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
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:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Remarks:
LC-TOF/MS

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test organism was originally obtained from the culture collection of algae and protozoa and is a representative species of the freshwater aquatic phytoplankton.
Prior to testing, duplicate starter cultures were prepared and incubated under test conditions to obtain sufficient algal cells in exponential growth and to achieve a starting algae cell density of 1x10e+4 cells/mL.

Study design

Test type:
static
Water media type:
other: reverse osmosis water
Limit test:
yes
Total exposure duration:
72 h
Post exposure observation period:
Cell density counts were performed at 24, 48, 72h using a particle counter and confirmed manually using a haemocytometer.

Test conditions

Hardness:
Not specified
Test temperature:
21-24°C
pH:
7.49-9.35
Dissolved oxygen:
Not specified
Nominal and measured concentrations:
Nominal: 10 mg/L
Measured: 8.76 mg/L at 0h and 7.68 mg/L at 72h
Details on test conditions:
Incubation under 4440-8880 lux light intensity
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 8.76 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 8.76 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 8.76 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
other: yield
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 8.76 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
other: yield
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 8.76 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 8.76 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
biomass

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
As the measured concentration at 72 hour (with algae) were within 80% of the initial measured concentration, but only 77% of the nominal concentration, it was considered justifiable to base the results on initial measured concentration as recommended in the OECD 201 guideline.
Based on initial measured concentrations, the 72-h EyC50 (yield), EbC50 (biomass) and ErC50 (growth rate) values were calculated to be > 8.76 mg/L, respectively. The corresponding NOEC values for yield, biomass and specific growth rate after 72 hours were 8.76 mg/L respectively.
Medrane was considered not to inhibit the growth of Pseudokirchneriella subcapitata at concentrations of up to 8.76 mg/L.