6-methyloct-5-en-2-one

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02.07. - 26.11.2007

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:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry 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

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

58

Sampling time:

28 d

Details on results:

The percent biodegradation of the test item was calculated based on the theoretical oxygen demand (ThOD) of 2.85 mg 02/mg test item.
The biochemical oxygen demand (BOD) of Ethylheptenone Technical in the test media
significantly increased from about Exposure Day 3 until test termination after 28 days. At the
end of the 28-day exposure period, the mean biodegradation of Ethylheptenone Technical amounted to 59%.
Therefore, Ethylheptenone Technical was found to be biodegradable under the test
conditions within 28 days. However, the pass level for ready biodegradability, i.e.
biodegradation of at least 60% of the ThOD in a 10-day window within the 28-day period of the test, was not reached.
Consequently, Ethylheptenone Technical was not readily biodegradable under the test conditions within 28 days.

BOD5 / COD results

Results with reference substance:

In the procedure controls, the reference item was degraded by an average of 87% by
Exposure Day 14, thus confirming suitability of the activated sludge. At the end of the test
(Day 28), the reference item was degraded by an average of 90%.

Any other information on results incl. tables

No other information

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: biodegradable, the pass level for ready biodegradability was not reached

Conclusions:

At the end of the 28-day exposure period, the mean biodegradation of Ethylheptenone Technical amounted to 59%. Consequently, Ethylheptenone Technical was found to be biodegradable under the test conditions within 28 days. However, the pass level for ready biodegradability, i.e. biodegradation of at least 60% of the ThOD in a 10-day window within the 28-day period of the test, was not reached.

Executive summary:

The test item Ethylheptenone Technical was investigated for its ready biodegradability in a manometric respirometry test over 28 days according to EU Commission Directive 92/69 EEC, C.4-D (1992) and OECD Guideline for Testing of Chemicals No. 301 F (1992). The percent biodegradation of the test item was calculated based on the theoretical oxygen demand (ThOD) of 2.85 mg Odmg test item. The biochemical oxygen demand (BOD) of Ethylheptenone Technical in the test media significantly increased from about Exposure Day 3 until test termination after 28 days. At the end of the 28-day exposure period, the mean biodegradation of Ethylheptenone Technical amounted to 59%. Consequently, Ethylheptenone Technical was found to be biodegradable under the test conditions within 28 days. However, the pass level for ready biodegradability, i.e. biodegradation of at least 60% of the ThOD in a 10-day window within the 28-day period of the test, was not reached. In the toxicity control, containing both Ethylheptenone Technical and the reference item sodium benzoate, Ethylheptenone Technical had no inhibitory effect on the activity of activated sludge microorganisms at the tested concentration of 101 mg/L. In the procedure controls, the reference item sodium benzoate was degraded by an average of 87% by Exposure Day 14, and reached an average biodegradation of 90% by the end of the test (Day 28), thus confirming suitability of the activated sludge.