2,2'-[azobis(1-methylethylidene)]bis[4,5-dihydro-1H-imidazole dihydrochloride

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27/17-31/10/14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
- Sampling method:
- Sample storage conditions before analysis: at room temperature

Vehicle:

no

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Strain:
- Source: Forellenzucht Kasselmann, Forellental 12, 49170 Hagen, Germany
- Age at study initiation (mean and range, SD):
- Length at study initiation (length definition, mean, range and SD): 5.94 cm
- Weight at study initiation (mean and range, SD): 2.66 g
- Method of breeding:
- Maintenance of the brood fish:

ACCLIMATION
- Acclimation period: at least 7 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food during acclimation: Forellenfutter Zuchtfutter 0.8-1.2 mm (Teichcenter-Rieger, Nüdlingstr. 13, 63607 Wächtersbach-Aufenau); 1.5 % of fish bw
- Feeding frequency during acclimation: daily, but fish were not fed 24 h before test
- Health during acclimation (any mortality observed): not stated

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

FEEDING DURING TEST
- Food type:
- Amount: no
- Frequency: no

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

10-250 mg CaCO3/L

Test temperature:

14.3 ± 0.1 °C

pH:

6.89-7.36

Dissolved oxygen:

> 90 %

Nominal and measured concentrations:

100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 59 L glass aquaria
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 59 L volume, 40 L water per vessel
- Aeration: gentle aeration
- Type of flow-through (e.g. peristaltic or proportional diluter): no
- Renewal rate of test solution (frequency/flow rate): after 24 h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 0
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water (local origin)
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine: filtered by active charcoal + 24 h aeration
- Alkalinity:
- Ca/mg ratio:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 /8 h
- Light intensity: 0.1 - 10 µmol photons x m-2 x s-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

nominal test item	cumulative mortality (%) after different exposure periods [hours]
concentration [mg/L]	24	48	72	96
100	0	0	0	0
control	0	0	0	0

Validity criteria fulfilled:

yes

Conclusions:

In this study, Azo Initiator VA044 was found to cause no toxic effects to Rainbow Trout after 96 hours when tested with the limit concentration of nominal 100 mg/L. The LC50 after 96 hours (nominal concentration) was > 100 mg/L.

Executive summary:

The acute toxicity of the test item Azo Initiator VA044 (batch no.: N10415) to fish (rainbow trout) was determined according to OECD-Guidelline for testing of chemicals No. 203 (1992) from 2014 -10 -27 to 2014 -10 -31 at Dr. U. Noack-Laboratorien, 31157 Sarstedt, Germany.

A semi-static test with the limit concentration of 100 mg test item/L was carried out with daily renewal of the test media under reduced light intensity due to the light sensitivity of the test item. The duration of the test was 96 hours. Seven test organisms were exposed to the limit concentration and the control. Water quality parameters, temperature, pH-value and O2 saturation measured at 0, 24, 48, 72 and 96 hours were within the acceptable limits.

The validity criteria of the guideline were fulfilled.

The test item Azo Initiator VA044 is a white powder and has a water solubility of 347 g/L at 25 °C. For the preparation of the limit concentration, the relevant amount of the test item was freshly prepared with dilution water by weighting the appropriate amount, transferring it directly into the test vessel containing the respective volume of dilution water and mixing it with an ultraturrax before the start of each 24 h exposure interval. The test solution was visually clear throughout the exposure period.

The concentrations of the test item Azo Initiator VA044 were determined via LC-MS from freshly prepared media after 0 ans 72 h and from the corresponding 24 h old media after 24 h and 96 h. The measured concentration ot the test item in freshly prepared media at 0 and 72 h were 100 and 105 % of the nominal test item concentration, respectively, and 100 % each in the corresponding 24 h aged test media.

As no mortality was observed during the test, the effect value LD50, 96 h was determined to be > 100 mg test item/L.

Description of key information

Based on the findings in the limit test according to OECD guideline 203 no effects were observed up to the test concentration of 100 mg test item/L For the chemical safety assessment an LC50(96h) of 100 mg/L for fish is assumed as worst case.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L