Octanal, 7-hydroxy-3,7-dimethyl-, reaction products with 1H-indole

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

η-1H-indol-3-yl-α,α,ε-trimethyl-1H-indole-3-heptanol

EC Number:

267-434-2

EC Name:

η-1H-indol-3-yl-α,α,ε-trimethyl-1H-indole-3-heptanol

Cas Number:

67860-00-8

Molecular formula:

C26H32N2O

IUPAC Name:

8,8-di(1H-indol-3-yl)-2,6-dimethyloctan-2-ol

Constituent 2

Reference substance name:

Indole

EC Number:

204-420-7

EC Name:

Indole

Cas Number:

120-72-9

Molecular formula:

C8H7N

IUPAC Name:

1H-indole

Constituent 3

Reference substance name:

7-hydroxycitronellal

EC Number:

203-518-7

EC Name:

7-hydroxycitronellal

Cas Number:

107-75-5

Molecular formula:

C10H20O2

IUPAC Name:

7-hydroxy-3,7-dimethyloctanal

Constituent 4

Reference substance name:

1-(1H-indol-1-yl)-3,7-dimethyloctane-1,7-diol

Cas Number:

1642782-49-7

Molecular formula:

C18H27NO2

IUPAC Name:

1-(1H-indol-1-yl)-3,7-dimethyloctane-1,7-diol

Constituent 5

Reference substance name:

Unknown constituents

IUPAC Name:

Unknown constituents

Specific details on test material used for the study:

Commercial Name: Indolene
CAS Number: 68908-82-7
Appearance: green to yellow viscous liquid
Lot No.: 9000339929

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, Aire) was used.
The sludge was 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):

29 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

Details on study design:

A measured volume of inoculated mineral medium, containing a known concentration of test substance (100 mg/l) as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature of 2 2°C (+/- 1 °C) for up to 28 or 29 days. The consumption of oxygen is determined by measuring the quantity of oxygen (produced electrolytically) required to maintain constant the gas volume in the respirometer flask. Evolved carbon dioxide was absorbed in soda lime pellets. The Biological Oxygen Demand (BOD), amount of oxygen taken up by the microbial population during biodegradation of the test chemical (corrected for uptake by blank inoculam, run in parallel) was expressed as a percentage of ThOD (Theoretical Oxygen Demand, calculated from the elemental composition, assuming that carbon is oxidised to carbon dioxide and hydrogen to water).

Reference substance

Reference substance:

other: Sodium Benzoate

Remarks:

NaBenzoate used as ref substance : 100 mg/L NaBenzoate + 30 mg/L inoculum.

Results and discussion

Test performance:

Everyday the oxygen consumption of each flask was recorded and correct temperature and stirring were checked.
At the end of the test period, the pH of each flask was measured.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

76

Sampling time:

28 d

Details on results:

Under the test conditions, the test item was deteremined to be READILY BIodegradable, fulfiling the 10-day window criteria (Day 2 = 22% biodegradation, Day 12 = 63% biodegradation). INDOLENE can, therefore, be considered as READILY Biodegradable.

BOD5 / COD results

Results with reference substance:

Degradation of sodium benzoate exceeds 40% after 7 days and 65% after 14 days: the activity of the inoculum is thus verified and the test is considered as valid.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Indolene undergoes 76% biodegradation after 28 days (also 76% after 29 days) under the test conditions. Biodegradation starts on day 2 and reaches 63% at the end of the 10-day window (days 2 to 12).
Thus, Indolene should be regarded as readily biodegradable, fulfilling the 10-d window criterion, according to this test.
The curves obtained with the reference substance alone and with Indolene + reference substance show no toxic effect of Indolene to the micro-organisms at the test concentration.

Executive summary:

INDOLENE is READILY Biodegradable, fulfilling the 10-day window criterion.