-07-19) and in the media after 24 h of exposure (on 2017-07-19 and 2017-07-20) according to the semi-static conditions.
- Control at 48 hours
- Sample storage conditions before analysis: Routinely, the samples were analysed immediately. Only in exceptional cases, they were stored overnight deep frozen and protected from light.

Vehicle:

no

Details on test solutions:

PRETREATMENT OF TEST ITEM:
- A stock solution was prepared to give the desired series of test concentrations (101 mg of the test item were added to 1 litre of dilution water)
- treated for 60 seconds at 8000 rpm with an ultra turrax and stirred for 24 h on a magnetic stirrer
- To produce the different test item concentrations appropriate amounts of the stock solution were diluted with dilution water to a volume of 500 mL. 50 mL of the prepared solutions were taken per replicate and 0.5 mL of dilution water containing 5 daphnids was given to all replicates resulting in the final nominal concentrations. For each test item concentration and the control 4 replicates were prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS, parthenogenetic females
- Source: Strain of Bundesgesundheitsamt Berlin

Maintenance and acclimatisation
A population of parthenogenetic females of synchronized age structure has been maintained for more than 20 years in the test facility under constant temperature conditions (20 +/- 2 °C) at a 16 : 8 hour light-dark photoperiod (light intensity: < 20 μE x m-2 x s-1). The culture water (so-called 'M4 medium') was partly renewed once a week. The Daphnia were exclusively fed unicellular green algae (Desmodesmus subspicatus) 'ad libitum'. Mortalities of parent Daphnia during the culture period were recorded daily. The neonates were separated from their parent Daphnia by filtration prior to the acute test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

15.3 °dH (= 273 mg/L CaCO3)

Test temperature:

20.0 - 20.6 °C

pH:

7.8 - 8.0

Dissolved oxygen:

8.1 - 8.8 mg/L/

Nominal and measured concentrations:

nominal: 3.13, 6.25, 12.5, 25, 50 and 100 mg/L (nominal)
measured (geometric mean): 2.40, 4.61, 9.32, 18.01, 37.49, 73.28 mg/L
Effective concentrations ranged from 77.7 % to 86.0 % in the freshly prepared media and from 59.2 % to 73.1 % in the media after 24 hours of exposure.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers covered with watch glasses holding 5 neonates in 50 mL of test medium
- Experimental design: 6 test concentrations plus 1 control, 5 neonates per vessel, 4 replicates per concentration/control
- no feeding during the exposure period
- semi-static system
- Method of initiation: neonates were placed in prepared media
- Photoperiod: 16 h light : 8 h dark
- Temperature of incubation unit: 20.2 to 20.7°C
- Aeration: none
- Test item concentration/s: 3.13, 6.25, 12.5, 25, 50 and 100 mg/L
- Method of administration: stock solution
- Medium renewal: daily
- Duration of exposure: 48 hours
- Criteria of effects : The criterion of adverse effects used in this study was the item-induced alteration of the normal mobility behaviour and the loss of locomotory actions of the neonates, observed at 24 and 48 hours.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (so-called 'M4 medium' according to OECD 202 and EC Method C.2)

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The results are expressed in terms of geometric mean measured concentrations.
Effective concentrations ranged from 77.7 % to 86.0 % in the freshly prepared media and from 59.2 % to 73.1 % in the media after 24 hours of exposure.

Reported statistics and error estimates:

The EC 50 was calculated by probit analysis using the statistics programme ToxRatPro Version 2.10 (released 2010-09-10).

Validity criteria fulfilled:

yes

Remarks:

immobilisation and other abnormalities in the controls did not exceed 10 % by the end of the test; dissolved oxygen concentration remained above 3 mg/L throughout the exposure period

Conclusions:

The 48h-EC50 of the test substance under exposure conditions was determined as 10.7 mg/L towards daphnids.

Executive summary:

A study was performed to assess the acute toxicity of Trifloxystrobin-TFMAP to Daphnia magna STRAUS under semi-static conditions in accordance with the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004).

A range finding test preceded the main test. It provided information about the range of concentrations which were used in the main test. The following nominal concentrations of the test item were tested in the range finding test: 1, 10 and 100 mg/L.

In the main test Daphnia were exposed to a range of concentrations, nominally 3.13, 6.25, 12.5, 25, 50 and 100 mg/L of Trifloxystrobin-TFMAP dissolved in dilution water. Auxiliaries used to prepare the test media were an ultra turrax, a magnetic stirrer and folded filters. The test was conducted as a semi-static test with daily renewal of test medium.

During the test a temperature range of 18 - 22 °C was maintained in the test vessels, with a maximum temperature fluctuation of +/- 1 °C in each individual test. The temperature, the pH and the oxygen values were measured every day in the freshly prepared media and in the media after 24 hours of exposure.

Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The following value was determined 48 h-EC50: 10.7 mg/L.

The results are expressed in terms of geometric mean measured concentrations.

Effective concentrations ranged from 77.7 % to 86.0 % in the freshly prepared media and from 59.2 % to 73.1 % in the media after 24 hours of exposure.

Description of key information

A study was performed to assess the acute toxicity of Trifloxystrobin-TFMAP to Daphnia magna STRAUS under semi-static conditions in accordance with the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004).

A range finding test preceded the main test. It provided information about the range of concentrations which were used in the main test. The following nominal concentrations of the test item were tested in the range finding test: 1, 10 and 100 mg/L.

In the main test Daphnia were exposed to a range of concentrations, nominally 3.13, 6.25, 12.5, 25, 50 and 100 mg/L of Trifloxystrobin-TFMAP dissolved in dilution water. Auxiliaries used to prepare the test media were an ultra turrax, a magnetic stirrer and folded filters. The test was conducted as a semi-static test with daily renewal of test medium.

During the test a temperature range of 18 - 22 °C was maintained in the test vessels, with a maximum temperature fluctuation of +/- 1 °C in each individual test. The temperature, the pH and the oxygen values were measured every day in the freshly prepared media and in the media after 24 hours of exposure.

Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The following value was determined 48 h-EC50: 10.7 mg/L.

The results are expressed in terms of geometric mean measured concentrations.

Effective concentrations ranged from 77.7 % to 86.0 % in the freshly prepared media and from 59.2 % to 73.1 % in the media after 24 hours of exposure.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

10.7 mg/L