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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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
(17R)-17-hydroxy-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)-1,4,7,8,9,10,12,13,14,15,16,17-dodecahydrospiro[cyclopenta[a]phenanthrene-3,2'-[1,3]dioxolan]-11(2H)-one
EC Number:
616-077-4
Cas Number:
74332-34-6
Molecular formula:
C25H36O6
IUPAC Name:
(17R)-17-hydroxy-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)-1,4,7,8,9,10,12,13,14,15,16,17-dodecahydrospiro[cyclopenta[a]phenanthrene-3,2'-[1,3]dioxolan]-11(2H)-one

Sampling and analysis

Analytical monitoring:
yes
Remarks:
LC-MS/MS TOF

Test organisms

Test organisms (species):
Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test organism was originally obtained from the Culture Collection of Algae and Protozoa (CCAP) and is a representative species of the freshwater aquatic phytoplankton.

Study design

Test type:
not specified
Water media type:
other: reverse osmosis water
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
Cell density of the vial contents was determined.

Test conditions

Hardness:
No information
Test temperature:
22-23.4°C
pH:
7.32 to 8.02 at test start
Dissolved oxygen:
No information
Nominal and measured concentrations:
Nominal: 1.0, 3.2, 10, 32 and 100% saturated solutions
Measured: 0.0103, ,0.0233, 0.0685, 0.131 and 0.296 mg/L
Details on test conditions:
Test vessels incubated with 10e4 algae cells/mL
Incubation under 4440-8880 lux light intensity
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 0.264 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
other: yield
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 0.131 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
other: yield
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.296 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 0.131 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.296 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 0.069 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
As the measured concentrations were outside the range of 80-120% of the nominal exposure concentrations of cetoxenone is required to report the test concentrations in terms of nominal concentrations, the end points, were reported in terms of geometric mean measured concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Based on geometric mean measured concentrations, the 72-h EyC50 (yield), EbC50 (biomass) and ErC50 (growth rate) values were calculated to be 0.264, > 0.296, > 0.296 mg/L respectively.
Based on geometric mean measured concentrations, the corresponding NOEL values for yield, biomass and specific growth rate after 72 hours were 0.131, 0.131 and 0.0685 mg/L respectively.