4-isopropylbenzonitrile

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:

2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant study conducted according to OECD Guidelines, with no or minor deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-isopropylbenzonitrile

EC Number:

237-492-3

EC Name:

4-isopropylbenzonitrile

Cas Number:

13816-33-6

Molecular formula:

C10H11N

IUPAC Name:

4-(propan-2-yl)benzonitrile

Test material form:

other: Liquid

Details on test material:

Batch NX00002996
Purity 98.4%
Expiry Date 23.02.2012

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

90 d

Initial test substance concentration

Initial conc.:

30 mg/L

Based on:

test mat.

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

>= 10

Sampling time:

8 d

Remarks on result:

other: Flask 5

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

78

Sampling time:

28 d

Remarks on result:

other: Flask 5

% Degradation 3

Parameter:

% degradation (O2 consumption)

Value:

>= 10

Sampling time:

27 d

Remarks on result:

other: Flask 6

% Degradation 4

Parameter:

% degradation (O2 consumption)

Value:

20

Sampling time:

28 d

Remarks on result:

other: Flask 6

Details on results:

Flask 5 : %Degr 94% after 60 days and 101% after 90 days
Flask 6: %Degr 87% after 60 days and 104% after 90 days

Any other information on results incl. tables

Cumin Nitrile did not significantly inhibit the intrinsic respiration of the inoculum at the test concentration and was therefore considered to be non-toxic to the inoculum at the test concentration.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not Readily biodegradable but inherently and Ultimately Biodegradable.

Conclusions:

The two replicates showed different behaviour. In one test flask biodegradation started on day 8 and reached 78% after 28 days (i.e. passing the readily biodegradability criteria). However, in the other flask the onset of biodegradation was delayed, starting on day 27 and thus only achieving 20% after 28 days. Since the average biodegradation of the two replicates at 28 days was < 60%, Cumin Nitrile should be regarded as not readily biodegradable according to this test.
The test was prolonged and both replicates achieved high levels of degradation (i.e. 87% and 94% after 60 days; 101% and 104% after 90 days). Based on these results Cumin Nitrile should be regarded as inherently and ultimately biodegradable.