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
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
GLP compliance:
yes (incl. QA statement)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Analysis of the test media samples was conducted on fresh media at 0 hours and on corresponding old media at 72 hours. Measured test concentrations were determined from samples of test solution from each treatment and control group.

Test solutions

Vehicle:
no
Details on test solutions:
A 147 mg test substance/L solution was prepared by adding ca 296.54 mg of test substance to 2000 mL of EC medium and stirred for 1 hour (test media code = TM1). After settlement for 1 hour the test solution was removed by siphoning and the collected solution was checked for the tyndall effect using a Hach 2100 N turbidity meter. The turbidity meter confirmed that there was no dispersed test substance present and therefore the test solution was used to prepare the remaining test solutions

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test organism, Pseudokirchneriella subcapitata (Strain 278/4), 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:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Test conditions

Hardness:
Hardness (mg CaCO3/L)
38 and 42 (two batches used)
Test temperature:
Temperature Range (°C)
21.6 – 23.1°C
pH:
7.50 – 8.54
Salinity:
Alkalinity (mg CaCO3/L)
26 and 25 (two batches used)
Conductivity:
193 -234 μS/cm
Nominal and measured concentrations:
The measured test substance concentrations were between 84.2 – 104 % of nominal test substance concentrations at 0 hours and 92.4 - 137 % of nominal concentrations at 72 hours.

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 147 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other:
Remarks:
pH adjusted
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 147 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other:
Remarks:
pH adjusted
Details on results:
The 72-hour EyC50, EbC50 and ErC50 values based on nominal test substance concentrations were estimated to be 93.0, 93.3 and 86.2 mg/L when not pH adjusted and >147 mg/L when pH adjusted.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes