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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

Numerous patient cohorts and occupationally exposed persons clearly reacted positively to 4-Aminoazobenzene in concentrations of 0.25 - 2 % in vaseline or methylethylketone in the epicutaneous test. Moreover, several case descriptions exist in which positive reactions by 4-Aminoazobenzene in concentrations of 0.25 - 5 % could be triggered in individuals with dermatitis (Conde-Salazar et al., 1995; Kousa and Soini, 1980; BUA, 1998). No animal study with relevance for evaluation exists.

Justification for classification or non-classification

Based on human evidence of postive skin reactions, positive structural alert for skin sensitisation (aromatic amine) as well as classification of structurally related substances (i.e. aniline) classification of 4 -aminoazobenzene as skin sensitizer according to both Annex VI to 67/548/EEC and Annex I to the CLP-regulation is warranted.