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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:
December 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: particulates

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

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

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 8.49 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: saturated solution

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The EC50/72 h is higher than a saturated solution with 8.49 mg/L. However, the toxicity threshold for algae is below 8.49 mg/L, since the inhibition of growth reached 31% at the highest concentration tested.
Executive summary:

Algae Desmodesmus subspicatus were incubated with the test material in a limit test over aperiod of 72 h. The test substance concentrations were 0.09, 0.85, and 8.49 mg/L. The test cocentrations were a saturated solution prepared by suspending 100 mg/L and stirring for 24 h, and dilutions of 1:10 and 1:100 thereof.

The growth was inhibited at the hihgest concentration to 31%. Thus, the EC50 is higher than a saturated solution (8.49 mg/L), but the toxicity threshold for algal growth inhibition is below a saturated solutiuon. The NOEC was 0.68 mg/L.