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
Study period:
16/12/2016 - 17/02/2017
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 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Strain: ATCC22662
Source: American Type Culture Collection
Date of receipt: June 20, 1996
Maintenance of obtained algae: Algae have been maintained by period subculture using Gorham medium. Algae are kept under sterile condition. Sterile test has been performed periodically, every six months, to confirm that the algae are not contaminated.

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
72 h

Test conditions

Test temperature:
21.4 - 21.7 °C
pH:
7.8 - 10.3
Details on test conditions:
Test vessels and other apparatus were sterilized as necessary. Algae were introduced into culture medium by an aseptic technique.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 82.5 mg/L
Nominal / measured:
meas. (initial)
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
13.4 mg/L
Nominal / measured:
meas. (initial)
Basis for effect:
growth rate
Details on results:
In all test groups, the color of the test cultures (as observed with the naked eye) showed a tendency to get more greenish during the exposure period.
By microscopic observation at the end of exposure, in all concentration groups neither unusual cell shape of algae (contraction, expansion, damaged cell etc.) nor agglutination was observed, and the algae looked normal compared with those in the control group.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
A growth inhibition test of the test substance with Pseudokirchneriella subcapitata was conducted in order to determine the 50% growth inhibition concentration (EC50) and the no observed effect concentration (NOEC) after 72-hour exposure.

The results were calculated from the time weighted mean of measured concentrations.
50% growth inhibition concentration, ErC50 (0-72h): >82.5 mg/L
No observed effect concentration, NOECr (0-72h): 13.4 mg/L
Executive summary:

A growth inhibition test of the test substance with Pseudokirchneriella subcapitata was conducted in order to determine the 50% growth inhibition concentration (EC50) and the no observed effect concentration (NOEC) after 72-hour exposure.

The results were calculated from the time weighted mean of measured concentrations.

50% growth inhibition concentration, ErC50 (0-72h): >82.5 mg/L

No observed effect concentration, NOECr (0-72h): 13.4 mg/L