2-ethylhex-2-enal

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

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Reference 2

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

Test material information

Constituent 1

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 concentrations

Effect concentrations 1

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

Effect concentrations 2

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

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

Effect concentrations 4

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

Effect concentrations 5

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