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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:
1991-04-30 to 1991-05-03
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: according to EU Guideline

Data source

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

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Version / remarks:
as 79/831/EEC
Deviations:
not specified
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
m-(4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulphonic acid
EC Number:
204-303-0
EC Name:
m-(4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulphonic acid
Cas Number:
119-17-5
Molecular formula:
C10H10N2O4S
IUPAC Name:
3-(3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)benzene-1-sulfonic acid

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
no data

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: green alga
- Strain: SAG 86.81
- Source (laboratory, culture collection): laboratory cultivation
- Method of cultivation: continous laboratory cultivation

Study design

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

Test conditions

Test temperature:
23 +- 2° C
pH:
Control: pH 7.01 - 9.12
Test item: 6.08 - 9.26

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
8.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
78 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
31 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The ErC50 for the growth rate is > 100 mg/L. Therefore the test item has not to be classified as toxic for algae
Executive summary:

The results reflect the nominal concentrations of the test item resulting in a growth inhibition of 10%, 50% or 90% compared to the control after 72 hrs of exposure.

Effects on biomass:

EbC 10 = 8.8 mg/L

EbC 50 = 78 mg/L

EbC 90 > 100 mg/L

Effects on growth rate:

ErC 10 = 31 mg/L

ErC 50 > 100 mg/L

ErC 90 > 100 mg/L