Bis(1-n-butyl-3-methylcyclopentadienyl)zirconium dichloride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

SOFTWARE: EPISuite v4.11
MODEL (incl. version number): BIOWIN v4.10
SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: CCCCC1=CC(C)=CC1[Zr](Cl)(Cl)C1CC(C)=CC=1CCCC
SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL & APPLICABILITY DOMAIN: see attached justification
ADEQUACY OF THE RESULT: Acceptable, since biodegradability predictions show limited potential for biodegradability, the QSAR states 'not readily biodegradable', which is consistent with the metallocene chemistry.

1. SOFTWARE

2. MODEL (incl. version number)

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

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:
- Unambiguous algorithm:
- Defined domain of applicability:
- Appropriate measures of goodness-of-fit and robustness and predictivity:
- Mechanistic interpretation:

5. APPLICABILITY DOMAIN
[Explain how the substance falls within the applicability domain of the model]
- Descriptor domain:
- Structural and mechanistic domains:
- Similarity with analogues in the training set:
- Other considerations (as appropriate):

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

Principles of method if other than guideline:

- Software tool(s) used including version: EPISuite v4.11
- Model(s) used: BIOWIN v4.10
- Model description and Justification of QSAR prediction: see field 'Justification for type of information' and 'Attached justification'
Ready biodegradability prediction from BIOWIN module in EPISUITE model.
VEGA tool was also used to estimate whether substance was readily biodegradable. However, similar molecules with known experimental values were not found in the training set. Where similar types of molecules, such as metals or cyclic chemistries in both fragments and substances were reported, estimates and experimental values for these substances were reported as 'P', perisistent, or vP, very persistent. The metallo-organic substances include: CAS no: 2155-70-6; CAS no. 3634-67-1 and CAS no. 56-35-9, which all had experimental and estimated results showing persistence. The halogenated cyclic substance CAS no. 309-00-2, had both experimental and predicted values that show very persistent behavior. Based on the metallocene ligand chemistry, which is very resistant to oxidation, these predictions for the training set substances containing halogenated naphthenics and metallo-organics as identified above support the conclusion that the bis(1-butyl-3-methyl cyclopentadienyl) zirconium dichloride is not readily biodegradable.

Key result

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Validity criteria fulfilled:

not applicable

Interpretation of results:

not readily biodegradable

Conclusions:

QSAR predictions using BIOWIN in EPISUITE, OECD QSAR toolbox, and IRFMN model in VEGA indicate this substance is not readily biodegradable.

Executive summary:

QSAR predictions using BIOWIN in EPISUITE, OECD QSAR toolbox, and IRFMN model in VEGA indicate this substance is not readily biodegradable.

Description of key information

Based on QSAR BIOWIN model predictions, not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Based on QSAR predictions, substances is not readily biodegradable.