2-Pyridinecarboxamide, 4-(4-aminophenoxy)-N-methyl-

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:

7/2004

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

Details on sampling:

Aliquots of the samples from the biological test were directly analysed by HPLC and UV/VIS-detection (range of the injection volume: 1-100 µL, depending an the expected concentration).
- Concentrations: at 0 and 48 hours, Control at 48hours
- Sampling method: from freshly prepared medium
- Sample storage conditions before analysis: The biological test solutions were routinely measured on the day of sampling. If this was exceptionally not possible, the samples were stored in a refrigerator until the analysis was carried out.

sampling schedule:
control: 0 and 48 h
test concentrations: 0 and 48 h

Vehicle:

no

Details on test solutions:

PRETREATMENT OF TEST ITEM:
- 59.9 mg of the test item were added to 1 l of dilution water
- treated with an ultrasonic bath, stirred for 24 hours on a magnetic stirrer

Test organisms (species):

Daphnia magna

Details on test organisms:

- Daphnia magna STRAUS, parthenogenetic females, strain of the Federal Health Office (BGA), Berlin Germany
Maintenance and Acclimatisation:
A population of parthenogenetic females of synchronized age structure has been maintained for more than 15 years in the test facility under constant temperature conditions (20 +/- 1 °C) at a 16 : 8 hour light-dark photoperiod (illumination: < 1000 lux). 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 in a semi-quantitative way. The neonates were separated from their parent Daphnia by filtration prior to the acute test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

16.6°dH (=296.31 mg/L CaCO3)

Test temperature:

20.1 - 20.4 °C

pH:

8.2 - 8.3

Dissolved oxygen:

8.6 - 9.0 mg/L

Nominal and measured concentrations:

Nominal concentrations of test substance : 0.625, 1.25, 2.5, 5, 10, 20 and 40 mg/L

Details on test conditions:

TEST SYSTEM:
- keeping water: M4 medium, originally described in Water Research 24 (9), Sept. 1990; 1157-1167
- photoperiod: 16 hours light, 8 hours dark
- feeding during test: none
- aeration: none
- test vessel: 50 mL glass beakers, 20 ml test medium
- number of daphnia per beaker: 10 daphnids (neonates)
- test parameter: immobility
- method of administration: stock solution
- test concentrations (nominal): test concentrations: 0.625, 1.25, 2.5, 5, 10, 20 and 40 mg/L plus 1 control
- number of replicate: 2 (per concentration/control)
- medium renewal: none
- method of initiation: neonates were placed in prepared media
- temperature: 18 - 22°C +/- 1°C

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

1.25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 11.42 - 26.55 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

1.25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 3.59 - 6.41 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

17.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 11.42 - 26.55 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 3.59 - 6.41 mg/L

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 11.42 - 26.55 mg/L

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 3.59 - 6.41 mg/L

Details on results:

Recoveiy rates ranged from 98.1 - 101.7% of nominal values at 0 hours, and from 97.8 - 101.8% of nominal values at 48 hours.

In none of the tested test item concentration 100 % immobilisation was reached within the complete test period. In the respective range finding test a concentration of 32 mg/L resulted in 100% immobilisation.

Based an the results of the range finding test 40.0 mg/L was chosen to be the highest test item concentration within the main test.

The EC100 determined within the range finding test (32 mg/L) is similar to the EC90 (48h) calculated for the main test (30.7 mg/L). The EC50 of the test item can be determined. A determination of an EC100 for this test item is difficult as no clear dose/response relationship is obvious at test item concentrations above 20 mg/L.

Validity criteria fulfilled:

yes

Remarks:

(- The immobilisation in controls < 10% by the end of the test. - The dissolved oxygen conc. >3 mg/L throughout the exposure period.- substance concentration > 80% during test)

Conclusions:

In order to test acute toxicity to daphnia the test item showed EC 0 = 1.25 mg/L, EC 100 > 40mg/L and an EC50 = 4.8 mg/L after 48 hours.

Executive summary:

In order to test acute toxicity to invertebrates of the substance, Daphnia Magna was exposed to the test solution of 7 nominal

concentration (0.625, 1.25, 2.5, 5, 10, 20 and 40 mg/L) of the test substance and blank control solution for a period of 48 h under static conditions. Mobility and visible abnormalities were recorded 24 and 48 h.

The test item showed EC 0 = 1.25 mg/L, EC 100 > 40mg/L and an EC50 = 4.8 mg/L after 48 hours according to the OECD method 202 .

This toxicity study is classified as acceptable and satisfies the guideline requirements for the actue daphnia study.

Description of key information

In order to test acute toxicity to daphnia the test item showed EC 0 = 1.25 mg/L, EC 100 > 40mg/L and an EC50 = 4.8 mg/L after 48 hours.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

4.8 mg/L

Additional information

In none of the tested test item concentration 100 % immobilisation was reached within the complete test period. In the respective range finding test a concentration of 32 mg/L resulted in 100% immobilisation.

Based an the results of the range finding test 40.0 mg/L was chosen to be the highest test item concentration within the main test.

The EC100 determined within the range finding test (32 mg/L) is similar to the EC90 (48h) calculated for the main test (30.7 mg/L). The EC50 of the test item can be determined. A determination of an EC100 for this test item is difficult as no clear dose/response relationship is obvious at test item concentrations above 20 mg/L.