Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation
Remarks:
other: prediction by QSAR
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Skin sensitization has been estimated according to the results of to validated profilers for this endpoint: “Protein binding by OASIS” and “Skin sensitization alerts implemented by Toxtree”.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Reference:
Composition 0
Qualifier:
no guideline required
Principles of method if other than guideline:
“Protein binding by OASIS” and “Skin sensitization alerts implemented by Toxtree” are two profilers relevant for skin sensitization.
“Protein binding by OASIS” includes categories or chemical mechanism of protein binding particularly relevant for skin sensitization. Toxtree decision rule system identifies alerts for skin sensitization using a SMARTS pattern based approach. “Skin sensitization alerts” is based on the identification of structural alerts for skin sensitization as described in Enoch et al (Enoch SJ et al., SAR & QSAR Environ Res. 2008;19(5-6), 555-78).
GLP compliance:
not specified
Type of study:
not specified
Test material information:
Composition 1

No structural alerts were identified for ursodeoxycholic acid.

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: expert judgment
Conclusions:
According to “Protein binding by OASIS”, all the target chemicals were classified as “no binding”, since they did not answer any of the categorization criteria. No structural alerts were identified for the five biliary acids according to “Skin sensitization alerts”. In fact no alerts were identified for acyl transfer agent, nor for a potential Michael acceptor, nor for Schiff base formation, nor for potential second-order nucleophilic aliphatic substitution reaction, nor for nucleophilic aromatic substitution reaction.
Thus, it was concluded that the five biliary acids are NOT SKIN SENSITIZER.
Executive summary:

“Protein binding by OASIS” and “Skin sensitization alerts implemented by Toxtree” are two profilers relevant for skin sensitization.

“Protein binding by OASIS” includes categories or chemical mechanism of protein binding particularly relevant for skin sensitization. Toxtree decision rule system identifies alerts for skin sensitization using a SMARTS pattern based approach. “Skin sensitization alerts” is based on the identification of structural alerts for skin sensitization as described in Enoch et al (Enoch SJ et al., SAR & QSAR Environ Res. 2008;19(5-6), 555-78).

According to “Protein binding by OASIS”, all the target chemicals were classified as “no binding”, since they did not answer any of the categorization criteria. No structural alerts were identified for the five biliary acids according to “Skin sensitization alerts”. In fact no alerts were identified for acyl transfer agent, nor for a potential Michael acceptor, nor for Schiff base formation, nor for potential second-order nucleophilic aliphatic substitution reaction, nor for nucleophilic aromatic substitution reaction.

Thus, it was concluded that the five biliary acids are NOT SKIN SENSITIZER.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

“Protein binding by OASIS” and “Skin sensitization alerts implemented by Toxtree” are two profilers relevant for skin sensitization.

“Protein binding by OASIS” includes categories or chemical mechanism of protein binding particularly relevant for skin sensitization. Toxtree decision rule system identifies alerts for skin sensitization using a SMARTS pattern based approach. “Skin sensitization alerts” is based on the identification of structural alerts for skin sensitization as described in Enoch et al (Enoch SJ et al., SAR & QSAR Environ Res. 2008;19(5-6), 555-78).

According to “Protein binding by OASIS”, all the target chemicals were classified as “no binding”, since they did not answer any of the categorization criteria. No structural alerts were identified for the five biliary acids according to “Skin sensitization alerts”. In fact no alerts were identified for acyl transfer agent, nor for a potential Michael acceptor, nor for Schiff base formation, nor for potential second-order nucleophilic aliphatic substitution reaction, nor for nucleophilic aromatic substitution reaction.

Thus, it was concluded thatthe five biliary acids are NOT SKIN SENSITIZER.

Justification for selection of skin sensitisation endpoint:
“Protein binding by OASIS” and “Skin sensitization alerts implemented by Toxtree” are two validated profilers relevant for skin sensitization.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the results of a QSAR prediction, ursodeoxycholic acid is not classified for skin seinsitization, according to Regulation 1272/2008/EC.