2,2'-azobis[4-methoxy-2,4-dimethylvaleronitrile]

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:

21.-25.08.17

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)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus
- Justification for species other than prescribed by test guideline: -
- Source: Umweltbundesamt Berlin
- Age of parental stock (mean and range, SD):
- Feeding during test
- Food type:
- Amount:
- Frequency:

ACCLIMATION
- Acclimation period:
- Acclimation conditions (same as test or not):
- Type and amount of food:
- Feeding frequency:
- Health during acclimation (any mortality observed):

QUARANTINE (wild caught)
- Duration:
- Health/mortality:

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.502 mmol/L

Test temperature:

20.1 – 22.7 °C

pH:

7.6 - 7.8

Dissolved oxygen:

8.3 - 8.7 mg/L

Nominal and measured concentrations:

nominal: 100 mg/L
measured (geometric mean): 106 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Beakers, glass, nominal volume 50 mL.
- Type (delete if not applicable): -
- Material, size, headspace, fill volume: 20 ± 5 mL
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter): -
- Renewal rate of test solution (frequency/flow rate): -
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): -
- Biomass loading rate: -

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Salinity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod:
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

VEHICLE CONTROL PERFORMED: yes/no

RANGE-FINDING STUDY
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7, CAS No 7778-50-9)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 106 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

EC50 (24h) 1.6 mg/L

Validity criteria fulfilled:

yes

Conclusions:

All Daphnia exposed to the test item (100 mg/L) survived and only one Daphnia was immobilised in the blank control.Therefore, the EC50 (48 h) was determined to be > 106 mg/L.

Executive summary:

One valid experiment was performed.

The study was performed using one concentration at nominally 100 mg/L of test item and one control with four replicates each. 20 Daphnia were exposed to the test item (5 daphnia per replicate) for 48 hours in a static test system. After 23 and 48 hours, the immobilised Daphnia were counted.

All Daphnia exposed to the test item (100 mg/L) survived and only one Daphnia was immobilised in the blank control.

Potassium dichromate K₂Cr₂O₇(CAS No. 7778-50-9) was used as positive controlin a current reference study to assure that the test conditions are reliable.

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using HPLC.

The measured concentration of the test item at the beginning of the test was 85 % of the nominal concentration and at the end of the test 132 % of the nominal concentration.

Therefore, the determination of the biological results was based on the geometric mean of the measured concentration.

The following results were determined for the test item 2,2'-Azobis (4-methoxy-2,4-dimethyl valeronitrile) (species:Daphnia magna).

 

48h-NOEC≥106 mg/L
48h-LOEC > 106 mg/

24h EC 50 > 106 mg/L

48h EC 50 > 106 mg/L

Description of key information

No immobilisation is observed in the OECD 202 guideline study. The highest concentration is used as key value.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L