Registration Dossier

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study according to OECD guideline 201 under GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Physical state: solid
- Analytical purity: >99%

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)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): At the test start, the test substance was very finely and homogeneously suspended in the test medium. After about one hour, test substance particles were observed at the water surface. After one day, substance particles were observed at the water surface and the bottom of the beaker. Tes flasks, however, were continuously stirred.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
Strain: No. 86.81 SAG
Supplier: University of Göttingen, Germany

Study design

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

Test conditions

Hardness:
0.24 mmol/l as CaCO3
Test temperature:
23°C
pH:
7.8 - 8.9
Nominal and measured concentrations:
Mean measured concentrations of dissolved and suspended test substance in the unfiltered sample of the suspensions was 89% and 83% of the nominal value with a total mean of 86%.

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC0
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC0
Effect conc.:
> 100 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
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 100 mg/L
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 100 mg/L
Basis for effect:
growth rate
Details on results:
- Effect concentrations exceeding solubility of substance in test medium: Yes
- No effects on the shape of the algal cells were found by microscopic examination
Results with reference substance (positive control):
not applicable
Reported statistics and error estimates:
not applicable

Any other information on results incl. tables

Since neither any classification criteria according to GHS/CLP (Regulation (EC) No. 1272/2008) nor any criteria according to DSD (Directive 67/548/EEC) are fulfilled, the substance is not classified for environmental hazards.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
As no effects on biomass and algal growth was observed, the 72-hour LC0 (NOEC) was determined to be at least 100 mg/l.
Executive summary:

Due to the low water solubilty of the test item, an unfiltrated supersaturated suspension with a nominal concentration of 100 mg/l was used as the test medium, containing a max. concentration of the test substance.

During the test period the mean measured concentration of dissolved and suspended test substance in the unfiltrated duplicate samples of the suspension was 89% and 83% of the nominal value. Under the test conditions, the concentration was sufficiently constant during the 72-hours test period. The concentration of dissolved and very finely suspended test substance was below the detection limit of approx. 1.0 mg/l.

As no no effects on biomass and algal growth was observed, the 96-hour LC0 (NOEC) was determined to be at least 100 mg/l nominal.