5-cyclohexadecen-1-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:

Study Plan Signed 21 January 1997 - Final Report emission 27 February 1997; Experimental Phase : 21 January 1997 to 19 February 1997.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(E)-cyclohexadec-5-enone

Cas Number:

35951-24-7

Molecular formula:

C16H28O

IUPAC Name:

(E)-cyclohexadec-5-enone

Constituent 2

Reference substance name:

(Z)-cyclohexadec-5-enone

Cas Number:

21944-95-6

Molecular formula:

C16H28O

IUPAC Name:

(Z)-cyclohexadec-5-enone

Specific details on test material used for the study:

Name (as stated in the report): Ambretone
Batch: 261997

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

The sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 1000 g for 10 minutes, discarding the supernatant and resuspending in mineral medium) and kept aerobic until being used on the same day.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

other: nominal test substance concentration

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

other: Sodium benzoate

Remarks:

99% purity

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

86

Sampling time:

28 d

Details on results:

Oxygen uptakes, as read on the SAPROMAT meters are corrected:
- by deducting the basic oxygen uptake of sludge blank samples (Flasks 2/3 and 2/4)
- proportionally to account for the differences between actual and nominal concentrations of test and reference substance

BOD5 / COD results

Results with reference substance:

Degradation of Sodium Benzoate exceeds 40% after 7 days and 65% after 14 days (observed 72% biodegradation on Day 7 and 83% on Day 14): the activity of the inoculum is thus verified and the test is considered valid.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Ambretone undergoes 86% biodegradation after 28 days in the test conditions. Biodegradation starts (exceeds 10%) on day 3 (11% biodegradation) and reaches 72% at the end of the 10-day window (days 3 to 13).
Thus, Ambretone should be regarded as readily biodegradable according to this test.
The curves obtained with the reference substance alone and with Ambretone + reference substance show no toxic effect of Ambretone on the micro-organism at the test concentration.

Executive summary:

The Ready Biodegradability of Ambretone was determined by the Manometric Respirometry Test according to the OECD guideline 301F.

Ambretone undergoes 86% biodegradation after 28 days in the test conditions. Biodegradation starts (exceeds 10%) on day 3 (11%) and reaches 72% at the end of the 10-day window (days 3 to 13).

Thus, Ambretone should be regarded as readily biodegradable according to this test.

At the concentration used in the test (100 mg/L), Ambretone is not inhibitory to the micro-organisms.