Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Vega predicted the target Phenyl(pyridin-2-yl)acetonitrile as skin sensitizers. However, the prediction was assessed as not reliable (ADI = 0.34) due to the fact that only moderately similar compounds with known experimental value in the training set have been found and a prominent number of atom centered fragments of the compound have not been found in the compounds of the training set or are rare fragments.

Toxtree predicted the target Phenyl(pyridin-2-yl)acetonitrile as not skin sensitizer, since it did not identify any skin sensitization structural alert. A detailed assessment of the reliability of the prediction is not provided by Toxtree.


Migrated from Short description of key information:
Skin sensitization was estimated by employing two predictors: Vega QSAR statistical model and Toxtree decision rule system.

Vega model predicts skin sensitization by an Adaptive Fuzzy Partition (AFP) model, which provides a qualitative prediction, i.e. positive or negative, based on the belonging degree to the sensitizer and non-sensitizer classes. Vega assesses the reliability of the prediction according to a global Applicability Domain Index (ADI), which ranges from 0 (not reliable) to 1 (fully reliable) taking into account many parameters, e.g. descriptor ranges, chemical similarity, fragments similarity, etc.
Toxtree predicts the skin sensitization according to decision rules based on the identification of Structural Alerts (SA) for skin sensitization as defined by Enoch SJ et al.17. As one or more SAs embedded in a molecular structure are recognised, the system flags the potential skin sensitization activity of the chemical.

Justification for selection of skin sensitisation endpoint:
Skin sensitization was estimated by employing two predictors: Vega QSAR statistical model and Toxtree decision rule system.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

In the weight of evidence assessment only reliable predictions are to be taken into account. In the case of the target Phenyl(pyridin-2-yl)acetonitrile, Vega prediction resulted to be not reliable; thus, based on Toxtree prediction it was concluded that the target Phenyl(pyridin-2-yl)acetonitrile is predicted as NOT SKIN SENSITIZER. A detailed assessment of the reliability of the prediction was not possible.