Urea,N'-[3-[[[(dimethylamino)carbonyl]amino]methyl]-3,5,5-trimethylcyclohexyl]-N,N-dimethyl-

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

08/2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE:
- EPI Suite

2. MODEL (incl. version number):
- BIOWIN (v4.10)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
- Smiles: O=C(N(C)C)NC1CC(C)(C)CC(CNC(=O)(N(C)C))(C)C1
- Formular: C16 H32 N4 O2
- Mol WT: 312.46
- Strukture: see ch 1.1 "Identification"

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
[Explain how the model fulfils the OECD principles for (Q)SAR model validation. Consider attaching the QMRF or providing a link]
- Defined endpoint: Biodegradability
- Unambiguous algorithm:
- Biowin1 (Linear Model Prediction)
- Biowin2 (Non-Linear Model Prediction)
- Biowin3 (Ultimate Biodegradation Timeframe)
- Biowin4 (Primary Biodegradation Timeframe)
- Biowin5 (MITI Linear Model Prediction)
- Biowin6 (MITI Non-Linear Model Prediction)
- Biowin7 (Anaerobic Model Prediction)
- Defined domain of applicability: na
- Appropriate measures of goodness-of-fit and robustness and predictivity: na
- Mechanistic interpretation: na

5. APPLICABILITY DOMAIN
[Explain how the substance falls within the applicability domain of the model]
- Descriptor domain: na
- Structural and mechanistic domains:
- Carbon with 4 single bonds and no hydrogens
- Molecular weight parameter (Biowin 1 - 6)
- Methyl [-CH3] (Biowin 5 - 7)
-CH2- [linear] (Biowin 5 - 7)
-CH2- [cyclic] (Biowin 5 - 7)
-CH- [cyclic] (Biowin 5 - 7)
- Equation Constant (Biowin 1 - 6)
- Similarity with analogues in the training set: na
- Other considerations (as appropriate): na

6. ADEQUACY OF THE RESULT
[Explain how the prediction fits the purpose of classification and labelling and/or risk assessment]

Qualifier:

no guideline required

Principles of method if other than guideline:

QSAR

GLP compliance:

not specified

Key result

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Value:

< 0.5

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Remarks:

Biowin 1 - 7

Biowin1 (Linear Model Prediction)   : Does Not Biodegrade Fast

Biowin2 (Non-Linear Model Prediction): Does Not Biodegrade Fast

Biowin3 (Ultimate Biodegradation Timeframe): Months

Biowin4 (Primary Biodegradation Timeframe): Weeks

Biowin5 (MITI Linear Model Prediction)   : Does Not Biodegrade Fast

Biowin6 (MITI Non-Linear Model Prediction): Does Not Biodegrade Fast

Biowin7 (Anaerobic Model Prediction): Does Not Biodegrade Fast

Ready Biodegradability Prediction: NO

 

Conclusions:

Based on QSAR prediction, IPDI-Uron does not biodegrade fast.

Executive summary:

Based on QSAR prediction, IPDI-Uron does not biodegrade fast.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03/2017 - 06/2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

The higher NaOH concentration is based on years of experience and ensures that the carbon dioxide produced is actually absorbed to the sodium hydroxide completely (see deviations from guideline).

Deviations:

yes

Remarks:

NaOH concentration used for CO2-Absorption in the gas wash bottles is higher (0.2 M) than indicated in the guidelline (0.05 M).

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch: 703709
Purity: 100 %
CoA: 2017-02-15

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Activated sludge from the municipal wastewater treatment plant Breisgauer Bucht was used as
inoculum with a concentration corresponding to 30 mg dry solids per litre. The treatment plant
clarifies predominantly domestic wastewater and has a capacity of 600.000 inhabitant
equivalents. Sampling date of activated sludge was on 03 April 2017. The dry solid content of the
activated sludge was 5.09 g/L. It was determined by weight measurements after drying at 105°C
for 4 hours (mean of triplicate measurements). The activated sludge was washed twice with tap
water by settling the sludge, decanting the supernatant and re-suspending the sludge.

Duration of test (contact time):

ca. 28 d

Initial conc.:

>= 19.8 - <= 19.9 mg/L

Based on:

TOC

Initial conc.:

>= 48.2 - <= 48.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

inorg. C analysis

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

ca. 0.3

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item did not reach the criteria for ready biodegradability (60% of ThCO2 within a 10-d window).

Executive summary:

No degradation of the test item could be measured during the test duration. The mean

degradation extent at the end of the test was -0.3%.

The degradation extent in the toxicity control was 47.8% within 14 days, the test substance had

no inhibitory effect on the inoculum.

The reference compound sodium benzoate reached the pass levels for ready biodegradability

within 4 days.

The mean CO2-evolution of the blank flasks was 32.0 mg/L on day 28 after acidification.

Description of key information

Ready biodegradability was assessed by modified Sturm test (OECD 301B, CO₂ evolution test) and calculated by QSAR (EPI Suite, Biowin 4.10).

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Additional information

QSAR calculation showed that the test item will not degrade fast.