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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
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 : VEGA

2. MODEL: Version 1.1.4 (build date 13.02.17)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL : CCC\C=C\C=O

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: Ready Biodegradation (OECD 301C Modified MITI (I) Test)
- Unambiguous algorithm: The model applies a combination of structural alerts and statistical algorithms. The algorithm is not clear, but the model is publically available and thus reproduceable.
- Defined domain of applicability: Prediction is within the domain ranges.
- Appropriate measures of goodness-of-fit and robustness and predictivity:

5. APPLICABILITY DOMAIN
- Descriptor domain: Similarity index: 0.862 - strongly similar compounds with known experimental value in the training set have been found.
- Structural and mechanistic domains: Global Applicability Domain (AD) Index: 0.929 - the predicted compound is into the Applicability Domain of the model.
- Similarity with analogues in the training set:
----- Accuracy of prediction for similar molecules: 1 - accuracy of prediction for similar molecules found in the training set is good.
----- Concordance for similar molecules: 1 - similar molecules found in the training set have experimental values that agree with the predicted
value.
----- Atom Centered Fragments similarity check: 1 - all atom centered fragment of the compound have been found in the compounds of the training
set.

6. ADEQUACY OF THE RESULT
The prediction is classified as Possible Readily Biodegradable. The prediction falls within the domain range and is considered reliable. Therefore, this prediction is considered adeqaute.

Data source

Reference
Reference Type:
other: model
Title:
VEGA
Year:
2017
Bibliographic source:
Ready Biodegradability model (IRFMN) 1.0.9

Materials and methods

Test guideline
Guideline:
other: REACH Guidance on QSARs R.6

Test material

Constituent 1
Chemical structure
Reference substance name:
trans-hex-2-enal
EC Number:
229-778-1
EC Name:
trans-hex-2-enal
Cas Number:
6728-26-3
Molecular formula:
C6H10O
IUPAC Name:
trans-hex-2-enal
Test material form:
liquid
Specific details on test material used for the study:
SMILES: CCCC=CC=O

Results and discussion

% Degradation
Parameter:
probability of ready biodegradability (QSAR/QSPR)
Remarks:
Possible Readily Biodegradable
Remarks on result:
readily biodegradable based on QSAR/QSPR prediction

Any other information on results incl. tables

Two structural alerts were identified as possibly ready biodegradable: Possible RB alert no. 14 (acetaldehyde); Possible RB alert no. 20 (butane). Experimental values for both of these chemicals are reported within VEGA, which states that they are readily biodegradable. No alerts for non ready biodegradable or possibly non-ready biodegradable were triggered. The model falls within the domain range. Therefore, the prediction of Possible Readily Biodegradable is accepted with high reliability.

Applicant's summary and conclusion

Conclusions:
Two structural alerts were identified as possibly ready biodegradable: Possible RB alert no. 14 (acetaldehyde); Possible RB alert no. 20 (butane). Experimental values for both of these chemicals are reported within VEGA, which states that they are readily biodegradable. No alerts for non ready biodegradable or possibly non-ready biodegradable were triggered. The model falls within the domain range. Therefore, the prediction of Possible Readily Biodegradable is accepted with high reliability.
Executive summary:

Two structural alerts were identified as possibly ready biodegradable: Possible RB alert no. 14 (acetaldehyde); Possible RB alert no. 20 (butane). Experimental values for both of these chemicals are reported within VEGA, which states that they are readily biodegradable. No alerts for non ready biodegradable or possibly non-ready biodegradable were triggered. The model falls within the domain range. Therefore, the prediction of Possible Readily Biodegradable is accepted with high reliability.