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)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Qualifier:
according to
Guideline:
EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
1.83 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.77 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
9.77 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
3.05 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
1.04 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks:
& biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
1.47 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks:
& biomass

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-h EC50 was determined to be 9.77 mg/L (based in growth rate)
Executive summary:

The effect of the test item Morin was assessed on algal growth using the unicellular green alga Raphidocelis subcapitata (formerly known as Pseudokirchneriella subcapitata and Selenastrum capricornutum), over an exposure period of 72 hours.

Based on the results of a preliminary experiment, the calculated geometric mean test item concentrations (based on the analytical measurements) of 0.73, 1.04, 1.47, 19.21 and 53.68 mg/L were tested in the main study.

Exponentially-growing cultures of Raphidocelis subcapitata were exposed to the test item over several generations under defined conditions. The algal growth in relation to a control culture was determined over a fixed test period of 72 hours and, thus, over several algal generations. The test design included three replicates at each test concentration and six replicates for the untreated control. The alga cell concentration was approximately 104 cells/mL at the start of the test in all of the test cultures. Glass flasks with total capacity of 250 mL were used as test vessels. The volume of the test liquid in the vessels was 100 mL. The alga cell concentration was determined by microscope in each testing flask during the 72-hour test, in 24-hour intervals.

With respect to the inhibitory effect of the test item, the 0-72 h average specific growth rates and yield were significantly different from that of the control group in the concentrations of 1.47, 19.21 and 53.68 mg/L.

Accordingly the NOEC related to the average specific growth rates and yield was determined to be 1.04 mg/L and the LOEC was determined as 1.47 mg/L. The 72-h ErC50 was determined to be 9.77 mg/L and the 72-h EyC50 as 3.05 mg/L.