N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-08-14 to 1989-09-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study performed according to OECD Guideline but solvent was used.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide

EC Number:

247-820-7

EC Name:

N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide

Cas Number:

26576-46-5

Molecular formula:

C11H11N3O3

IUPAC Name:

3-oxo-N-(2-oxo-2,3-dihydro-1H-benzimidazol-5-yl)butanamide

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- One aliquot part of 100mL was taken from the total volume of 10L
- Sample was clear
- Water temperature was 22°C +/- 1°C during toxicity testing

Test solutions

Vehicle:

yes

Details on test solutions:

Diliuton water:
- Reconstituted water according to ISO/DIS 7346/1 was used
- Water was ventilated until oxygen saturation was reached
- pH was determined prior to testing and was between 8.2 and 8.3

Test item:
- Test item was wetted with 0.095mL of Tween 80 per litre to facilitate dissolving; then dilution water was added; both was homogenised using ultrasonic bath and ultra turrax
- While stirring with a glas bar the homogenises solution was transferred to the bassin
- The whole volume was stirred for 2hrs using a KPG-stirrer
- The test item was dissolved with minor sedimentation of the test item on the ground of the vessel and at the water surface. 96hrs after exposure a minor blurring was observed
- To determine the actual concentration of dissolved test item water samples were taken at the beginning of the test and after 48hrs and 96hrs. Samples were taken from the middle of the bassin. Analytical determined mean values were above 80%

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

- Origin: West Aquarium, 3422 Bad Lauterberg
- Date of birth: 1989-05-14
- Date of delivery: 1989-08-03
- Fishes were adapted to the water and surrounding conditions for at least 14d prior to exposure
- Water tempereature: 22°C +/- 1°C
- Oxygen concentration: >= 80% of oxygen saturation
- Illumination: 12hrs per day
- Animal density: =< 1g fish per litre water
- Feeding: twice a day, ad libitum
- Feed: Tetra Min, Tetra Werke, Melle
- Prior to testing, 10 fishes were randomly picked to be representatively measured for their body size; these 10 fishes were not used for the experiment

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test conditions

Test temperature:

22°C +/-1°C

pH:

8.2 - 8.3

Dissolved oxygen:

>= 80%

Nominal and measured concentrations:

Nominal: 500mg/L
Measured: 475.3mg/L, equalling 95.1% (506, 431 and 489 mg/l at d0, d2 and d4)

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 500 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

mortality (fish)

Remarks on result:

other: none

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 500 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

mortality (fish)

Remarks on result:

other: none

Details on results:

- No lethality observed at 500mg/L during the whole experiment
- Therefore, LD50 after 48hrs and 96hrs is above 500mg/L
- Fish from the control group (Tween 80) and the 500mg/L test item group exhibited impairment of breathing, altered swimming behaviour and altered general behaviour

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

Testing for lethal effects of Acetolon TTR was done using Brachydanio rerio following the above described Guidelines. Over a period of 96hrs no lethal effects were observed at a concentration of 500 mg/L. Therefore, LC50 for 48hrs and 96hrs is above 500mg/L.

Due to dissolving behaviour of Acetolon TTR in dissolving pre-test, Tween 80 was used as a solubiliser. Possible effects of Tween 80 were assessed in a solvent control, using 0.095mL of Tween 80 per litre.

The test item was dissolved with minor sedimentation of the test item on the ground of the vessel and at the water surface. 96hrs after exposure a minor blurring was observed.

To determine the actual concentration of dissolved test item water samples were taken at the beginning of the test, after 48hrs and 96hrs. Samples were taken from the middle of the bassin. Analytical determined mean values were at this time points always well above 80%.

Since LC50 > 500 mg/L after 96 hours no classification is required