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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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:
17-acetyl-17-hydroxyestr-4-en-3-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.