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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
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Body responsible for the test

Data source

Reference
Reference Type:
other: Body responsible for the test
Title:
Unnamed

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: 92/69/EEC, C3
Deviations:
not specified
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Solution

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes

Test organisms

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

Study design

Test type:
not specified
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.08 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 0.08 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 0.08 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
biomass

Any other information on results incl. tables

%Concentration loss over test: 21

ErC50 (0 to 24h) 0.080 mg/L.

Water hardness is not measured.

The test concentration of 0.10 mg/L was the highest attainable test concentration due to the limited solubility of the test material in water and auxiliary solvent, and having due regards for the amount of auxiliary solvent permitted in the test under the OECD Guidelines.

Analysis of the test solutions at 0 and 72 hours showed a marked decline in test concentrations and so it was considered justifiable to bas the results on the time-weighted mean measured test concentration also. Given that pre-study stability analysis showed the test material to be stable in the culture medium used over the study period, the decline in measured test concentrations is considered to be due to adsorption to the algal cells. Adsorption was not a factor in the pre-study analyses as no algal cells were present.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
Due to its low water solubility, the test substance is not considered to be toxic to aquatic algae or cyanobacteria under the condition of the test.