6,8-dimethylnona-3,5-dien-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:

09/2002 - 10/ 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study performed according to OCED and GLP guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

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:

-

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

6,8-dimethylnona-3,5-dien-2-one

EC Number:

274-446-1

EC Name:

6,8-dimethylnona-3,5-dien-2-one

Cas Number:

70214-76-5

Molecular formula:

C11H18O

IUPAC Name:

6,8-dimethylnona-3,5-dien-2-one

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 100 mg/L

Based on:

ThOD/L

Results and discussion

% Degradation

Parameter:

% degradation (DOC removal)

Value:

ca. 62

Sampling time:

28 d

Details on results:

-

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

DIMETHYLNONADIENON did not reach the pass level of 60 % for ready biodegradability in the
Manometric Respirometry Test within the 10-d window and, therefore, cannot be termed as readily
biodegradable. However, the pass level of 60 % was reached within 28 days. The material is therefore
expected to degrade rapidly in the environment

Executive summary:

The biodegradability of DIMETHYLNONADIENON exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions. The biodegradability of DIMETHYLNONADIENON based on O2 consumption was calculated to be 62 % after 28 days as compared to the theoretical oxygen demand (ThOD). The biodegradation of DIMETHYLNONADIENON reached 53 % at the end of the 1 O-d window. Biodegradation of the test substance was observed after a lag phase of about 5 days. The procedure control sodium benzoate reached 85 % biodegradation after 14 days, thus confirming suitability of inoculum and test conditions. The calculated biodegradation based on DOC measurement reached 98 % for DIMETHYLNONADIENON and 100 % for sodium benzoate. The data show that the consumed O2 was used for partial mineralization of the test compound, since the determined degradation values based on BOD were lower as compared to those based on DOC. DIMETHYLNONADIENON did not reach the pass level of 60 % for ready biodegradability in the Manometric Respirometry Test within the 10-d window and, therefore, cannot be termed as readily biodegradable. However, the pass level of 60 % was reached within 28 days. The material is therefore expected to degrade rapidly in the environment.