Cyclohexyl phenyl ketone

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:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD Series on Testing and Assessment No. 23

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexyl phenyl ketone

EC Number:

211-923-5

EC Name:

Cyclohexyl phenyl ketone

Cas Number:

712-50-5

Molecular formula:

C13H16O

IUPAC Name:

cyclohexyl(phenyl)methanone

Details on test material:

- Name of test material (as cited in study report): Cyclohexylphenylketone
- Physical state: melt, yellowish solid
- Analytical purity: 96.1 area-%
- Batch No.: 090713V104
- Storage condition of test material: The test substance was stored at ambient temperature

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling was performed at the start of the exposure (0 h) from the inoculated replicate 7 of each concentration and the control.
- At the end of the exposure (72 h) samples of the inoculated replicates 1-3 of the test concentrations and of the inoculated replicates 1- 6 of the control group were taken.
- The replicates were combined before sampling.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The saturated stock test solution was prepared by adding 200.09 mg of test substance in 2 L of test medium (100 mg/L loading concentration) and stirring for about one day to ensure that the saturation concentration was reached. Undissolved test substance was removed by filtration with a membrane filter (pore width 0.2 μm). The lower test concentrations were prepared by dilution of this stock solution.
All stock test solutions appeared colorless and clear.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: SAG 86.81
- Source: Collection of algal cultures in University of Göttingen, Germany
- Age of inoculum (at test initiation): 3 days

CULTURE CODITIONS
An inoculum culture in exponential growth phase was prepared with an aliquot of the stock algal culture added to sterile test media to provide an initial cell density of 0.5E+04 cells/ml. The inoculum culture is incubated under test conditions for 3 days prior to test initiation. The increase in biomass is verified to ensure that growth is within the normal range and algal cells are examined microscopically for normal morphology prior to use for test inoculation.
- Inoculum culture cell density (3 days growth): 54E+04 cells/mL (108 fold increase)
- Inoculum culture morphology: normal and healthy

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

23 - 23.3 °C

pH:

7.9 - 8.3

Nominal and measured concentrations:

Control, 10%, 18%, 32%, 56%, 100% as nominal dilutions of a saturated solution of the test substance in test media
Control, 0.98, 1.69, 3.08, 5.56, 9.20 mg/L as mean analytically measured concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, nominal volume, fill volume: Erlenmeyer flasks plugged with gas permeable silicone sponge caps, 250 ml, 100 ml / 200 ml for replicate 0 and 7
- Initial cells density: 0.5E+04 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The test medium was prepared according to OECD Guideline for Testing of Chemicals,
No. 201
- Intervals of water quality measurement: pH in one uninoculated replicate and one inoculated replicate at study initiation and in all replicates at study end. Temperature was continuously measured during the whole test period in the climate chamber in a flask with deionized water

OTHER TEST CONDITIONS
- Illumination: artificial light, type universal white (OSRAM L 25), permanent illumination
- Light intensity: average 5015 lux (within ± 15% variability) at a wave length of 400 - 700 nm

EFFECT PARAMETERS MEASURED: algal growth
- Determination of cell concentrations: counting chamber (two counts in a Neubauer haemocytometer)
- Chlorophyll measurement: in vivo chlorophyll-a fluorescence (pulsed excitation with light flashes having a wavelength of 432 nm) after 0, 24, 48, 72 hours
- Algal morphology: The inoculum culture was observed microscopically at the start of the test to verify normal and healthy cells. At testtermination, a pooled sample from each test concentration was examined and any abnormal appearance of the algae was noted

TEST CONCENTRATIONS
- Spacing factor for test concentrations: <= 3.2
- Range finding study: yes
- Test concentrations: EfC50 = 7.6 mg/L; ErC50 = 8.0 mg/L (nominal)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.52 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.48 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

7.77 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.69 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.65 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3.77 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 7

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

5.26 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 8

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.69 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: yield