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:
other: GLP guideline study with analytical monitoring

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Tridecanol A
- Physical state: liquid/colourless-clear
- Analytical purity: 99.95%

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 3.13; 12.5 and 100 mg/L after 0 h and 72 h analyzing the uninoculated replicates

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solution was prepared for each concentration. The stock solutions were stirred in demineralised water for about 20 h at approximately 20 ± 2 °C. Undissolved test substance was removed by centrifugation for ca. 20 min at ca. 17700 G.
- Differential loading: yes

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: green algae
- Strain: SAG 86.81
- Source: Algae collection Goettingen

Study design

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

Test conditions

Nominal and measured concentrations:
Nominal test concentrations: control, 3.13, 6.25, 12.5, 25, 50, 100 mg/L
Measured test concentrations (0 h): < 0.1, 2.8, 3.8, 5.6 mg/L
Measured test concentrations (72 h): < 0.1, 0.2, 0.2, 1.3 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, nominal volume, fill volume: Erlenmeyer flasks plugged with permeable siliconsponge caps, 250 ml, 100 ml
- Initial cells density: 10000 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Test medium: according to EEC Directive 92/69/EEC, Annex V, Part C .3
- Intervals of water quality measurement: Temperature continuously during the whole test period in the climate chamber, pH after 0 h and 72 h in an additional uninoculated replicate and after 72 h in the inoculated replicate No. 1 of each concentration.

OTHER TEST CONDITIONS
- Photoperiod: permanent illumination
- Light intensity and quality: artificial light, type universal white (OSRAM L 25), about 60 - 120 µE/(m2*s) at a wave length of 400 - 700 nm

EFFECT PARAMETERS MEASURED: Biomass and growth rate after 24, 48, 72 h
- Determination of cell concentrations: after 72 h in a counting chamber (Neubauer improved) in replicate No. 2 of the inoculated control
- Chlorophyll measurement: in vivo chlorophyll-a-fluorescence (pulsed excitation with light flashes having a wavelength of 435 nm) after 0, 24, 48 and 72 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2


Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
2.02 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
3.15 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
> 3.45 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
2 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
< 1.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.27 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
3.36 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
< 1.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
- Validity criteria: Cell multiplication in untreated controls after 72 h was 111 fold
Reported statistics and error estimates:
The EC values are calculated (linear regression analysis) from the concentration-response relationship.

Any other information on results incl. tables

Inhibition of algal biomass and growth rate after 72 h:
Biomass Growth rate
mg/L relative % relative %
0 2480 - 0.065 -
100 182 92.7 0.027 58.2
50 289 88.4 0.034 47.9
25 556 77.6 0.040 39.0
12.5 1553 37.4 0.059 9.2
6.25 1518 38.8 0.059 9.7
3.13 2015 18.8 0.062 3.8


The respective results on basis of nominal concentrations:
Effect on biomass (72 h):
EbC10 < 3.13 mg/L
EbC50 = 15.5 mg/L
EbC90 = 65.1 mg/L
NOEbC < 3.13 mg/L

Effect on growth rate (72 h):
ErC10 = 12.7 mg/L
ErC50 = 57.7 mg/L
ErC90 > 100 mg/L
NOErC = 12.5 mg/L


Applicant's summary and conclusion