4-methylmorpholine

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: sediment simulation testing

Data waiving:

other justification

Justification for data waiving:

other:

Transformation products:

no

Reference 2

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

June 2021

Reliability:

1 (reliable without restriction)

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
CATALOGIC 301C model for predicting biodegradability of chemicals

2. MODEL (incl. version number)
CATALOGIC 301C v.11.16

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See attached QPRF

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
The algorithm of the model reflects the current understanding of the process by which microorganisms degrade organic chemicals. Rule based simulator accounting for metabolic logic of microbial catabolism generates a detailed catabolic multipathway map for the target chemical. Based on the simulated catabolism the material balance equations are extracted and used to predict the consumption of oxygen and quantities of metabolites. The prediction of primary and ultimate half-lives is based on the assumption that biodegradation process follows first order kinetic.
Further details can be found in the attached QMRF.

5. APPLICABILITY DOMAIN
The applicability domain of CATALOGIC 301C model contains 3 layers.
- General properties requirements. These requirements specify in the domain only those chemicals that fall in the range of variation of physicochemical properties that may affect significantly the quality of the measured endpoint. For CATALOGIC 301C model attention is focused on lipophilicity (log KOW), molecular weight (MW) and water solubility (WS). Only correctly predicted chemicals from the training set are used to determine the range of variation of these properties.
- Structural domain. It determines the maximum structural similarity between the target chemical and chemicals from the training set. The structural neighborhood of atom-centered fragments (ACF) accounting for first neighbours or 3 heteroatoms, atom type, hybridization and attached hydrogen atoms are used to determine this similarity. A chemical belongs to the structural domain of the model if it could be partitioned only on correct fragments.
- Metabolic domain. It takes into account how successful was the simulator to simulate the full microbial mineralization of the target chemical. In case the full mineralization is not achieved, it is assumed that the prediction of catabolism is failed.
More information on the model's applicability domain can be found in the attached QMRF and QPRF.

6. ADEQUACY OF THE RESULT
The results are considered appropriate to fulfil the REACH requirements for identification of degradation products (Annex IX, SEction 9.2.3). The compounds meet the criteria for applicability of the CATALOGIC 301C model. More information on this can be found in the attached QPRF.

Guideline:

other: REACH guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: CATALOGIC 301C
- Model(s) used: CATALOGIC 301C model v.11.16
- Model description: see field 'Justification for non-standard information', see attached QMRF
- Justification of QSAR prediction: see field 'Justification for type of information', see attached QPRF

GLP compliance:

no

Specific details on test material used for the study:

SMILES codes for calculation: see attached QPRF

Oxygen conditions:

aerobic

Inoculum or test system:

other: model calculation

Parameter followed for biodegradation estimation:

other:

Key result

Remarks on result:

other: of the 6 potential metabolites of the substance predicted with the CATALOGIC 301C model, 4 were determined to be readily biodegradable and 2 were determined to be not readily biodegrable

Transformation products:

not specified

Degradation products identified with the CATALOGIC 301C model, including log Kow and biodegradation properties.

 

Substance	Smiles code	CAS number	Quantity (mol/mol parent)	log Kow	BOD prediction (after 28 days)	PBT assessment
Parent compound	CN1CCOCC1	109-02-4	0.8581	-0.32	3%	not PBT/vPvB
Metabolite #1	C1CNCCO1	110-91-8	0.1058	-0.559	1%	not PBT/vPvB
Metabolite #2	OCN1CCOCC1		0.03498	-1.813	3%	not PBT/vPvB
Metabolite #3	OCNCCOCC=O		0.0005517	-2.91	84%	not PBT/vPvB
Metabolite #4	NCCOCC=O		0.0005487	-1.911	71%	not PBT/vPvB
Metabolite #5	OC=O	64-18-6	0.0003678	-0.4605	100%	not PBT/vPvB
Metabolite #6	C=O	50-00-0	0	0.35	100%	not PBT/vPvB

 

Validity criteria fulfilled:

yes

Conclusions:

The relevant degradation products of 4-methylmorpholine were identified by means of the CATALOGIC 301C model. These degradation products were then assessed for their P, B and T properties in view of the PBT/vPvB assessment. Six degradation products were predicted. Two of these degradation products were predicted in quantities > 0.001 mol/mol parent compound, and identified as not readily biodegradable but with log Kow <3, concluding they are neither PBT nor vPvB. The remaining four degradation products were predicted in quantities < 0.001 ml/mol parent compound, and identified as readily biodegradable and with log Kow <3, concluding they are neither PBT nor vPvB. In conclusion, none of degradation products predicted with the CATALOGIC 301C model are concluded to be PBT or vPvB substances.

Description of key information

A QSAR exercise was completed for the endpoint coverage. The relevant degradation products of 4-methylmorpholine were identified by means of the CATALOGIC 301C model. These degradation products were then assessed for their P, B and T properties in view of the PBT/vPvB assessment. Six degradation products were predicted. Two of these degradation products were predicted in quantities > 0.001 mol/mol parent compound, and identified as not readily biodegradable but with log Kow <3, concluding they are neither PBT nor vPvB. The remaining four degradation products were predicted in quantities < 0.001 ml/mol parent compound, and identified as readily biodegradable and with log Kow <3, concluding they are neither PBT nor vPvB. In conclusion, none of degradation products predicted with the CATALOGIC 301C model are concluded to be PBT or vPvB substances.