Reaction mass of methyl 2-[[(E)-(2,4-dimethylcyclohex-3-en-1-ylidene)methyl]amino]benzoate and methyl 2-[[(Z)-(2,4-dimethylcyclohex-3-en-1-ylidene)methyl]amino]benzoate

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:

27 June 2000 - 29 June 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

A limit test was conducted at saturated test item concentration. Test concentrations were analysed by TOC analysis.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentration: Control and 3.5 mg/L (saturated)
- Sampling method: Samples collected at the test start and after 48 hours of exposure

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution of 30 mg/L was prepared by weighing the test substance into water and treating for 60 seconds at 8000 rpm with an ultra turrax and then stirring for 24 hours on a magnetic stirrer. The emulsion was then filtered using a folded filter (pore size 7 to12 µm).
- Controls: M4-medium according to Elendt and BGA (1992)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: STRAUS, parthenogenetic females
- Source: Laboratory-bred
- Age at study initiation: 0-24 h

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

15.4 °dH

Test temperature:

20.3 and 20.8 °C at 48 hours

pH:

7.8 and 7.9 at 48 hours

Dissolved oxygen:

8.7 and 8.9 mg/L at 48 hours

Nominal and measured concentrations:

Nominal concentration: 3.5 mg/L
Arithmetic mean measured concentration: 3.9 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Cylindrical test vessels, diameter 4.0 cm, height 6.5 cm, not ventilated
- Fill volume: 20 mL
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light/8 hours dark

EFFECT PARAMETERS MEASURED: Number of immobile daphnids recorded after 24 and 48 hours. Oxygen, pH and water temperature were determined from the total volume of the parallel solutions at 48 hours.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 3.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

15% immobilsation rate at 3.9 mg/L

Duration:

48 h

Dose descriptor:

other: EC15

Effect conc.:

3.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Table 1. Immobilisation results

Arithmetic mean measured concentrations (mg/L)	Cumulative immobilised daphnids (n=20)		% immobilised daphnids (n=20)
	24 hours	48 hours	24 hours	48 hours
Control	0	0	0	0
3.9	0	3	0	15

Validity criteria fulfilled:

yes

Remarks:

The validity criteria of the test guideline permit a maximum immobilisation rate of 10% for control daphnia (actual: 0%).

Conclusions:

The 48 h EC50 for the test item, based on immobilisation of Daphnia magna, was >3.9 mg/L. 15% immobilisation was determined at a measured concentration of 3.9 mg/L.

Executive summary:

A limit test was performed to assess the acute toxicity of the test item to Daphnia magna over 48 hours in a static system. A stock solution of 30 mg/L test item was prepared by weighing the test substance into water and treating for 60 seconds with an ultra turrax and then stirring for 24 hours on a magnetic stirrer. The emulsion was then filtered. The limit test was conducted at a nominal concentration of 3.5 mg/L (arithmetic mean measured concentration 3.9 mg/L, based on TOC analysis) alongside a control. The 48 h EC50 based on immobilisation was determined to be >3.9 mg/L. 15% immobilisation was determined at a measured concentration of 3.9 mg/L. This study is GLP-compliant and was performed according to EU Method C.2. This study is considered reliable with restrictions (Klimisch 2) as there were limitations in reporting and test concentrations were analysed using a non-(substance)-specific analytical technique.

Description of key information

The 48 h EC50 for the test item, based on immobilisation of Daphnia magna, was > 3.9 mg/L. 15% immobilisation was determined at a measured concentration of 3.9 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

3.9 ng/L

Additional information

A limit test was performed to assess the acute toxicity of the test item to Daphnia magna over 48 hours in a static system. A stock solution of 30 mg/L test item was prepared by weighing the test substance into water and treating for 60 seconds with an ultra turrax and then stirring for 24 hours on a magnetic stirrer. The emulsion was then filtered. The limit test was conducted at a nominal concentration of 3.5 mg/L (arithmetic mean measured concentration 3.9 mg/L, based on TOC analysis) alongside a control. The 48 h EC50 based on immobilisation was determined to be >3.9 mg/L. 15% immobilisation was determined at a measured concentration of 3.9 mg/L. This study is GLP-compliant and was performed according to EU Method C.2. This study is considered reliable with restrictions (Klimisch 2) as there were limitations in reporting and test concentrations were analysed using a non-(substance)-specific analytical technique.