N,N''-(isobutylidene)diurea

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:

13. - 17 Oct 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

No information on stability of test substance under test conditions available, no analytical monitoring.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1984

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Preparation of the test substance: the substance was added to the test water without any pretreatment; subsequently the fish were placed into the aquaria.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Forellenhof Fredelsloh, Dr . med. vet. Otto Mueller, D-3413 Moringen 1, FRG
- Length at study initiation (length definition, mean, range and SD): 5.7 cm (4.9 - 6.5 cm)
- Weight at study initiation (mean and range, SD): 2.2 g (1.4 - 3.4 g)
- Feeding during test: no


ACCLIMATION
- Acclimation period: 10 weeks
- Acclimation conditions (same as test or not): no, flow though
- Type and amount of food: Growing feef F/B 50, SSNIEF Spezialdiaeten GmbH, D-4770 Soest, Frg, ad libitum
- Health during acclimation (any mortality observed): no mortalities
- Medical treatment: once with 10 mg/L Tetracycline hydrochloride, twice with 0.05 mg/L Malachite green chloride

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

2.5 mmol/L

Test temperature:

12 °C (± 0°C)

pH:

8.3 (8.1-8.6)

Dissolved oxygen:

9.7-11.4 mg/L

Nominal and measured concentrations:

Nominal concentration tested: 1000 mg/L (this selection was based on the results of a range finding study which resulted in a LC50 after 96 hours of 1000 mg/L). No analytical dose verification.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass aquarium with a stainless steel frame (80 cm x 35 cm x 46 cm)
- Aeration: yes, slight
- No. of organisms per vessel: 10
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.22 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted freshwater according DIN 34812, Part 11, Draft Sept. 1981
Preparation from fully demineralized tap water
- Ca/mg ratio: 4:1
- Conductivity: max. 10 micro MHO


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, abnormal symptoms
Determination of mortality and symptoms: at 1, 4, 24, 48, 72, 96 hours.


TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: selection was based on the results of a range finding study which resulted in a LC50 after 96 hours of 1000 mg/L

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Mortality and behaviour

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: none
- Mortality of control: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Undissolved test substance was visible on the water surface and on the bottom of the aquarium.

Sublethal observations / clinical signs:

No symptoms were noted. No mortality.

Description of key information

With high probability not acutely harmful to fish.

Additional information

In a non GLP study on the acute toxicity to fish (static, performed similar to OECD guideline 203), no mortalities were observed up to 1000 mg/l IBDU (LC50(96 h) > 1000 mg/l, nominal). Salmo gairdneri was used as test organism. The substance (1000 mg/l) was added to the test water without any pretreatment. Undissolved test substance was visible on the water surface and on the bottom of the aquarium.