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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study, with acceptable restrictions (e.g. non-GLP, no analytical verification of test item concentrations).

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report date:
2006

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: German Standard DIN 38412, Part 9
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2-ethylhex-2-enal
EC Number:
211-448-3
EC Name:
2-ethylhex-2-enal
Cas Number:
645-62-5
Molecular formula:
C8H14O
IUPAC Name:
2-ethylhex-2-enal
Details on test material:
- Name of test material (as cited in study report): 2-Ethylhexen-2-al

Sampling and analysis

Analytical monitoring:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: Scenedesmus subspicatus (renamed to Desmodesmus subspicatus)
- Strain: SAG 86.81

Study design

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

Test conditions

Test temperature:
20 °C
Nominal and measured concentrations:
Nominal test concentrations: 0 (control), 3.91, 7.81, 15.63, 31.25, 62.5, 125, 250 mg/l
Details on test conditions:
TEST SYSTEM
- Test vessel: 20 ml glass tubes with flat bottom, plugged with siliconesponge caps, 10 ml test volume
- Fill volume: 100 ml
- Initial cells density: 10000 cells/ml
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 2 blanks per concentration (w/o cells)


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to DIN 38412, part 9; OECD medium


OTHER TEST CONDITIONS
- Photoperiod: continuous white light
- Light intensity and quality: 220/70 µEinstein above/below the test vessels

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Chlorophyll measurement: in vivo chlorophyll-a-fluorescence at 685 nm wavelength (as measure for cell number): after 0, 24, 48 72, and 96 h

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
62.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
125 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
9.25 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
13.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
27.71 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

Any other information on results incl. tables

RS-Freetext:
The following nominal effect concentrations related to yield
(EyC), growth rate (ErC), and biomass integral (EbC) were
recalculated according to OECD TG 201 (adopted 23 Mar 2006)
using the fluorescence values for inhibition of biomass from
the original report. Since no calibration curve data were
available, fluorescence data were equated with cell numbers
(95 % confidence intervals in brackets):


Yield (mg/l)
------------------
72 h 96 h
EyC10: 5.71 (5.11-6.26) 6.95 (5.56-8.10)
EyC20: 7.61 (7.00-8.18) 8.95 (7.60-10.06)
EyC50: 13.17 (12.48-13.90) 14.49 (13.26-15.82)

NOEyC: 3.91 3.91
LOEyC: 7.81 7.81


Growth rate (mg/l)
------------------
72 h 72 h
ErC10: 9.25 (6.38-11.62) 10.83 (4.72-15.68)
ErC20: 13.50 (10.29-16.30) 15.41 (8.51-20.64)
ErC50: 27.71 (23.96-32.06) 30.18 (23.08-39.46)

NOErC: 62.50 62.50
LOErC: 125.00 125.00


Biomass integral (mg/l)
-----------------------
72 h 96 h
EbC10: 5.55 (4.73-6.30 6.23 (5.42-6.96)
EbC20: 7.54 (6.70-8.30 8.22 (7.40-8.96)
EbC50: 13.51 (12.62-14.47 13.92 (13.06-14.83)

NOEbC: 3.91 3.91
LOEbC: 7.81 7.81


Original effect values as given in the report
(nominal concentrations in mg/l):
72 h 96 h
EC20: 7.59 8.52
EC50: 13.8 15.3
EC90: 40.6 29.8


pH at test start (0 h) and at test end (72 h)
---------------------------------------------
stock solution (500 mg/l): pH 4.64 (conductivity: 15 µS/cm)

uninoculated inoculated
0 h 72 h 0 h 72 h
0 (control) 8.2 8.5 8.2 9.7
3.91 8.0 8.4 8.0 10.0
7.81 7.9 8.3 7.9 10.1
15.63 7.8 8.3 7.8 10.2
31.25 7.7 8.2 7.7 8.1
62.5 7.6 8.1 7.7 8.0
125 7.3 7.8 7.7 8.1
250 7.0 7.5 7.7 8.1



Applicant's summary and conclusion