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:
31st August 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions. This study was performed in compliance with the GLP regulations. Only memorandum available; no full study report.

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
not specified
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
not specified
Principles of method if other than guideline:
No further details were provided.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
No further details were provided.
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
No further details were provided.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
No further details were provided.

Test solutions

Vehicle:
not specified
Details on test solutions:
No further details were provided.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
No further details were provided.

Study design

Test type:
not specified
Water media type:
not specified
Remarks on exposure duration:
No further details were provided.
Post exposure observation period:
No further details were provided.

Test conditions

Hardness:
No further details were provided.
Test temperature:
No further details were provided.
pH:
No further details were provided.
Dissolved oxygen:
No further details were provided.
Salinity:
No further details were provided.
Nominal and measured concentrations:
No further details were provided.
Details on test conditions:
No further details were provided.
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
4.8 mg/L
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
46 mg/L
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
74 mg/L
Basis for effect:
growth rate
Details on results:
Since this concentration was below the detection limit of PTH-decahydroamide (Ro 31-9373/000) in water samples, no actual concentration could be determined.
Results with reference substance (positive control):
No further details were provided.
Reported statistics and error estimates:
No further details were provided.

Any other information on results incl. tables

No further details were provided.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
PTH-Decahydroamide (Ro 31-9373/000) inhibited cell growth and reduced growth rate of Scenedesmus subspicatus significantly under the conditions of the present study at nominally 10 mg/l and higher. The inhibition rates were estimated for both the algal biomass b and the growth rate R after 72 hours test duration; based on nominal concentrations.
EbC50 (0-72 h)                     46 mg/l
ERC50 (0-72 h)                     74 mg/l
The NOEC was 4.8 mg/l for both cell growth inhibition and growth rate reduction when based on nominal concentrations. Since this concentration was below the detection limit of PTH-decahydroamide (Ro 31-9373/000) in water samples, no actual concentration could be determined.
Executive summary:

The study procedure described was performed on the basis of EC directive 92/69/EEC, C. 3 (1992) and OECD guideline No. 201 (1984).

PTH-Decahydroamide (Ro 31-9373/000) inhibited cell growth and reduced growth rate of Scenedesmus subspicatus significantly under the conditions of the present study at nominally 10 mg/l and higher. The inhibition rates were estimated for both the algal biomass b and the growth rate R after 72 hours test duration; based on nominal concentrations.

EbC50 (0-72 h)                     46 mg/l

ERC50 (0-72 h)                     74 mg/l

The NOEC was 4.8 mg/l for both cell growth inhibition and growth rate reduction when based on nominal concentrations. Since this concentration was below the detection limit of PTH-decahydroamide (Ro 31-9373/000) in water samples, no actual concentration could be determined.