3,7-dimethyloctanal

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:

April 7, 2003 to August 18, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,7-dimethyloctanal

EC Number:

227-810-9

EC Name:

3,7-dimethyloctanal

Cas Number:

5988-91-0

Molecular formula:

C10H20O

IUPAC Name:

3,7-dimethyloctanal

Specific details on test material used for the study:

TEST MATERIAL
Name ( stated on the report) : TETRAHYDRO CITRAL
Appearance: Colourless to pale yellow liquid
Batch: 9000492013
Expiry date: May 12, 2003.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Fresh activated sludge from a biological waste water treatment plant treating predominantly domestic sewage (City of Geneva, Peney-Dessous) was used.
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):

35 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

other: Sodium benzoate (Fluka, Buchs, Switzerland, Art. No. 71300), purity : min. 99.0 %.

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

64

Sampling time:

28 d

Details on results:

Biodegradation starts on day 3 and reaches 51% at the end of the 10-day window (days 3 to 13).

BOD5 / COD results

Results with reference substance:

The curves obtained with the reference substance alone and with TETRAHYDRO CITRAL + reference substance show no toxic effect of TETRAHYDRO CITRAL to the micro-organisms at the test concentration (100 mg/l).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

TETRAHYDRO CITRAL undergoes 64% biodegradation after 28 days (67% after 35 days) in the test conditions. Biodegradation starts on day 3 and reaches 51% at the end of the 10-day window (days 3 to 13).
The curves obtained with the reference substance alone and with TETRAHYDRO CITRAL + reference substance show no toxic effect of TETRAHYDRO CITRAL to the micro-organisms at the test concentration (100 mg/l).

Executive summary:

The Ready Biodegradability of TETRAHYDRO CITRAL was determined by the Manometric Respirometry Test according to the OECD Guidelines for Testing of Chemicals, Method No. 301 F.

TETRAHYDRO CITRAL undergoes 64% biodegradation after 28 days (67% after 35 days) in the test conditions.

Biodegradation starts on day 3 and reaches 51% at the end of the 10-day window (days 3 to 13).

The curves obtained with the reference substance alone and with TETRAHYDRO CITRAL + reference substance show no toxic effect of TETRAHYDRO CITRAL to the micro-organisms at the test concentration (100 mg/l).