4,4'-isopropylidenediphenyl dicyanate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March - September 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Test Substance Name: LZ 514
- Source: Lonza Ltd, Visp/Switzerland
- Lot/batch No. of test material: 5011
- Expiration date of the lot/batch: 2nd December 2017
- Manufacture date: 3rd December 2015

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage conditions: Controlled room temperature (15-25 ºC, below 70 RH%), protected from light and humidity.
- Stability under test conditions: stable
- Safety precautions: Routine safety precautions (lab coat, gloves, safety glasses, face mask) for unknown materials were applied to assure personnel health and safety.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Inoculum: secondary effluent, microorganisms from a domestic waste
- Source: domestic sewage in Veszprém, Hungar
- Conditioning: the secondary effluent used for this study was allowed to settle for 40 minutes, then the decanted effluent was aerated

Duration of test (contact time):

28 d

Initial conc.:

2.4 mg/L

Based on:

test mat.

Initial conc.:

6.072 mg/L

Based on:

other: ThODNO3

Parameter followed for biodegradation estimation:

DOC removal

Reference substance:

benzoic acid, sodium salt

Remarks:

concentration: 3.6 mg/l

Preliminary study:

14-day preliminary study

Key result

Parameter:

% degradation (DOC removal)

Value:

15.6

Sampling time:

7 d

Key result

Parameter:

% degradation (DOC removal)

Value:

16.5

Sampling time:

14 d

Key result

Parameter:

% degradation (DOC removal)

Value:

20.6

Sampling time:

21 d

Key result

Parameter:

% degradation (DOC removal)

Value:

14

Sampling time:

28 d

Details on results:

The test item was not considered to be have significant inhibitory effects on the secondary effluent microorganisms.

Results with reference substance:

Percent of biodegradation of reference item sodium benzoate:
- 7 days: 73.3%
- 14 days: 77.5%
- 21 days: 82.5%
- 28 days: 83.3%

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The percentage biodegradation of the test item reached a mean of 14.0 % after 28 days based on the ThODNO3 of the test item.The test item was not considered to be have significant inhibitory effects on the secondary effluent microorganisms. Based on the results of this study, the test item is considered not readily
biodegradable.

Executive summary:

The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days, in accordance with EC-method C.4-E. Inoculum was activated sludge from a domestic sewage treatment plant. Sodium benzoate was used as reference substance. The percentage biodegradation of the test item reached a mean of 14.0 % after 28 days based on the ThODNO3 of the test item.The test item was not considered to be have significant inhibitory effects on the secondary effluent microorganisms. Based on the results of this study, the test item is considered not readily biodegradable.

Description of key information

The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days, in accordance with EC-method C.4-E. Inoculum was activated sludge from a domestic sewage treatment plant. Sodium benzoate was used as reference substance. The percentage biodegradation of the test item reached a mean of 14.0 % after 28 days based on the ThODNO3 of the test item.The test item was not considered to be have significant inhibitory effects on the secondary effluent microorganisms. Based on the results of this study, the test item is considered not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Source: GLP-report