Registration Dossier

Administrative data

skin sensitisation
other: in silico predictions
Type of information:
Adequacy of study:
supporting study
2 (reliable with restrictions)
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference Type:
study report
Report Date:

Materials and methods

Principles of method if other than guideline:
Estimated by employing Vega QSAR statistical model and Toxtree decision rule system.
GLP compliance:

Test material


Results and discussion

Any other information on results incl. tables

Vega predicted the target 2-chloro-4-(1H-pyrazol-5-yl)benzonitrile as skin sensitizers. However,the prediction was assessed as not reliable (ADI = 0.33)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 predicts the skin sensitization according to decision rules based on the identification of Structural Alerts (SA) for skin sensitizationas defined by Enoch SJ et al.[1].As one or more SAs embedded in a molecular structure are recognised, the system flags the potential skin sensitization activity of the chemical. Toxtreepredicted the target 2-chloro-4-(1H-pyrazol-5-yl)benzonitrile asNOTskin sensitizers, since it did not identify any skin sensitization reactivity domain alert. A detailed assessment of the reliability of the prediction is not provided by Toxtree.

[1]Enoch SJ, Madden JC, Cronin MT (2008) Identification of mechanisms of toxic action for skin sensitisation using a SMARTS pattern based approach, SAR QSAR Environ Res. 19(5-6):555-78.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Migrated information Criteria used for interpretation of results: expert judgment
In the consensus assessment only reliable predictions are to be taken into account. In the case of the target 2-chloro-4-(1H-pyrazol-5-yl)benzonitrile, Vega prediction resulted to be not reliable, while Toxtree did not identify any skin sensitization reactivity domain alert, leading to a NEGATIVE prediction for skin sensitization. A detailed assessment of the reliability of the consensus prediction was not possible.