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
Study period:
from 1994-09-20 to 1994-10-15
Reliability:
1 (reliable without restriction)
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Version / remarks:
directive 92/69/EEC
Deviations:
no
Principles of method if other than guideline:
NA
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
NA
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
NA

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Frequency: at t=0 h and t= 96h
Volume: 10 mL

Test solutions

Vehicle:
yes
Details on test solutions:
The test solutions were prepared using a stock solution in ISO-medium. For this purpose the test substance was added quantitatively to obtain a nominal concentration of 100 mg/L. From this stock solution the required volumes for preparation of the test concentrations were added to ISO-medium. The final volume of the test solutions was 50 mL per vessel. Subsequently, a volume of 0.59 mL of the algal suspension was added to each Vessel providing a concentration of 1 x 10000 algal cells/mL. At the start of the test all test solutions were clear.

Test organisms

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

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Post exposure observation period:
NA

Test conditions

Hardness:
24 mg CaCO3/L
Test temperature:
The temperature ranged from 21 to 22 °C.
pH:
The pH-values ranged from 8.0 to 8.4 at 0h and 96h.
Dissolved oxygen:
NA
Salinity:
NA
Nominal and measured concentrations:
At the start of the test, the actual test concentrations were in agreement with nominal at 32 and 100 mg/L. The actual concentrantions measured in the sample taken 10 mg/L was ca. 30 % higher than nominal due to an interfering response recorded in the test medium. At the end of the 96-hour period the measured concentrations had not decreased by more than 20 % in any of the samples.
Details on test conditions:
NA
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrations
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
NA
Results with reference substance (positive control):
Concentrations: 0.18, 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L
The nominal 72-hour EC50 for growth inhibition (EBC50:0-72h) was 0.32 mg/L with 95 % fiducial limits: 0.20 - 0.44 mg/L.
The nominal 72-hour EC50 for growth rate reduction (ErC50: 0-72h) was 0.88 mg/L with 95 % fiducial limits: 0.65 - 1.42 mg/L.
Reported statistics and error estimates:
NA

Any other information on results incl. tables

no remarks

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
EC50 > 100 mg/L
Executive summary:

No inhibition of cell growth or reduction of growth rate was recorded at any of the concentrations of the test item tested. Hence, the EC50 values for both, cell growth inhibition (EBC50: 0 -96h) and growth rate reduction (ERC50: 24 -96 h) were beyond the range tested, i.e. > 100 mg/L.