Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1990-08-01 to 1990-08-10
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study performed according to current OECD-Guidelines and GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report date:
1991

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Version / remarks:
Adopted: 04 April 1984
Deviations:
not specified
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-dihydro-5-nitro-2H-benzimidazol-2-one
EC Number:
202-282-2
EC Name:
1,3-dihydro-5-nitro-2H-benzimidazol-2-one
Cas Number:
93-84-5
Molecular formula:
C7H5N3O3
IUPAC Name:
5-nitro-1,3-dihydro-2H-benzimidazol-2-one

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): substance was diluted using water, then homegenised using ultraturrax and ultrasonic bath; the so prepared test substance was transferred to the testing vessel with stirring. There the whole liquid was stirred for another 2hrs using a glass rod and kpg-stirrer
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): target concentration: 500mg/L, actual measured: 92,9mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): precipitate on the ground
- Concentration was determined at the beginning of the experiment and after 48hrs and 96hrs using HPLC/UV-vis

Test organisms

Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
96 h

Test conditions

Test temperature:
22+/-1°C
pH:
pH = 8,3
Dissolved oxygen:
>=80%
Details on test conditions:
see below

Results and discussion

Effect concentrationsopen allclose all
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 92.9 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Basis for effect:
mortality (fish)
Duration:
96 h
Dose descriptor:
LC0
Effect conc.:
92.9
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Basis for effect:
mortality (fish)
Details on results:
- Behavioural abnormalities: impaired swimming behaviour
- Other biological observations: no lethality neither in the 92,9mg/L (actual concentration, target was 500mg/L) Nitrolon TF nor in the control group
- Abnormal responses: depending on time and to different extent: reduced activity, swimming near to the water surface, irregular breathing...more details see attached table "Symptomatik"
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: precipitation of test material on the ground

Any other information on results incl. tables

Sublethal observations / clinical signs:

To each vessel (control, test substance) 10 fishes were randomly distributed to. Fishes were not feeded during the experiment.

At hours 2 - 4 - 24 - 72 and 96 the tanks were rated for adverse reactions. Though no lethality over the test period was observed, the fishes showed altered behaviour, symtomps increased in number and abundance, correlated with increasing duration of the test period.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
with restrictions due to solubility maximum
Conclusions:
No lethality at max solubility of 92,9 mg/l after 48 and 96 hours. Therefore LC50 is above 92,9 mg/l.
Executive summary:

The test of 5 -Nitrobenzimidazolon TF on Danio rerio over 96 hours revealed no lethal effect at a centration of 92,9 mg/ l (mean), together with unsolved substance residue 500 mg/l test substance in the vessel was present. The test solution was a yellow liquid with excess of test substance as sediment.

At test begin, after 48 and 96 hours a probe from the middle of the water column and in the tank middle was analysed for the concentration of the test substance in the solution. Arithmetic mean was below 80% of the reference concentration of 500 mg/l. Due to concistency of the measured value over the test period, the LC50 is given for the present concentration.