N,N''-(isobutylidene)diurea

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

78

Sampling time:

28 d

Details on results:

Following results were reported.

In the test vessels N remained as NH3 form and after the cultivation and extents of biodegradation were calculated using ThOD based on NH3.

Biodegradation rates (28 days)
---------------------------------------------
by BOD 77% 81% 77% (Av. 78%)
by DOC 89% 90% 90% (Av. 90%)
by HPLC100% 100% 100% (Av. 68%)
---------------------------------------------

Based on the BOD analysis, the 10-day window was fulfilled.

After the 28 days of cultivation, pH remained within the required range of 6.0 to 8.5.

Oxygen consumption of the blank vessels was 14.3 mg/l.

Kinetic of test substance (in %):
= 72 after 7 day(s)
= 78 after 14 day(s)
= 78 after 21 day(s)
= 78 after 28 day(s)

Degradation products: not measured

Results with reference substance:

Kinetic of control substance (in %):
= 60 after 7 day(s)
= 72 after 14 day(s)

Interpretation of results:

readily biodegradable

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Version / remarks:

1981

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Initial conc.:

19.6 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Reference substance:

other: not reported

Key result

Parameter:

% degradation (DOC removal)

Value:

85

Sampling time:

28 d

Details on results:

other: biodegradable, but not "readily biodegradable" according to OECD criteria (ready test pass level reached, but not the 10 day window)

Kinetic of test substance (in %):
= 8 ... 14 after 7 day(s)
= 24 ... 30 after 14 day(s)
= 48 ... 75 after 21 day(s)
= 78 ... 91 after 28 day(s)
Degradation products: not measured

Interpretation of results:

readily biodegradable, but failing 10-day window

Description of key information

Readily biodegradable (according to OECD criteria)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Two biodegradation tests on readily biodegradbility are available for IBDU. In a GLP study according to OECD guideline 301C, IBDU was degraded by 78% after 28 days (NITE 2002). The OECD criteria: 10 -day window and pass level >= 60% were fullfilled. Therefore, IBDU can be classified as readiliy biodegradable. This result is supported by a study from BASF AG (1988), where in a non GLP test according to Guideline 301 E, IBDU was degraded by 85% after 28 days. In this test, however, the OECD criteria of a 10 day window was not fullfilled and by thereby this result can only be used as additional information.