Cyclohexane, oxidized, aq. ext., sodium salt

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexane, oxidized, aq. ext., sodium salt

EC Number:

272-812-5

EC Name:

Cyclohexane, oxidized, aq. ext., sodium salt

Cas Number:

68915-39-9

Molecular formula:

Unspecified (UVCB substance)

IUPAC Name:

Cyclohexane, oxidized, aq. ext., sodium salt

Details on test material:

- Name of test substance: Natriumcarboxylat- Lösung
- Test substance No.: 09/0194-1
- CAS No.: 68915-39-9

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test solutions are prepared separately for each test concentration. For this the test substance was weighed in, made up with OECD medium and stirred for about 10 min at approximately 20 ± 2 °C to reach concentrations of 111% of the nominal concentration. To reach the correct nominal concentrations at test start, inoculum culture was added to each 111% stock test solution at a ratio of 1:10.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

-Test species and strain: Desmodesmus subspicatus CHODAT (SAG 86.81)
- Age (on study day 0): A stock algal culture is maintained continuously at the test facility. Before the exposure an inoculum culture is prepared from the stock culture and incubated for 3 days at 21 – 24 °C (max. temperature difference 2 °C). After this time, the inoculum culture is in exponential growth phase and can be used to initiate the test (study day 0).
- Supplier: Collection of algal cultures in University of Göttingen/Germany

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

pH:

8.0-8.6

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: Erlenmeyer flasks (nominal volume 250 mL) plugged with gas permeable silicone sponge caps
- Initial cells density: 0.5 x 104 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8
- Light intensity and quality: Average 4900 lux (within ±15% variability) at a wave length of 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 224.58 mg/L

Nominal / measured:

nominal

Conc. based on:

other: water-adjusted substance amount (53.6% water content)

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 484 mg/L

Nominal / measured:

nominal

Conc. based on:

other: not water-adjusted substance amount (53.6% water content)

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 21.34 mg/L

Nominal / measured:

nominal

Conc. based on:

other: water-adjusted substance amount (53.6% water content)

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes