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:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

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

Test solutions

Vehicle:
not specified
Details on test solutions:
The primary stock solution used in the range-finding test was prepared by dissolving 0.0250 g of the test substance in 250 mL with OECD medium, resulting in a concentration of 100 mg.L-1. The stock solution of 1 mg.L-1 was prepared from dilution of the primary stock solution.
The primary stock solution used in the definitive test was prepared by dissolving 0.3200 g of the test substance in 1000 mL with OECD medium, resulting in a concentration of 320 mg.L-1. The stock solution of 100 mg.L-1 was prepared from dilution of the primary stock solution.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The unicellular green alga species Pseudokirchneriella subcapitata used is part of the Chloroficeae group, Chlorococcales order.

Study design

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

Test conditions

Test temperature:
22.3 to 22.4oC
Details on test conditions:
Temperature: 22.3 to 22.4oC
Light: 4716 lux (average)
Photoperiod: continuous light
Shaker velocity: 130 rpm (average)
Reference substance (positive control):
yes

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
other: EyC50
Effect conc.:
48.38 mg/L
Conc. based on:
test mat.
Basis for effect:
other: Yield
Key result
Duration:
72 h
Dose descriptor:
other: ErC50
Effect conc.:
191.82 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Results with reference substance (positive control):
The 72-hours EyC50 value of the reference substance potassium dichromate was 0.79 mg.L-1 (confidence limits at 95% = 0.72 to 0.85 mg.L-1), demonstrating that the toxic sensitivity of the algae was within the accepted range (ISO, 1989), which report toxicity ranged between 0.60 and 1.03 mg.L-1.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-hours EyC50 value for alga Pseudokirchneriella subcapitata exposed to (R)-3,7-dimethyl-1,6-octadien-3-ol was 48.38 mg.L-1 and the 72-hours ErC50 value was 191.82 mg.L-1. The highest test substance concentration with no observed significant adverse effect (NOEC) on algal growth was 10 mg.L-1 and the lowest test substance concentration at which was observed significant reducing effect on growth (LOEC) was 32 mg.L-1.