Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

The substance 1-phenyl-3-methyl-5-pyrazolone induced delayed contact hypersensitivity based on Local Lymph Node Assay (LLNA) key study (OECD Guideline 429, GLP, Klimisch 1) results.

It is classified as category 1B as skin sensitizer according to CLP and REACh regulations.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the two key studies results, 1-phenyl-3-methyl-5-pyrazolone induced delayed contact hyperactivity in Local Lymph Node Assay (LLNA) and showed no ocular reactions in Buehler Test. However, the substance is classified as skin sensitizer as category 1B according CLP and REACh regulations. Indeed, the LLNA is a reference test according to current REACh requirements.