Methyl 4-cyano-5-[[5-cyano-2,6-bis[(3-methoxypropyl)amino]-4-methyl-3-pyridyl]azo]-3-methyl-2-thenoate

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

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)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC/MS/MS

Details on sampling:

Control: at 48 hours (on 2017-02-16)
Test concentration/s: 100 mg/L (nominal) in the freshly prepared media (on 2017-02-14 and 2017-02-15) and in the media after 24 h of exposure (on 2017-02-15 and 2017-02-16) according to the semi-static conditions

Vehicle:

no

Details on test solutions:

Pre-treatment of test item and preparation of test item concentrations
- 100.3 mg of the test item on 2017-02-13 and 100.2 mg of the test item on 2017-02-14 were added to 1 litre of dilution water, treated for 1 h in an ultrasonic bath and stirred for 24 h on a magnetic stirrer
- undissolved particles of the test item were removed by filtration using a folded filter (pore size: 7 - 12 μm) and an aseptic filter (Sartobran sterile capsules, pore size: 0.45 μm + 0.2 μm)
- pH was measured to be 7.8 on 2017-02-14 and 7.7 on 2017-02-15
- 50 mL of the solution were taken and diluted with 0.5 mL of dilution water

Test organisms (species):

Daphnia magna

Details on test organisms:

- 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:

yes

Total exposure duration:

48 h

Hardness:

14.1 °dH (= mg/L CaCO3)

Test temperature:

20.0 - 20.8 °C

pH:

7.8 - 8.0

Dissolved oxygen:

8.8 - 9.1

Nominal and measured concentrations:

nominal: 100 mg/L
measured: <0.003 mg/L
After 24 h a concentration of 0.00714 mg/L was measured. However, this value was considered as an outlier, as all other measured values were below the quantification limit of the HPLC/MS/MS analysis (0.003 mg/L). Possibly the high value was caused accidently by an unfiltered test item particle.

Details on test conditions:

Exposure conditions
Test vessels: 100 mL glass beakers covered with watch glasses holding 5 neonates in 50 mL of test medium
Experimental design: 1 test concentration 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: 19.2 to 19.4 °C
- Aeration: none
- Test item concentration/s: 100 mg/L (nominal)
- Method of administration: direct weighing
- Medium renewal: daily
- Duration of exposure: 48 hours
- Criteria of effects: item-induced alteration of the normal mobility behaviour and the loss of locomotory actions of the neonates, observed at 24 and 48 hours

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.003 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

nominal: 48h-EC50 > 100 mg/L

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:

After 48 hours of exposure no toxic effects of Macrolex Rot B against Daphnia were observed at a limit test concentration of 0.003 mg/L (nominal 100 mg/L).

Executive summary:

A study was conducted 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). The study was performed to assess the acute toxicity to Daphnia magna STRAUS under semi-static conditions. The Daphnia were exposed to a limit test concentration of nominally 100 mg/L of Macrolex Rot B dissolved in dilution water.

Auxiliaries used to prepare the test media were a an ultrasonic bath, a magnetic stirrer, a folded filter and an aseptic filter. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. After 48 hours of exposure an EC50 of higher than 0.003 mg/L was determined. All results are expressed in terms of nominal concentrations and analytical values. All measurements, except the measurement in the media after 24 hours of exposure on 2017-02-15, which was considered as an outlier, were below the quantification limit of the HPLC/MS/MS analysis (0.003 mg/L).

No toxic effects of Macrolex Rot B against Daphnia were observed at a limit test concentration of 0.003 mg/L (nominal 100 mg/L) after 48 h under exposure conditions.

Description of key information

After 48 hours of exposure no toxic effects of Macrolex Rot B against Daphnia were observed at a limit test concentration of 0.003 mg/L (nominal 100 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.003 mg/L

Additional information

Should read: EC50 > 0 .003 mg/L