6-methyloct-5-en-2-one

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

Study period:

21.09.2007 - 31.01.2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD guideline under GLP

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

6-methyloct-5-en-2-one

EC Number:

246-073-4

EC Name:

6-methyloct-5-en-2-one

Cas Number:

24199-46-0

Molecular formula:

C9H16O

IUPAC Name:

6-methyloct-5-en-2-one

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

6.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

22 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 9.9 - 33

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 8.1 - 24

Any other information on results incl. tables

The mean measured test concentrations (calculated as the arithmetic mean over all measurements per test concentration) varied in the range of 59 to 73% of the nominal values. The reported biological results are based on the mean measured test item concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item had a statistically significant inhibitory effect on the growth (yield) of Pseudokirchneriella subcapitata after the test period of 72 hours atthe mean measured test concentrations of 6.2 mg/L and above . Thus, this test concentration was determined as the 72-hour LOEC (lowest
concentration tested with toxic effects). The growth rate µ was statistically significantly reduced first at the next higher test concentration of 13 mg/.
The 72-hour NOEC (highest concentration tested without toxic effects after a test period of 72 hours) was determined to be 3.4 mg/L, since up to
and including this test concentration the mean yield and the mean growth rate of the algae was not statistically significantly lower than in the control.

Executive summary:

The influence of the test item Ethylheptenone on the growth of the freshwater green algal species Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum) was investigated in a 72-hour static test according to the EU Commission Directive 92/69/EEC, C.3 (1992), and the OECD Guideline 201 (2006). The nominal test concentrations were 2.2, 4.6, 10, 22, 46 and 100 mg/L in parallel to a control. Since Ethylheptenone was considered to be volatile, the test was performed in a closed system to avoid losses of the test item by evaporation. At the start of the test, the measured test item concentrations in the analyzed test media ranged from 58 to 89% of the nominal values. At the end of the test, 52 to 75% of the nominal values were found. The reported biological results are based on the mean measured test item concentrations (calculated as the arithmetic mean over all measurements per test concentration).

The test item had a statistically significant inhibitory effect on the growth (yield) of Pseudokirchneriella subcapitata after the test period of 72 hours at the mean measured test concentrations of 6.2 mg/L and above (results of Dunnetts test). Thus, this test concentration was determined as the 72-hour LOEC (lowest concentration tested with toxic effects). The growth rate µ was statistically significantly reduced first at the next higher test concentration of 13 mg/L. The 72-hour NOEC (highest concentration tested without toxic effects after a test period of 72 hours) was determined to be 3.4 mg/L, since up to and including this test concentration the mean yield and the mean growth rate of the algae was not statistically significantly lower than in the control.