Registration Dossier

Diss Factsheets

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:
other information
Study period:
11-2004 to 08-2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well reported GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report date:
2004

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
Gestonorone
EC Number:
218-378-2
EC Name:
Gestonorone
Cas Number:
2137-18-0
Molecular formula:
C20H28O3
IUPAC Name:
14-acetyl-14-hydroxy-15-methyltetracyclo[8.7.0.0²,⁷.0¹¹,¹⁵]heptadec-6-en-5-one

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:
no
Total exposure duration:
72 h

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.4 mg/L
Basis for effect:
biomass

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Gestonorone had a concentration-depended inhibitory effect on the growth of Desmodesmus
subspicatus. The EbC50 (biomass) was 0.4 mg/L, the ErC50 (growth rate) was 2.4 mg/L on the
basis of measured concentrations by TOC.
Consequently, Gestonorone was considered to be very toxic to the green algae Desmodesmus
subspicatus, since the EbC50 was lower than 1 mg/L.
Executive summary:

Gestonorone had a concentration-depended inhibitory effect on the growth of Desmodesmus

subspicatus. The EbC50 (biomass) was 0.4 mg/L, the ErC50 (growth rate) was 2.4 mg/L on the

basis of measured concentrations by TOC.

Consequently, Gestonorone was considered to be very toxic to the green algae Desmodesmus

subspicatus, since the EbC50 was lower than 1 mg/L.