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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well performed OECD and GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report date:
2009

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
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

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
CHODAT SAG 86.81

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Test conditions

Test temperature:
21 - 24 °C
pH:
7,0 - 8,2
Reference substance (positive control):
yes
Remarks:
Potassium dichromate CAS 7778-50-9

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: na
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
50.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Remarks on result:
other: 42.5 - 58.1 mg/L

Any other information on results incl. tables

   Rate-related Inhibition (mg/L)
 NOEC  25.0
 LOEC  50.0
 ErC10  43.8 (37.9 - 52.8)
 ErC20  88,5 (77.1 - 98.3)
 ErC50  > 100
   Inhibition of Yield
  NOEC  12,5
  LOEC  25.0
  EyC10  16.3 (13.3 - 19.7)
  EyC20  22.6 (19.1 - 27.0)
  EyC50  50.1 (42.5 - 58.1)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test item was found to inhibit the growth of fresh water green alga Desmodesmus subspicatus after 72 h with the following concentrations
specific growth rate ErC50 > 100 mg/L
yield EyC50 42.5 - 58.1 mg/L
Executive summary:

As ErC50 for growth rate inhibition is > 100 mg/L no classification is required